A Clinical Introduction to Psychosis: Foundations for Clinical Psychologists and Neuropsychologists

This practical guide outlines the latest advances in understanding and treating psychotic symptoms and disorders, articulating step-by-step the clinical skills and knowledge required to effectively treat this patient population. A Clinical Introduction to Psychosis takes an evidence-based approach that encourages a wider perspective on clinical practice, with chapters covering stigma and bias, cultural factors, the importance of social functioning, physical health, sleep, and more. A broad array of treatment modalities are discussed, including cognitive behavioral therapy, cognitive remediation, psychosocial interventions, trauma-informed therapies, and recovery-oriented practice. The book also provides a concise overview of the latest advances regarding cognitive profiles in people with psychotic disorders, the developmental progression of cognitive abilities, and the clinical relevance of cognitive dysfunction. The book additionally familiarizes readers with issues and controversies surrounding diagnostic classification, transdiagnostic expression, and dimensional assessment of symptoms in psychosis.

• Provides treatment and assessment methods for psychotic symptoms and disorders
• Looks at how psychosis develops and the impact of stigma on clinicians and clients
• Studies the links between trauma, PTSD, and psychosis, as well as sleep and psychosis
• Covers digital technologies for treating and assessing psychosis
• Outlines strategies for treating visual and auditory hallucinations
• Examines how to incorporate consumer and clinician perspectives in clinical practice

• Language: English
• Publisher: Academic Press
• Release date: Oct 19, 2019
• ISBN: 9780128150139

Book preview

day.

Section 1

The Basics

Chapter 1

What Is Psychosis?

Part One: Lived Experience Perspectives

Abstract

As clinical and neuropsychologists, one of the many skills you need is the ability to listen to your clients, to appreciate their personal experience and understanding of living with and recovery from psychosis. As with any source of evidence, information drawn from subjective experience of psychosis must then be evaluated and integrated with information available from clinical and research sources. To lead by example, we begin with two first-person accounts, given by people with lived experience of a psychotic disorder and psychotic symptoms (in the absence of a diagnosis), respectively. To understand the context shaping these personal accounts, we suggested that contributors could describe their personal experience of psychosis along with other aspects of their lives that they wished to disclose, but to also include some ‘take-home’ messages for psychologists of the future.

Keywords

Psychosis; Symptoms; Schizophrenia; ‘Take-home’ message; Voice hearers; Stigma

When you talk, you are only repeating what you already know. But if you listen, you may learn something new

Dalai Lama

Past, Present, and Future

Clair de la Lune    Western Australia, Australia

I am a 56-year-old woman who ‘lost’ most of her twenties to undiagnosed mental illness. My family and friends didn’t understand what was going on with me and awareness of mental illness in Australia was not as advanced in the 1980s as it is today. I was finally diagnosed with a mild form of schizophrenia when I was 28 years of age.

I grew up on a sheep farm in the South-West of Western Australia, enjoying country life and my ponies. I graduated from school, then worked on the farm and had various other jobs for some years. At age 21, I went to university to study English and found my studies challenging—writing properly constructed essays was difficult and I was confused by this as I was able to write well at school. I began feeling depressed and then my parents separated, so I left university after 1 year. I then had two jobs as a nanny, but it was becoming obvious that something was not right with me.

Then the illness really began to manifest itself as I lacked motivation, became withdrawn and uncommunicative, was often rude and abrupt and displayed a lack of self-care. I usually went to bed at about three or four o’clock in the morning and slept in until two or three in the afternoon—such sleep patterns are common symptoms of mental illness. Symptoms such as paranoia and delusions becoming more pronounced as I began perceiving things differently. I believed the television and radio were sending me personal messages through their songs and advertisements—mostly not very nice messages although some could be positive and gave me brief respite from my usual ‘down’ state of mind. I didn’t trust my family and occasionally thought people were trying to ‘get me’. I remember waiting at a bus stop when some young men drove by and one of them yelled out at me ‘He's going to shoot you!’ That was how I heard it anyway, which added to my already growing fears. Unlike many people diagnosed with schizophrenia, I did not hear voices, which is indicative of how symptoms of mental illness are unique to the individual.

I was frightened to go out during the day so often ventured out at night, sometimes not knowing where I was—a dangerous way of living for a young woman. During this period, I went missing—I met someone at a bar and stayed with them for three weeks without informing anyone where I was. I was no longer aware of social obligations such as letting people know where I was. After going missing, I was referred to a psychiatrist who I saw unwillingly as I didn’t think there was anything wrong with me. The psychiatrist thought I may have schizo-effective disorder or a schizoid personality and he offered me medication, which I refused. In retrospect, I wish I had taken some medication then despite the side effects such as weight gain.

Finally, my mother described my symptoms to a consultant psychiatrist she met and he thought I may have schizophrenia and sent a nurse around to see me. I wasn’t pleasant to the nurse, so then the psychiatrist himself came to see me. Sometime after that visit, two young policemen came to my flat. They told me they were taking me to a psychiatric hospital. I didn’t think I was sick (thinking this way when mentally ill is known as ‘lack of insight’—I don’t like this term as I think this symptom is simply another manifestation of your different perception and is not a lack of anything—semantics!), so I refused to go. They were insistent and packed a bag for me, so I went with them to the nurse's car and was given a police escort to hospital, feeling confused about what was happening to me.

When first given medication in hospital, I would put the tablet under my tongue and spit it out in the bathroom. This is common behaviour and the nurses soon gave me a liquid medication instead. Within a few days I responded to the medication and my mother noticed quite a dramatic change in me. We had dinner together and had our first proper conversation in years. I spent 5 weeks in hospital and was released when I consented to having two injections in the buttocks. I continued to have injections of medication every 2 weeks for some years until I started taking an antipsychotic pill every day. On release, I was put on a disability pension, saw a psychiatrist regularly as an outpatient, and began the slow return to ‘normal’ life—something I think I am still doing after all these years. I remember seeing a woman with schizophrenia interviewed on television once, talking about how she felt her personality was ‘shattered’ by her illness which I think is a good description. I tried to ‘become me’ again and due to the unusual experiences and altered brain chemistry I think it unlikely anyone would be the same person as before.

