ADHD in Adults: A Practical Guide to Evaluation and Management

By Craig B.H. Surman

ADHD in Adults: A Practical Guide to Evaluation and Management is the product of a unique collaboration of international specialists. This volume offers easy-to-read guidance, and includes checklists, rating scales and treatment planning tools. It was designed for a broad audience of caregivers working in diverse settings, including psychiatrists, social workers, primary care physicians, nurse specialists and psychologists. 

 

The authors are highly acclaimed clinicians, investigators and educators.  They offer step-by-step guidance for implementation of best practices, drawing from clinical research and their experience treating thousands of patients. They cover diagnosis, treatment planning, and state-of-the-art application of pharmacology, psychotherapy, skill-building, family system and environmental interventions – for both simple and complex cases. The scales and worksheets in this Guide were developed to efficiently facilitate assessment and management.

 

The Editor is an international leader in the field from the Clinical and Research Program in Adult ADHD at Massachusetts General Hospital (MGH) and Harvard Medical School, which has made pioneering and highly cited contributions to the understanding of ADHD. 

 

This Guide is a definitive, indispensable resource for all health providers who wish to optimize their approach to adult patients with ADHD.

 

• Language: English
• Publisher: Humana Press
• Release date: Nov 29, 2012
• ISBN: 9781627032483

Book preview

Craig B.H. Surman (ed.)Current Clinical PsychiatryADHD in Adults2013A Practical Guide to Evaluation and Management10.1007/978-1-62703-248-3_1© Springer Science+Business Media New York 2013

1. ADHD in Adults: A Clinical Concern

Philip Asherson¹  

(1)

MRC Social, Genetic, Developmental Psychiatry Centre, Institute of Psychiatry, King’s College London, De Crespigny Park, London, SE5 8AF, UK

Philip Asherson

Email: [e-mail]

Abstract

ADHD is an established disorder with widespread development of clinical services for children and adolescents. Cross-sectional and longitudinal studies also demonstrate the continuity of symptoms and impairments into adult life in many cases. This chapter provides an overview of the key clinical concerns and impact of ADHD on adults and emphasizes the importance of ADHD to adult psychopathology. The range of impairments is broad. At one end of the spectrum are high functioning individuals who cope well in many aspects of their lives, but struggle with symptoms such as chronic disorganization, restlessness, inability to relax, irritability, and difficulty sleeping. On the other hand, some individuals with ADHD are among the most dysfunctional in society, having considerable difficulties maintaining themselves in employment, completing simple everyday tasks, developing relationships, controlling their temper and being drawn into antisocial behavior, and drug and alcohol abuse. The severity of the symptoms of ADHD in some cases explains the frequent difficulty non-specialists can have in distinguishing ADHD from other mental health problems such as bipolar and personality disorders. The overall conclusion is that ADHD is a distinct condition that often has serious consequences for adults as well as children and adolescents. Because ADHD in adults is a common source of personal and societal suffering, because it is highly treatable, because it compounds other disorders, and because services for adults with ADHD are limited, ADHD deserves the full attention of those working in adult mental health.

Introduction

ADHD is an established disorder with widespread development of clinical services for children and adolescents. Many countries have access to either child and ­adolescent mental health or pediatric services with expertise in the diagnosis and treatment of ADHD. The disorder is estimated to affect around 5% of children g­lobally [1] who, depending on the severity of the condition and the co-occurrence of additional mental health or psychosocial problems, need medical, social, or ­educational interventions. Follow-up studies of children with ADHD find that around 15% retain the full diagnosis by the age of 25 years, and a further 50% are in partial remission with persistence of some symptoms associated with continued clinical and psychosocial impairments [2]. There is therefore a clear need for the development of effective diagnostic and treatment services for ADHD in adult life.

Definition and Etiology of ADHD

ADHD is a clinical syndrome defined in both the DSM-IV (attention deficit ­hyperactivity disorder) and the tenth edition of the International Classification of Diseases (hyperkinetic disorder) by the presence of high levels of hyperactive, impulsive, and inattentive behaviors when they begin during early childhood, are persistent over time, pervasive across situations, and lead to clinically significant impairments. Although the clinical syndrome is consistently associated with a wide range of social, environmental, neurobiological, and genetic variables, none of these are sufficiently sensitive or specific to predict the syndrome in clinical practice. The diagnosis therefore remains a descriptive one, based on the identification of a pattern of symptoms and behaviors that typically cluster together in the population and lead to a characteristic pattern of impairments and long-term outcomes.