Today I am on a daily low dose of aripiprazole and although I have had a couple of hiccups along the way, I haven’t been treated again in a psychiatric hospital. I have worked part-time looking after children and cared for my grandmother for a couple of years. I now do some mental illness advocacy and have spoken at universities, schools and a couple of Rotary Mental Health Forums as I believe educating and humanising the experience will help to foster understanding and contribute to reducing the stigma so often associated with mental illness. I contributed to a book called FASCInATE (Fremantle Arts Centre Press, 2017), which had poetry and prose written by people with mental illness about their experiences, under the guidance of a literary tutor. Although this project was not meant to be therapeutic, the act of writing and talking about our experiences was rather cathartic. The book was published and distributed throughout high schools in Western Australia in 2006 to educate young people about mental illness.

I believe that scientific research into the brain and mental illness will one day lead us to better treatments and outcomes for people with mental illness so I participate in, and advocate for, schizophrenia research. I also promote the involvement of people with lived experience of mental illness in scientific research, not just as participants but as partners, as they can give a unique perspective and create a sense of urgency.

The approach to psychiatric treatment in 1989, when I was diagnosed, was less holistic than today. Psychotic illnesses are complex diseases, often requiring different modes of care and I believe psychology is an important part of this. I wish I had been referred to a psychologist after I was first treated, to deal with the consequences of my illness both past, present, and future. Stigma, and consequent self-stigma, is an issue for people with mental illness as is the guilt associated with out-of-character things you may have done when you are sick. When responding well to treatment, there may be guilt associated with realising what family and friends have gone through as a result of your illness. Many people experience grief at their loss of capacity and life expectations, and there is also the loneliness associated with living with a mental illness. These issues need to be addressed. When I was eventually referred to a psychologist to deal with issues arising from my illness, I felt a sense of relief as I was listened to, and my experience and feelings were validated.

When in psychosis, a person's perception may be altered. What a well person may think is a reasonable statement, comment, etc. may be perceived very differently by someone in psychosis. Your words may have a different and very impactful meaning (frightening, prescient, etc.) for them. What seems irrational to you is real and rational to them and a calm and nonjudgemental response is so important. I have found over the years that some people often ‘see you as your illness’ and forget that the illness is a part of my life but I am not my illness—I am more than that. Sometimes I feel like saying ‘I was once like you – schizophrenia-free – mental illness was not a part of my life’. I also dislike being called ‘a schizophrenic’ (the media tend to use this term with all its negative connotations); this, once again, indicates to me that I am only my illness. I prefer—I suffer from schizophrenia, I live with schizophrenia, or I have schizophrenia.

Some of the compassionate and inspirational people I have been privileged to meet because of my illness include psychiatrists, nurses, psychologists, social workers, occupational therapists, scientific researchers and, of course, my brave fellow sufferers. These people have given me hope and renewed my faith in humanity. My experience of schizophrenia has been very challenging, but I have learnt about empathy and tolerance and what it is to be truly human.

Reference

Fremantle Arts Centre Press. FASCInATE: Friends of Alma Street Centre Inspiring Action Towards Equity. North Fremantle, WA: Fremantle Arts Centre Press; 2017.

My Hidden Superpower

Evie Glasshouse    School of Psychology and Exercise Science, Murdoch University, Murdoch, WA, Australia

When we think of someone hearing voices, we generally think of the worst-case scenario; the raving lunatic on the street corner or the serial killer in the horror film. This image of the ‘crazy voices in your head’ is so prevalent that I did not even recognise that I was a voice hearer until my later life: simply because my experience was not what I had seen in the movies.

I have been hearing voices for as long as I can remember. The best way I can describe my experience is to imagine having a radio switched on in the corner of your room 24/7. Most of the time, the sound is set just below the threshold of hearing: you can make out that there is talking, but you have to focus to make out the words. However, in times of stress, this radio gets turned up automatically: making it very hard to concentrate or focus on anything else. I am fortunate as my voices are mostly pleasant, but some activities can be hampered by having what seems like an auditorium of people in your head, all talking at once!

My voices likely originated as a coping mechanism from my childhood experiences. I was left alone for extended periods of time, and so, desperate for human interaction, I imagined people to play with instead. Over time, I began to carry these made-up people around with me inside my head wherever I went, like my own personal advisory committee. I was never lonely or bored, because I always had someone to talk to. However, this only served to isolate me further from my peers as I was labelled ‘the weird kid’. I was withdrawn and depressed, which likely only made me rely on my voices more, further isolating myself. It was a vicious cycle.

My breaking point with my voices was when I was 25. I had just broken up with my partner of 11 years and was in the middle of my final year of my university degree. While for me it is normal to hear voices daily, I heard a voice that was particularly loud and clear. This voice seemed to belong to an individual person, rather than my other voices which I considered a part of myself. This voice told me in an ominous tone, ‘I have seen what happens next, and you’re not going to like it’. The experience rattled me so much that I immediately checked myself into my local emergency mental health clinic.

At the clinic, I was asked concerning questions. ‘Do the voices tell you to hurt people? Do they tell you to hurt yourself?’ For my voices, this was unthinkable. My primary concern was that this new voice experience was abnormal for me and indicated something was very wrong. Nevertheless, as I was in no immediate danger, I was discharged with some antipsychotics and no further follow-up. I felt lost and terrified—was I going to end up like the people in the movies? I was the right age for the onset of mental illness, and this thought was crippling. What if I could never be normal again?

Luckily for me, I searched up a psychology clinic, which specialised in voice hearing. After an intensive course of cognitive behavioural therapy, I realised that my voices were trying to help me, not harm me. Discovering the link between my childhood experiences and my voices was crucial to my personal acceptance that what I was hearing wasn’t ‘bad’ or ‘good’, it just is something that happens. Managing my anxiety and depression in turn helped my voices become more manageable.

When I get a chance to speak about my voices, people always ask if I have found a way to get rid of them. But I consider my voices an integral part of me, and I would feel very lonely without their presence. I wouldn’t be the person I am today without growing up with these unusual experiences.

I believe that the view that voices are something to ‘fix’ should be shifted towards asking what voices may represent instead, and helping an individual see their voices in a positive or helpful light. For me, my voices becoming more frequent or louder are a warning signal that I am not coping with daily stress—and this helps me focus on making the changes I need to in order to feel better. This may not be true for every voice hearer, but this may serve to reduce the stigma for people like me who hear unusual things. Reassurance that you are not crazy for hearing voices is very comforting and changing from the concept that voices are an illness may help individuals who do hear voices to feel safe to seek the help they require.

While my personal journey certainly is not finished, I now live comfortably with my daily voice experience. They are very helpful when I practice presentations or helping me outline a new idea for a novel: who can say that they have a personal cheerleading team in their heads? I view my voices as my secret superpower rather than a hindrance, and I would hope that other voice hearers can one day feel the same about their own experiences too.

I am now embarking on my postgraduate degree working in the cognitive neuropsychology field, where I am aiming to find brain areas, which generate a voice hearing experience in some individuals and not others. Without my voice hearing experience, I likely would not be pursuing this line of research. A few years ago, I thought I was doomed to be a victim of worsening mental illness, but now it motivates me to help others who have similar experiences.

My take-home message to future clinicians who hope to work with voice hearers in the future would be to try to see the experience of hearing voices as more than a symptom needing to be cured. Not all voices are bad or mean, nor need to be removed entirely from an individual's life. To the voice hearer, I hope that experiences such as mine help to reduce the stigma we have for our unusual experiences, which make us the unique person we are today.

Part Two: Current Conceptualisation of Psychosis—Clinical and Research Perspectives

Clara S. Humpston*; Henry J. Jackson†    * Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom

† School of Psychological Sciences, University of Melbourne, Melbourne, VIC, Australia

Abstract

The focus of this chapter is to introduce the symptomatology and phenomenology of psychotic disorders, as well as approaches used to diagnose and assess them. We consider different ways that psychotic symptoms and disorders have been conceptualised and arguments for both categorical and dimensional assessment systems, highlighting key areas of debate. Then we turn attention to the heuristic model of clinical staging and provide a brief discussion of its advantages and limitations in clinical practice. We also spotlight current sources of clinical guidelines for the management and treatment of psychosis, and underscore some key issues for psychologists. Lastly, we consider the importance of skilled communication with people with psychosis and discuss emerging evidence and tools for effective clinician–client communication.

Keywords

Psychotic symptoms; Phenomenology; Diagnostic systems; Clinical staging, guidelines

Key Learning Objectives

•To learn about current conceptualisations of psychosis.

•To critically evaluate categorical and dimensional approaches to diagnosis.

•To introduce clinical practice guidelines in the management of psychotic disorders.

•To appreciate strengths and limitations of staging models of psychosis.

•To understand ways to improve communication with people with psychosis.

Introduction

‘Psychosis’ is a generic term that refers to distortions and impairments of thought, feeling, and behaviour leading to a loss of contact with consensual reality. It is signified by delusions, hallucinations, thought disorder, grossly disorganised or abnormal motor behaviour, and negative symptoms (APA, 2013). The term can be confusing as it is used to refer to both diagnostic categories and to individual symptoms (experiences) with variable levels of severity, duration, and clinical significance. At the categorical level, schizophrenia-spectrum disorders include schizophrenia, schizophreniform disorder, schizoaffective disorder, delusional disorder, brief psychotic disorder, substance/medication-induced psychotic disorder, and schizotypal (personality) disorder, psychotic disorder due to another medical condition, catatonia, and other specified and unspecified schizophrenia spectrum and other psychotic disorders (APA, 2013; WHO, 2018). Schizophrenia has received various narrower and broader definitions over time. It is the psychotic disorder that attracts most attention and one reason may be that it is the most common; for example, the lifetime prevalence of schizophrenia is about 0.9%, compared to 0.3% for schizoaffective disorder (Perälä et al., 2007). Nevertheless, one should not neglect the other schizophrenia-spectrum disorders as the terms ‘psychotic disorder’ and ‘schizophrenia’ are not equivalent. Importantly, psychotic symptoms can be found in a range of other disorders, although not as a defining feature, most notably in mood disorders (major depression and bipolar disorder), substance-related and addictive disorders, posttraumatic stress disorder, borderline personality disorder, and neurocognitive disorders (e.g. Alzheimer's disease). At the symptom level, psychotic symptoms and psychotic-like symptoms are also found in the general population and people with these experiences may or may not require care.

Usage of the term ‘psychosis’ is highly variable and the subject of ongoing debate.

This chapter, and indeed this book, is concerned with current conceptualisations of psychosis, with a particular emphasis on the schizophrenia spectrum disorders. It is important to recognise the contributions of seminal figures in the field, including Emil Kraepelin, credited with the dementia praecox concept; Eugen Bleuler, who redefined dementia praecox as schizophrenia; and Kurt Schneider who identified 11 first-rank symptoms, presumed characteristic of schizophrenia. Current classificatory systems for schizophrenia and related disorders have their roots in this early work (see Additional Reading), but have evolved over time in an effort to improve reliability, validity, and clinical utility.

Over the last 30–40 years various psychological disciplines, including clinical, experimental, and neuro-psychologists, have made important contributions as clinicians and researchers working with people with psychotic disorders and symptoms to understand their experiences. Furthermore, they have developed and evaluated a wide range of assessments, treatments, interventions and services, thus contributing to a deeper understanding of these disorders.

Multiple Conceptualisations of Psychosis

The purpose of this section is to briefly introduce four different perspectives on psychosis: the neurobiological, phenomenological, cognitive, and socio-developmental accounts. Each provides a different level of explanation; yet there is considerable overlap. Consequently, it is important to take an integrative approach (the theme of Chapter 2), both in research and clinical practice.

A Neurobiological View of Psychosis

Schizophrenia and related psychotic disorders have long been conceptualised as neurobiological or ‘brain’ illnesses, involving changes in genetic, molecular, cellular, and circuitry function. Indeed, there has been a vigorous and ongoing debate about the fundamental nature of schizophrenia: ‘Is it a classical organically based biomedical disorder with clean boundaries due to the effects of a single etiologic agent, or is it the severe end of a spectrum of syndromes that aggregate together in families?’ (Kendler, 2015, p. 11). For example, early genetic models rested on the assumption of a single gene for schizophrenia, whilst later proposals have favoured a polygenic model (Gottesman & Shields, 1972; Kendler, 2015). Increasing evidence suggests that the risk of schizophrenia is more likely continuous and polygenic (International Schizophrenia Consortium, 2009)—involving a large number of common single-nucleotide polymorphisms (SNPs), each having a very small effect, with a smaller contribution from rare copy number and single-nucleotide variants (Purcell et al., 2014).