Investigations into the etiology of ADHD suggest that the disorder is best ­conceptualized as the extreme and impairing tail of one or more quantitative traits that are found throughout the general population, resulting from multiple genetic and environmental risk factors [3]. This type of complex etiology is seen in a diverse range of common disorders such as cardiovascular disease, diabetes, asthma, ­anxiety, and depression, and in this sense ADHD should be seen as similar to many other common mental health and medical disorders. However, recent evidence also finds that rare chromosomal abnormalities called copy number variants (CNVs: duplication or deletions of sub-microscopic chromosomal regions) and severe early deprivation may confer moderate to large risks on development of the disorder in some cases [4, 5].

The Diagnostic Validity of ADHD in Adults

Many misconceptions surround the disorder and its treatment, particularly when ADHD persists into the adult years [6]. One common misconception, that ADHD does not persist into adulthood, is not supported by any of the follow-up studies of children and adolescents with ADHD. The disorder is found to persist into adulthood in the majority of cases, either as the full blown condition or with persistence of some symptoms associated with impairments [2]. Furthermore, worldwide prevalence ­studies of ADHD in adults estimate rates to be between 2.5 and 4.3% [7–9], ­indicating that this is one of the most common adult mental health conditions, alongside other common conditions such as anxiety and depression. As such a full understanding of ADHD is needed by all those working in adult mental health; and further research is needed to fully characterize the nature of ADHD in adults, quantify its contribution to adult mental health, and provide a better understanding of its relationship to co-occurring symptoms, syndromes, and disorders.

One concern that is often expressed is whether ADHD can be clearly delineated from other common mental health conditions. However, the disorder has a clearly defined pattern of symptoms and associated features. Delineation of the diagnostic construct from other disorders has been reviewed in detail and is based upon the following considerations [10].

1.

The symptoms that define ADHD are reliably identifiable, with test–retest ­reliabilities in the range of 70–80% for informant and self-ratings. There is strong evidence for clustering of the symptoms used to define ADHD in both clinical and population samples. The majority of studies support a two-factor model of hyperactivity-impulsivity and inattention in both children and adults. However recent studies suggest that ADHD is best perceived as having three main components consisting of an inattention factor, a hyperactivity-impulsivity factor, and a general factor that combines symptoms from both symptom domains [11].

2.

While ADHD symptoms cluster together and are separable from other symptom clusters, ADHD symptoms can often be identified in individuals with ­neurodevelopmental problems such as autism spectrum disorder and dyslexia. The overlap of these conditions has been shown to result from shared genetic influences [12, 13]. Other disorders commonly develop in people with ADHD including behavioral and emotional problems such as oppositional defiant ­disorder and conduct disorder during childhood; and antisocial personality ­disorder, substance abuse disorders (including alcohol and tobacco), anxiety and depression in adults. Overall, ADHD occurs in around 10–20% of people with common mental health problems according to epidemiological and clinical research [14–19]. Current research is focused on delineating the causal ­mechanisms involved in the development of comorbid mental health problems in people with ADHD, which include early prenatal risk factors, social exclusion, parenting factors, genetic risk factors, and common neurobiological pathways.

3.

Symptoms of ADHD appear to be on a continuum, in the same way that anxiety, depression, blood pressure, and weight are continuously distributed throughout the population [3]. Indeed, as with symptoms of anxiety and depression, ADHD symptoms are experienced by most people at times. The disorder is distinguished from the normal range by the number, severity, and persistence of symptoms, and their association with significant levels of impairment.

4.

ADHD symptoms have been tracked from childhood through adolescence and into adult life. They are relatively stable over time [20–23] with variable outcome, in which around two-thirds show persistence of some symptoms associated with clinically significant impairments [2]. In adults the profile may change with a relative persistence of inattention compared to hyperactivity-impulsivity [21, 24], although both sets of symptoms commonly persist and may create functional impairment in adults.

5.