Single-nucleotide polymorphisms are variations of a single nucleotide (building blocks of DNA) that occur at specific locations within a genome.

Measures of brain structure and function provide important insights into the underlying mechanisms of psychotic disorders. A comprehensive review of this literature is beyond the scope of this chapter; however, recent advances may have important implications for clinical practice. For example, new strategies are currently being trialled to identify distinct subgroups—or biotypes—of people with psychosis sharing more similar characteristics, using biomarkers and genetics (e.g. Tamminga et al., 2017), with the aim of designing more individually tailored treatments.

Biotypes represent more biologically similar subgroups of psychosis than traditional diagnostic categories.

Nonetheless, neurobiological models of schizophrenia clearly recognise that the emergence of psychotic symptoms involves an interplay between genetic vulnerability and exposure to (environmental or psychosocial) stressors (Howes, McCutcheon, Owen, & Murray, 2017). However, phenomenology is often only acknowledged superficially in these accounts, at least when viewed from a philosophical perspective, which is considered next.

Phenomenology is the study of consciousness and the objects of direct experience.

Phenomenological Perspective and Self-Disturbance Model of Psychosis

In stark contrast to neurobiological conceptualisations, phenomenological perspectives on psychosis emphasise a basic disturbance of one's minimal self (Nelson, Parnas, & Sass, 2014).

The minimal self is the most basic sense of having experiences that are one's own.

The self-disturbance model (or ipseity disturbance, Latin ipse—self or itself) is deeply embedded in the phenomenological tradition and continental philosophy and is a concept that may appear alien to many trainees in clinical or neuropsychology and psychiatry. Likewise, the idea of minimal self (as opposed to narrative self) is unfamiliar to many. In fact, it has been described as a disappearing heritage of modern psychiatry (Parnas, 2011) since self-disturbances featured in DSM-III as a part of the descriptions of schizophrenia, but less so since then. According to this view, these symptoms often involve a permeation or destruction of one's ego boundary, i.e. the ability to differentiate and demarcate between self and other, the internal and the external ‘worlds’. Bleuler classically reported patients complaining of being only ‘reflections of themselves’, or having ‘lost their individual self’ (for examples see Henriksen & Parnas, 2012). Though now given less prominence in diagnosis, prototypical ‘first-rank’ symptoms involve severe disruptions of the ownership and agency of thought (thought insertion, withdrawal, broadcast, etc.) and of action/volition (passivity phenomena, ‘made’ actions). Without an intact sense of agency and ownership, a fragmentation of the minimal self is perhaps an unsurprising end result.

Narrative self: the sense that we have of ourselves as having an evolving story through past and future.

Agency: the sense that mental events and behaviours, such as actions and thoughts, originate from oneself, i.e. one is the agent and has first-person experience.

Ownership: the sense that one is physically responsible (‘owns’) for the mental events one initiates.

The minimal self is viewed as being severely affected in schizophrenia-spectrum psychoses.

Sass and Parnas (2003) proposed a model of self- or ipseity-disturbance consisting of three integral factors, all of which contribute to a disordered selfhood considered an essential feature of schizophrenia spectrum disorders. The first is termed hyperreflexivity, which refers to an exaggerated self-consciousness where normally tacit and nonvolitional processes, such as inner thought, become a focus of intense attention and scrutiny. In other words, what is tacit becomes explicit. A second complementary process, termed diminished self-affection (unrelated to ‘affection’ in an emotional sense), refers to a decreased feeling of existence as a subject of self-awareness or an agent of thoughts and actions. The final factor, disturbed ‘grip’ or ‘hold’, refers to fundamental distortions in one's relations to external reality and how one experiences external stimuli, accompanied by alterations in the ‘reality-status’ of the world. Such self-disorders are thought to bear some degree of specificity to schizophrenia-spectrum psychoses, rather than bipolar disorder or other psychological disorders, and have significant predictive validity for transitioning to psychosis from nonspecific prodromal phases (e.g. Nelson, Thompson, & Yung, 2012). Nevertheless, their overlap with nonpsychotic syndromes remains a topic of debate, for example with depersonalisation–derealisation.

The self-disturbance model is not a widely adopted clinical approach at present; however, assessing disturbances in the sense of minimal self in those at clinical high risk or in the first episode of psychosis could provide improved specificity for diagnosis (in turn, affecting prognosis and treatment), and is therefore a topic of much research and debate (Sass, Borda, Madeira, Pienkos, & Nelson, 2018).

Hyperreflexivity refers to an exaggerated self-consciousness.

Diminished self-affection involves a decreased feeling of existence as a subject of self-awareness.

Cognitive Approaches to Psychosis

Cognitive approaches to psychosis emphasise the role of cognitive, social, and emotional processes in the onset and persistence of psychotic symptoms. According to these models, it is the interpretation and meaning given to events and experiences, i.e. appraisals, that play a critical role in the transition from anomalous thoughts and experiences to psychotic symptoms (Chadwick & Birchwood, 1994; Garety, Kuipers, Fowler, Freeman, & Bebbington, 2001). Thus, individuals who have psychotic experiences that are appraised as positive and helpful are unlikely to seek treatment. According to this view, psychosis exists on a continuum with ‘normal’ experiences in the general population.

Appraisals refer to the emotional–motivational significance given to stimuli and drives emotional responses.

Whilst the details of specific cognitive models vary, they all provide a psychological description of subjective experiences, which serves as bridge between the phenomenological experience and the associated neurobiology (Garety et al., 2001). For example, Garety and colleagues proposed two ‘proximal routes’ to the development of positive symptoms in schizophrenia, namely one combining cognitive and affective disturbances and the other via affective disturbances alone (Garety et al., 2001). The authors argued that in individuals vulnerable to psychotic experiences, there is often a triggering event that leads to distortions of cognitive processes, which may involve the sense that something inexplicable is going on in the earlier phases of psychosis (e.g. delusional mood), to the alienation and externalisation of self-generated actions and thoughts in full-blown psychosis (e.g. thought insertion).