The symptoms that define ADHD are associated with significant clinical and psychosocial problems throughout the lifespan. There are numerous studies on functional impairments in ADHD that clarify it is a disorder that impacts multiple domains [6]. These include subjective complaints of distress from symptoms of ADHD, difficulties coping with activities of daily life, problems with educational achievement that are not accounted for by general cognitive ability, impaired ­family and social relationships, and increased rates of antisocial behavior, drug abuse, and alcohol abuse. Difficulties with mood regulation are recognized as a core problem that is often associated with ADHD in adults and can be the main presenting complaint in some cases [25–27]. Common problems associated with ADHD in adults that are well documented include the development of anxiety and depression, unemployment, poor work performance, lower educational ­performance, and increased rates of traffic violations and accidents [14, 28–31]. High rates of ADHD within the criminal justice system [32] and drug and ­alcohol addiction services [33, 34] are a particular concern and suggest that we are not doing enough during childhood to prevent some of the more serious ­consequences of ADHD.

6.

There is strong evidence for both genetic and environmental influences in the etiology of ADHD. Family, twin, and adoption studies indicate it is a familial disorder which is predominantly influenced by genetic factors. Heritability of ADHD symptoms assessed in childhood and adolescence is estimated to be around 76% [35]. Twin studies using self-ratings in adults give lower estimates of genetic effects [36], in the order of 30–40%. However, recent twin studies from Sweden and the UK indicates that this is the result of rater effects, since similar high heritabilities to that seen in children and adolescents are seen when parent ratings are taken into account (references).

In keeping with all other psychiatric disorders at this time, no single measure has been found to be sufficiently predictive of the clinical disorder to be used as a ­diagnostic test. Genetic associations have been identified that passed genomewide levels of significance for two dopamine system genes in a meta-analysis of available data, namely, the dopamine D4 and D5 receptor genes [37]; and ADHD is consistently associated with both neurobiological [38, 39] and environmental measures [40–42]. However, when evaluating the many cognitive and neuroimaging measures associated with ADHD in adults [38, 43–46], it remains unclear which reflect shared causal processes (mainly shared genetic effects) and which might reflect key processes that mediate between the etiological factors and symptoms of ADHD [47].

An important advance has been the recent finding of rare chromosomal duplications and deletions (CNVs) in some children with ADHD compared to controls [4]. Within the normal range of general cognitive ability (IQ) such chromosomal defects were seen in around twice as many children with ADHD (14%) as unaffected controls (7%); who were in all other measured ways identical to ADHD children who did not carry genetic CNVs. More recent research has confirmed these findings [48]. The other important discovery was that some of the variants identified in ADHD involve genes that are also implicated in neurodevelopmental disorders such as autism and ­schizophrenia (see also [49]) confirming the neurodevelopmental origins of ADHD and providing direct molecular data for the observation of shared genetic risks between ADHD and autism spectrum disorders [50, 51].

7.

Treatment effects of stimulant medication (methylphenidate and amphetamines) and atomoxetine have been well documented in numerous controlled studies of ADHD in children and adults. These medications are very successful in reducing ADHD symptoms, with moderate to large effect sizes in the range of 0.4–1.2, with an associated impact on measures of global function and clinical impairment [10, 52, 53]. In adults improvements have been noted in other domains, particularly unstable or volatile moods [54–56]. The longest controlled trial of stimulants in adults to date shows treatment effects of medication over a 6-month period [57]; and in clinical practice we see continued benefits over many years. Non-pharmacological treatments have also been shown to be important with a growing evidence base for the complementary use of psychoeducation and ­cognitive behavioral approaches alongside pharmacological treatment [58].

Societal Burden of ADHD in Adulthood

The early onset and persistence of ADHD impairments into adult life leads to considerable economic as well as personal and social burdens on society. The economic burden in children was estimated to be around twice that of controls because of the higher rates of service use including inpatient, outpatient, and emergency services [59]. When the disorder persists into adulthood high economic costs are associated with employment problems (increased sickness leave, less productivity, and unemployment) as well as increased heath care costs [60–62]. The arguments for providing comprehensive clinical services for adults with ADHD therefore go beyond the individual care of people with mental health problems, to enhance national wealth (as well as health) by helping people with ADHD to contribute effectively to society. This is particularly important for ADHD because the availability of effective pharmacological and non-pharmacological treatments suggests that considerable savings can be made through effective treatments. Further work is now needed to evaluate the effectiveness of clinical interventions during childhood to improve the long-term negative outcomes of ADHD, as well as enhancing performance and reducing rates of psychiatric comorbidities.

The Need for Clinical Services for ADHD

National and international guidelines have been developed in several countries that recognize the need for clinical management of ADHD in adults and provide a consistent approach to the disorder and its clinical management. The strong consensus among experts within and between the different guidelines is striking in terms of the clinical criteria that are adopted, understanding of the impairments that are linked to ADHD in adults and the effects of both pharmacological and non-pharmacological treatments. As such, clinical guidelines, and efforts such as that of this text to foster their practical application, provide a consistent basis on which to establish much needed clinical services for this group of patients.

The current state of limited services for ADHD in adulthood can be devastating to individuals and their families. This will come as no surprise to the vast majority of child and adolescent psychiatrists and pediatricians, who have followed many patients with ADHD through initial diagnosis and treatment into the adolescent and adult years. They are well aware of the persistent course of the disorder into adult life and have been demanding proper transitional arrangements to be put in place for their patients for some years [65]. Furthermore, because of the highly familial nature of ADHD, with approximately 20% of first degree relatives of an ADHD proband also having ADHD [3, 66], they are well aware of the high proportion of parents of children with ADHD who present with similar problems. Even in communities with highly advanced medical services, ADHD often goes unrecognized and unaddressed.

Common Patterns of ADHD Presentation in Adulthood

1.

Patients diagnosed and treated in childhood or adolescence who require transition to adult mental health and/or primary care services for continued treatment and support.

2.

Adults who dropped out of treatment as adolescents now seeking further treatment.

3.

A large group of people with ADHD who were not diagnosed as children but present for the first time in adulthood.

Dropping out of treatment during adolescence is a recognized problem for chronic medical and mental health conditions. Adolescent services therefore need to find ways to engage with young adult patients and provide them with as much information and support as possible, whether they are compliant with medication and psychological treatment programs or not. Increased awareness of ADHD and treatment options for ADHD has also contributed to generational differences in the age at which ADHD is identified. For example in the UK very few children were diagnosed and treated for ADHD before the mid-1990s, leaving a large cohort of adults who never had the opportunity to be diagnosed during childhood. However, even now some forms of ADHD continue to be missed during childhood depending on the clinical presentation and expertise of schools and local services to recognize the disorder. For example, girls with primarily inattentive subtype and no comorbid behavioral problems may be thought to be slow learners rather than having a specific difficulty with ADHD, or boys with oppositional and conduct problems may be thought to have a primary behavioral problem with underlying ADHD being missed. Primary care physicians, mental health professionals and teachers therefore need to be aware of ADHD as a treatable ­condition and be sensitive to the different manifestations of the disorder.

Nosological Considerations and Comorbidity

Chapter 2 in this text addresses assessment of ADHD in adulthood, but ­particular characteristics of the clinical presentation merit exploration in this discussion of clinical validity. The diagnosis of ADHD in adults differs from the evaluation of adult onset mental health conditions in that it requires establishing longitudinal persistence of the condition since childhood. The symptoms are trait-like and abnormal compared to developmental comparison groups, but do not show the typical change from the ­pre-morbid state seen in most adult mental health disorders. While in children the ­diagnosis is traditionally based on parent and teacher descriptions of childhood ­behavior, many of which can be measured in terms of performance, ADHD also creates functional challenges that can only be evaluated subjectively. For ­example, individuals may ­complain of underperformance relative to their potential, or the extra time and effort that it takes to accomplish tasks. However, it is also important to recognize that there are distinctive characteristics of the mental state ­examination: symptoms such as multiple distracted thought process, mind on the go, forgetfulness, and feeling fidgety and restlessness. Thus while screening instruments, such as the World Health Organization (WHO) Adult ADHD Self Rating Scale [67] facilitates diagnosis, it is important to understand that clinical identification depends on familiarity with the basic syndrome and how it most commonly presents.

Several authors describe how ADHD symptoms manifest differently in childhood and adulthood [68–71]. Motor hyperactivity may be replaced by a subjective sense of restlessness, difficulty in relaxing or settling down, and dysphoria when inactive. Concentration deficits often persist in a lack of attention to detail, the need to re-read materials several times, forgetting activities and appointments, losing things and ­losing the thread of conversations. Thoughts are often unfocused and the mind on the go all the time. Mood changes can be rapid shifts into depression or excitability, irritability, and temper outbursts that interfere with personal relationships. Disorganization can also be prominent, where tasks are not completed, problem solving is lacking in strategy, and time management is particularly poor. Where present, the impulsivity of childhood may continue and leads to problems in teamwork, abrupt initiation, and termination of relationships and a tendency to make rapid and facile decisions without a full analysis of the situation. While most people experience such symptoms some of the time in their lives, the trait-like nature of ADHD symptoms means that individuals with ADHD experience these to an impairing degree most, if not all, of the time. Part of the disability that arises from ADHD is therefore the persistent (chronic and trait-like) nature of the symptoms which as a result have a deep and enduring impact on peoples’ lives.