Not surprisingly, such experiences are highly salient and sometimes very distressing, leading to high levels of emotional arousal. The individual therefore is likely to embark on a natural search for meaning in order to find explanations (and thus possible resolution) for such experiences, which is susceptible to conscious and unconscious cognitive biases. Indeed, recent research has found that the way in which an individual appraises psychotic experiences differs in people with and without a need for care (Peters et al., 2017). A tendency to appraise psychotic experiences as external, threatening/paranoid, and negative often paves ways to the persistence of psychosis and may also be related to the corresponding neurobiology of threat processing (Underwood, Kumari, & Peters, 2016), whereas individuals not distressed by their psychotic experiences have more positive, less hostile appraisals.

Emotions have also been argued to have a direct effect on the formation and maintenance of delusions and hallucinations, without a primary cognitive underpinning (Freeman & Garety, 2003). Recent longitudinal evidence, for example, has shown that baseline levels of anxiety and depression predict persistence of paranoia two years later, whilst baseline delusions did not predict later negative affect (Fowler et al., 2012). These findings suggest that negative affect isn’t simply a consequence of paranoid thinking, rather it plays a direct, causal role in the experience of this symptom (Hartley, Barrowclough, & Haddock, 2013). However, a potentially more realistic possibility is that both direct and indirect pathways link negative affect to paranoia (e.g. So et al., 2018). From the lens of the cognitive model, therefore, psychosis is viewed in terms of how we think and feel, much like other psychological problems and, importantly, it identifies underlying causal mechanisms that can be targeted in therapy.

Socio-Developmental Perspectives on Psychosis

Lastly, according to the socio-developmental view, a full understanding of the question ‘What is psychosis?’ can only be gained by incorporating a focus on early life events, social environment, and the subsequent development of an individual's psychological world and mental wellbeing. Again this psychosocial perspective may potentially link neurobiology, cognition, and personal narratives of psychosis. For example, adverse life events, particularly childhood trauma, frequently trigger the formation of unhealthy coping mechanisms and aberrant cognitive appraisals (e.g. Reininghaus et al., 2016) when evaluating self and others (an obvious example may be blaming oneself for the abuse one suffered, viewing oneself as bad or others as hostile). Whilst highly aroused, emotional states may simultaneously construct a ‘nonself’ dissociative barrier to the trauma, alter the function of key neurotransmitters involved in psychosis such as glutamate and dopamine (Howes & Nour, 2016), and damage the brain's cortical structure via neurotoxic effects (Habets, Marcelis, Gronenschild, Drukker, & van Os, 2011).

Furthermore, social adversity is not limited to childhood abuse. Cultural, political, and demographical factors (e.g. Bourque, van der Ven, Fusar-Poli, & Malla, 2012), including immigrant and/or minority ethnic status, along with the discrimination and poverty one may experience as a result, can all predispose vulnerable individuals to similar unhealthy behaviours such as cannabis use, abusive relationships, and poor mental health in general. In turn, these behaviours may bias the individual's cognitive appraisal style to perceive the outside world and other people as antagonistic. As a consequence, the socio-developmental perspective on psychosis highlights the need for clinicians to move beyond a focus on intraindividual factors relevant to psychotic symptoms, to a fuller appreciation of the person in their developmental and social context (Howes & Murray, 2014).

Social adversity is a well-established risk factor for psychosis.

Diagnosing Psychosis

Categorical Approaches: A Brief Introduction

Categorical approaches to diagnosing schizophrenia spectrum and other psychotic disorders (termed schizophrenia spectrum for short) are based on the concept that the signs and symptoms of these disorders correlate in a meaningful and reliable pattern (i.e. a syndrome), and can be distinguished from other syndromes (see Box 1.1 for a brief recap on terms and definitions).

Box 1.1

A Recap on Terms and Definitions

Categories: refer to groups of signs and symptoms that share some similar features.

Convergent validity: is demonstrated when the signs or symptoms of a category are highly correlated.

Classical category: to meet the category, all specified criteria (signs and symptoms) must be present.

Divergent validity: is demonstrated when signs and symptoms that are not supposed to be related to the category of interest are unrelated to that category.

Polythetic category: to meet the category, a certain number of symptoms or signs from a given list is sufficient (e.g. any five of eight), though none is essential.

Quasi-polythetic category: to meet this criteria, firstly a person must have one or two specified criteria (signs and symptoms), but then can have a certain number of other specified criteria. This system is adopted in the DSM-5 approach to diagnosing schizophrenia spectrum and other psychotic disorders.

Signs: what the clinician directly observes, e.g. thought disorder, gait disturbance or flattened affect

Symptoms: what the patient reports, e.g. a delusion or hallucination

Clinical and neuropsychologists worldwide use two established categorical systems for classifying schizophrenia spectrum disorders, namely the Diagnostic and Statistical Manual of Mental Disorders (5th Edition; APA, 2013) and the International Classification of Diseases (ICD, 11th Edition; WHO, 2018, https://icd.who.int/browse11/l-m/en). Full details on the symptoms and diagnostic criteria for schizophrenia spectrum disorders are provided in these sources, so they will not be reproduced here. From a descriptive psychopathological perspective, traditionally psychotic symptoms include those that are termed positive symptoms and those that are termed negative symptoms (Andreasen, 1982, 1984; Oyebode, 2014; Sims, 1988). ICD-11 has now included anomalous self-experiences. However, there is disputation about a simple grouping of symptoms into two categories, discussed in more detail in the section on Dimensional approaches below (see, e.g. Blanchard & Cohen, 2006).

Positive symptoms include hallucinations, delusions, positive thought disorder, and bizarre behaviour.

Negative symptoms include affective flattening or blunting, alogia, avolition-apathy, asociality, and inattention.

Despite attempts to harmonise the diagnoses in DSM-5 (APA, 2013) and ICD11 (WHO, 2018; see Biedermann & Fleischhacker, 2016), one can see that some disorders appear in both nosologies whilst others don’t. Moreover, where the diagnostic labels are identical, the criteria sets used to reach a diagnosis differ across the two systems. Potentially, this could lead to a patient being described with a specific psychotic disorder in ICD and another type of psychotic disorder in DSM. Additionally, various disorders listed under the schizophrenia-spectrum in both the DSM-5 and ICD-11 differ according to duration of symptoms, configuration of symptoms, the presence or absence of mood symptoms, and the influences of legal and illegal substances.

Advantages of Categorical Systems

In general, the advantages of categorical systems are that they lend themselves to efficient communication between clinicians and are consistent with the kind of practice found in other medical disciplines. They also are helpful in epidemiological studies in determining population prevalence and incidence rates, and health service provision. They also allow the examination of etiological factors, factors maintaining the conditions, and factors associated with the syndrome, e.g. age of onset, gender ratio, and course. Further, they lend themselves to tests of interrater and test–retest reliability as well as convergent and divergent validity (Jackson & McGorry, 2009).

Problems and Pitfalls With Categories (and Diagnostic Systems)

Many criticisms have been made of the categorical approach embedded in the two official nosologies of ICD-11 and DSM-5. For example, Frances (2014) asserted that the descriptive psychopathological approach has overreached itself by increasingly pathologising aspects of normal experience. Insel and colleagues (e.g. Cuthbert & Insel, 2013) have also argued for the limitations of the descriptive psychopathological approach and instead proposed a reverse engineering approach by identifying potential biological markers and then linking these to signs and symptoms—a bottom-up approach known as the NIMH Research Domain Criteria (RDoC). Others reject nosological systems entirely and would rather deal with the person in an idiographic fashion—that is, deal with the symptoms or complaints that a specific person presents with, without regard for diagnostic labelling or concern for any biological processes (Cooke & Kinderman, 2018).

Idiographic methods focus on the unique experiences and life history of each individual.

Specifically, if we turn to the categorisation of psychotic disorders, many issues have been raised. Tandon (2016) succinctly summarises these as: …‘a) unclear boundaries between disorders (e.g. between psychotic bipolar disorder, schizoaffective disorder and schizophrenia); b) enormous unexplained clinical heterogeneity within individual psychotic disorders; c) the frequent co-occurrence of mood and psychotic symptoms; and d) poorly described relationships between subclinical psychotic phenomena in the general population and defined psychotic disorders.’ (p. 133) (see also Tandon, Nasrallah, & Keshavan, 2009). Finally, the diagnosis of a specific psychotic disorder may change with subsequent episodes, which is not due to different diagnostic practices of individual clinicians but a changing clinical picture or presentation. Such change is also less likely to occur with a diagnosis of schizophrenia but more likely to be the case with other psychotic disorders, such as delusional disorder (see Fusar-Poli et al., 2016).

Dimensional Approaches: A Brief Introduction

There are a number of approaches to dimensionality of mental disorder. First, if we turn to psychopathology per se, Caspi et al. (2014) identified three higher-order factors for mental disorders (Internalising, Externalising, and Thought Disorder) along with a broad, general (transdiagnostic) psychopathology dimension, termed ‘p’ (much like the idea that general intelligence or ‘g’ comprises multiple, specific components). Similarly, Markon (2010) identified four broad superordinate dimensions of psychopathology: Internalising, Externalising, Thought Disorder, and Pathological Introversion. Finally, the Hierarchical Taxonomy of Psychopathology (HiTOP) Consortium (Krueger et al., 2018) is developing an empirical and quantitative classification of psychopathology based on dimensions rather than categories. HiTOP proposes a complex multilevel model ranging from (i) Super Spectra (higher-order dimensions) through to (vi) Symptoms (e.g. signs and symptoms) as an alternative to traditional, categorical taxonomies, though the system is not (yet) ready for use in clinical practice.

Dimensions: capture meaningful variation in symptom severity, e.g. a continuum of negative symptoms ranging from ‘not present’ to ‘present and severe’.

As regards to psychosis per se, factor analysis has often been employed to ascertain the latent structure of symptoms underlying the schizophrenia spectrum. In reviewing factor analytic studies of psychosis rating scales, Fulford et al. (2014) found that, in general, there were three to five factors, which did not differ across patients with recent-onset or chronic schizophrenia. These scales were typically the Scale for the Assessment of Negative Symptoms (SANS; Andreasen, 1983), the Scale for the Assessment of Positive Symptoms (SAPS; Andreasen, 1984), the Brief Psychiatric Rating Scale (BPRS; Overall & Gorham, 1962), and the Positive and Negative Syndrome Scale (PANSS; Kay, Fiszbein, & Opler, 1987). Of note, Blanchard and Cohen (2006) confirmed the presence of three to five factors for psychosis but found negative symptoms to be the one constant factor across studies. Although psychometrically untested, Barch et al. (2013) proposed five symptom domains for dimensional assessment of psychosis (these being hallucinations, delusions, disorganised speech, abnormal psychomotor behaviour, and negative symptoms) plus three other domains (mania, depression, and cognition) that can be applied to all psychotic disorders and have been incorporated into Section III Assessment Measures in DSM-5 (APA, 2013, pp. 742–744).

A second approach to dimensionality has been to ascertain the structure of psychosis within a general population and then compare that structure across psychosis and ‘normal’ populations. This is the so-called continuum model of psychosis. For example, using data from a very large study of adults in the general community in United States, Shevlin, McElroy, Bentall, Reininghaus, and Murphy (2017) found a general psychosis factor that was uncorrelated with five secondary, specific factors, labelled: positive symptoms, negative symptoms, disorganisation, mania, and depression. The similarity in these findings with those previously reported in patients supports the idea of a continuum between clinical and subclinical psychotic experiences.

Van Os and colleagues adduce further evidence for a continuum model (Guloksuz & van Os, 2018). They argue that schizophrenia is heterogeneous; that the concept of ‘schizophrenia’ has become reified and is considered to be a disorder of severe symptoms, severe dysfunction, and poor outcome; that it is seen as the hallmark of the psychotic disorder spectrum and attracts the most attention. They further argue that an overfocus on clinical samples has ignored the fact that within the general community there is a range of people with various degrees of subthreshold psychotic disorders/symptoms (referring not only to positive symptoms, but also to negative and disorganised symptoms); that these symptoms are intermingled with nonpsychotic symptoms, especially affective (both manic and depressive) symptoms; and, that the psychotic symptoms are often transient. Van Os and colleagues (Guloksuz & van Os, 2018; van Os & Guloksuz, 2017) highlight that many individuals identified as being at ultra high-risk (UHR) for psychosis present with anxiety and mood disorders, though a relatively small number, progress to a first episode of psychosis. Consequently, they argue that these individuals should not be seen through the ‘schizoprism’ lens (i.e. schizophrenia spectrum disorders) but treated for their depression, anxiety, and substance misuse disorder/symptoms. McGorry, Hartmann, Spooner, and Nelson (2018) reject this position, stating that UHR states are for psychosis generally, not specifically for schizophrenia.

Another line of evidence supporting a continuum model of psychosis comes from cross-sectional studies showing that people in the community may have delusions or hallucinations and be convinced of their veracity but are not distressed by them and lead productive lives (see seminal papers about delusions by Peters, Day, McKenna, & Orbach, 1999; van Os, Linscott, Myin-Germeys, Delespaul, & Krabbendam, 2009; and a review of voice hearers by Beavan, Read, & Cartwright, 2011). These findings provide further support for: (i) the notion of a continuum between normality and psychosis and, (ii) the necessity to consider the multidimensionality of delusional beliefs and hallucinatory experiences.

Finally, a recent alternative to both categorical and dimensional models is the network approach to psychopathology. In this approach, a condition like schizophrenia is construed as arising from the interactions or connectivity (i.e. a causal network) amongst the signs and symptoms of the disorder, not from an underlying disease entity (e.g. Wigman, de Vos, Wichers, van Os, & Bartels-Velthuis, 2017). Although Guloksuz, Pries, and van Os (2017) evaluate this network approach as promising, they also point out a number of pitfalls, including the (lack of) stability and reproducibility of findings.

Advantages and Disadvantages of Dimensional/Continuum Approaches

Factor analysis allows for the identification of a small number of factors (dimensions) and how strongly or weakly each sign and symptom loads on those factors. It allows for the identification of symptom profiles and how a person could score higher or lower on each factor. The most important prospect for clinicians is the possibility of creating new measures that comprehensively cover the whole span of signs and symptoms within the schizophrenia spectrum. Conversely, there is the opportunity to develop improved measurement of specific symptom groupings. For example, Blanchard and Cohen (2006) identified two subfactors within the structure of negative symptoms, namely diminished expression and anhedonia–asociality, which has driven the development of new and more precise tools for the assessment of these negative symptom dimensions (see Chapter 7). Tandon (2016) argues that clinicians could use dimensional measures to assess a patient's treatment progress over time, and such measures will have important and direct applications in research.

The limitations of factor analysis can be listed as follows: the type of symptom measures used (i.e. their breadth or narrowness of scope); the type of factor analysis and factor solution chosen; the nature of the sample selected (i.e. the narrowness or breadth of people with specific psychotic disorders examined); the phase of illness (chronic or acute), and the time frame measured by a scale (see, amongst others, Peralta & Cuesta, 2001; Blanchard & Cohen, 2006). Moreover, cross-sectional factor analytic studies assume stability of signs and symptoms (see, e.g. Shevlin et al., 2017). Finally, patients with affective psychosis, psychotic disorder due to another medical condition or substance misuse (intoxication and withdrawal) have typically been omitted from factor analytic studies—though these are all conditions where psychotic phenomena can occur.

van Bork, Epskamp, Rhemtulla, Borsoom, and van der Mass (2017) caution against acceptance of general factor modelling (e.g. the p factor of Caspi et al., 2014), arguing against overreliance on fit indices in nearly equivalent factorial models and in deciding the optimal factor structure. They state that sampling differences can lead to different theories about the nature of a general factor and that the p factor in one study is not necessarily the same p factor in another study. Furthermore, where one has positive correlations amongst symptoms, mathematically this will lead inevitably to some form of a general factor to fit the data. Theoretical interpretation of the meaning of factors is needed but so too is consideration and application of alternative models, e.g. network models, as the true underlying model may not be a factor model at all. In fact, it could be a class or admixture (class and dimensions) model.

Additional Considerations

Diagnosing Psychosis Across Cultures

Culture refers to the customary beliefs, attitudes, values, goals and practices and social norms, of a racial, religious, or social group. It affects both the form (the type of symptoms) and the content (themes, beliefs, subjective experience) of psychotic symptoms, so there are differences in the prevalence of symptoms and the nature of their content across cultures and within subcultures (e.g. Badcock, Clarke, & Morgan, 2018; Campbell et al., 2017; Jones & Luhrmann, 2016; Laroi et al., 2014). In fact, some would argue that what is viewed as psychosis or disorder in Western cultures may not be considered as pathological by another culture (see Kalra, Bhugra, & Shah, 2012).

Culture refers to ‘systems of knowledge, concepts, rules, practices that are learned and transmitted across generations’ (APA, 2013).

Jablensky et al. (1992) conducted the WHO collaborative study across 12 research centres in 10 countries. This seminal study showed that patients with schizophrenia living in developing nations have a better course, outcome, prognosis, and recovery than those in developed nations. Some possible reasons for this are better support and better acceptance or tolerance of (or less stigmatising attitudes towards) ‘odd’ (deviant) behaviour in these cultures. From a clinician perspective, understanding a person's explanatory model of psychosis is critical, in that one needs to understand the person's views about the onset, causes, and course of symptoms, its impact on the person, and what that person considers to be effective treatment (see Box 1.2 with Kleinman, Eisenberg, and Good's (1978) original eight questions concerning explanatory beliefs). In this way, the clinician can understand, and take into account, the patient's perspective and then assess the distance/commonality between their own perspective and that of their patient. Lloyd et al. (1998) developed a slightly more elaborated version of the explanatory model as created by Kleinman et al., 1978, termed the Short Explanatory Model Interview (SEMI). Although intended for use with patients with common mental disorders, the SEMI has also been used with patients with psychosis (e.g. Joy, Manoranjtham, Samuel, & Jacob, 2017 ; McCabe & Priebe, 2004). One emerging issue to note from this literature is that people may have multiple and seemingly contradictory explanatory models of their illness (Asher, Fekadu, & Hanlon, 2018).

Box 1.2

Eight Explanatory Model Questions

From Kleinman, A., Eisenberg, L., & Good, B. (1978). Culture, illness, and care: Clinical lessons from anthropologic and cross-cultural research. Annals of Internal Medicine, 88, 251–258. Copyright@1978 American College of Physicians. All Rights Reserved. Reprinted with the permission of American College of Physicians, Inc. The word ‘sickness’ has been replaced by the word ‘problem’.

Various clinical practice guidelines (see Table 1.1 for a brief overview of selected examples) and psychological society codes of ethics outline similar and common recommendations for the management of people with schizophrenia and related disorders, including a focus on cultural competencies. Distilled they are: that clinicians who are inexperienced should seek advice and supervision from those who are transculturally informed; the need for culturally sensitive assessment; the importance of understanding the explanatory models of the person (and their family and community); the need for psycho-education as to aetiology and treatment options, treatment expectations and adherence issues, and the need to involve working with community member organisations.

Table 1.1

a Professional psychologists are required to be familiar with the clinical practice guidelines relevant to their location and keep informed with any updates.

Regarding the two major nosologies of ICD and DSM, Paniagua (2018) compared the ICD-10 and DSM-5 on cultural variables. He found ICD-10 to be ‘mute regarding the need to consider such variables in this context of diagnosing people with mental disorders, whereas the DSM-5 does alert mental health practitioners that they should not make a diagnosis in this context without considering the cultural variables potentially affecting the assessment and diagnosis of such disorders.’ (p. 1). The release notes for ICD-11 schizophrenia now state that: ‘The categories in this grouping should not be used to classify the expression of ideas, beliefs, or behaviours that are culturally sanctioned’. https://icd.who.int/browse11/l-m/en#/http%3a%2f%2fid.who.int%2ficd%2fentity%2f405565289. A more detailed consideration of culture and psychosis is given in Chapter 4.

Psychosis as a Transdiagnostic Phenomenon

Psychotic symptoms are by no means only limited to patients diagnosed with schizophrenia. Given the difference in the prevalence of psychotic-like experiences in the general population (approximately 5%–10%; McGrath et al., 2015) compared to that of schizophrenia (approximately 1%), it is not surprising that many if not most people with psychotic-like symptoms will not be diagnosed with schizophrenia or even other schizophrenia-spectrum psychoses (e.g. schizoaffective disorder). Instead, they are more likely to be diagnosed with common mental disorders such as depression (unipolar or bipolar) or anxiety, or borderline personality disorder—especially in people who report hallucinations along with affective instability. However, the presence of psychotic symptoms even in the context of the more common disorders predicts greater symptom severity, poorer treatment response, and worse functioning (Varghese et al., 2009; Yung et al., 2005). Therefore, it is still crucial to identify and manage psychotic experiences even in nonpsychotic disorder help-seeking populations.

Conclusions on Diagnosis

Whilst characterising schizophrenia spectrum disorders as dimensions or categories is highly contested, it seems unlikely that in the near-to-medium future we will be able to dispense completely with categorical diagnostic systems such as ICD or DSM. We should consider diagnoses or syndromes as fuzzy descriptive prototypes: with repeated episodes the patient is likely to show a more consistent picture.

In support of a categorical view, McGorry et al., 2018, Kendler (2018), and Tyrer (2018) take a pragmatic approach emphasising utility; they argue that ultimately clinicians need to dichotomise people's problems whether the condition is dimensional or not (for commentaries see Jablensky, 2018; Tandon, 2016; Reed, 2018; Wittchen & Beesdo-Baum, 2018; Zachar, 2018). For example, blood pressure, temperature, and intelligence are all dimensional, but categories are formed in selecting people on the basis of cut-points for treatment or entry into services. Categories are also important for legal/medical purposes, e.g. insurance claims and for decisions in forensic psychiatry.

A diagnostic system has utility if it helps with treatment planning, prediction of course and outcomes, and identifying biological or social correlates.

Interestingly, Guloksuz and van Os (2018) also acknowledge the current problem of the utility of dimensional measures in clinical practice given clinical decisions are often dichotomous. With regard to the HiTOP model, Krueger et al. (2018) accept the ‘possibility that there are meaningful thresholds, beyond which social and occupational dysfunction becomes increasingly likely’ (p. 285). Finally, Caspi et al. (2014) acknowledge that it remains to be seen whether ‘p’ is ‘merely a statistical reductio ad absurdum or is it real and meaningful’ (p. 132).

Finally, it is important to understand that the structure of psychopathology is not the same as a diagnostic nosology—they are two very different things. Clinicians work from a ‘bottom-up’ approach. They are interested in the patient's presenting problem (signs and symptoms), the persistence of those signs and symptoms and their impact on the patient's functioning, but they are also concerned with what other signs and symptoms that patient has, as well as what they don’t have. Differential diagnosis is critical in excluding other conditions, e.g. a person with dementia may have psychotic phenomena as may people with substance-induced psychoses. Adhering to a nosology and the ability to make a correct and timely diagnosis can prevent serious consequences in the right context, such as professional neglect.

Clinical Staging Model of Psychosis

One prominent criticism of the current diagnostic system in psychiatry is the lack of biological disease markers to fully support the claim that mental disorders are, after all, no more than brain disorders. Although the role played by biological processes such as genetics and brain structure cannot be denied, the strength of evidence is not yet sufficient for definitive or clinically useful (e.g. diagnostic, staging, prognostic, or theranostic) biomarkers (for a review, see Prata, Mechelli, & Kapur, 2014; also Levine, Rabinowitz, Uher, & Kapur, 2015 for treatment response markers). As such, there is no clear analogy between the diagnostic tests used in general medicine and psychiatric diagnoses. More recently, however, inspired by staging models in oncology, the clinical staging model of psychosis and severe mood disorders (McGorry, Hickie, Yung, Pantelis, & Jackson, 2006; Wood, Yung, McGorry, & Pantelis, 2011) draws striking parallels with diseases encountered in other branches of medicine.

According to this heuristic model, the psychotic disorder spectrum has four main clinical stages, some with subcomponents (see Table 1.2). Each stage has recommended intervention strategies for its target population and may be linked to indicative biological and endophenotypic markers. For example, pathological changes in the brain's structure and function should be more severe in the later stages than they would otherwise be (if any) in the earlier stages, although in the current model no new markers are defined after a first episode of psychosis (i.e. progression into a fully disordered state).

Table 1.2