Comorbidity Broadens Clinical Impact and Clinical Challenges

The challenge and importance of identifying and managing ADHD is underscored by its overlap with, co-occurrence with, and contribution to risk for comorbid conditions. Disorders for which there are considerable symptom overlaps include anxiety, depression, bipolar disorder, and personality disorder (particularly borderline or emotionally unstable personality traits). ADHD is a risk factor for ­development of all of these conditions or of exacerbation of their manifestation. As previously noted, increased rates of neurodevelopmental disorders also complicate clinical assessment and intervention, such as autism spectrum disorders and dyslexia and behavioral problems such as antisocial behavior and drug and alcohol abuse.

When considering the relationship of ADHD to comorbid symptoms there are three main categories to consider: (1) symptoms of ADHD that mimic other disorders; (2) symptoms of overlapping neurodevelopmental disorders that share etiological risk factors with ADHD; and (3) ADHD as a risk factor for the development of other co-occurring mental health conditions.

Symptoms of ADHD: Some symptoms represent alternative expressions of ADHD but can lead to mistaken diagnoses. Examples include symptoms of mood instability such as poor anger control, irritable and changeable moods which are commonly seen as associated features of ADHD; and which may respond to ­stimulants when treating adults with ADHD. Such symptoms overlap with broad concepts of bipolar disorder in addition to the emotional instability that is part of some personality disorder diagnoses [25]. Other symptoms often seen in ADHD, such as ceaseless distractible thought processes, avoidance of situations due to impatience, irritability when waiting in queues and situations requiring attention, or organization challenges while shopping or traveling, can give the impression of an anxiety disorder. Low self-esteem is another common problem that develops in people with ADHD and can lead to primary diagnoses of dysthymia or ­depression, especially when considered alongside other ADHD disturbances such as sleep problems (mainly initial insomnia and disrupted sleep patterns), distractibility, and unstable mood.

The separation from personality disorder is a particularly tricky nosological problems, since both ADHD and personality disorder are defined as trait-like conditions that start during childhood or adolescence and reflect the extremes of normal behavioral traits when they lead to significant impairment. Problems of classification arise because when the criteria for adult personality disorders were developed they did not take into account the potential role of neurodevelopmental disorders such as ADHD and autism spectrum disorders, which also give rise to trait-like symptoms and behavioral problems. The evolving nosology of personality will hopefully facilitate distinction between identifiable neurodevelopmental disorders and ‘temperamental’ or ‘character trait’ disorders. The need for such a change in approach by clinicians working with adults is particularly pertinent because of the availability of treatments known to be effective for ADHD. It is therefore important that patients who present with symptoms and behavioral disturbances of a chronic or trait-like nature (that do not represent changes from the pre-morbid mental state as in most adult onset disorders) are at least screened for ADHD so they can be referred for a full diagnostic assessment where this is indicated.

Neurodevelopmental disorders: Some symptoms seen in adults with ADHD represent co-occurring neurodevelopmental disorders. Research has shown that there are strong clinical and etiological associations between ADHD, other disorders of executive function, autism spectrum disorders, dyslexia, general learning difficulties, and disorders of coordination. Family and twin studies indicate that these result from shared genetic risk factors that are likely to represent the pleiotropic effects (multiple different effects) of genes. These comorbidities are important because they do not usually respond to the standard treatments for ADHD and are a source of continued impairment for some patients.

ADHD as a risk factor for development of co-occurring conditions: ADHD confers risk for the development of disorders such as antisocial behavior and substance use disorders in adulthood. While the risk factors that mediate the development of such behavioral problems include environmental risks such as maltreatment, there is now good evidence that genetic factors are also involved. Recent research found that the catechol-O-methyltransferase (COMT) val/val polymorphism, a genetic variant of the COMT gene that leads to low dopamine levels, is associated with the development of antisocial behavior and related phenotypes, but only in people with ADHD and not in controls [72]. Further work suggested that this association is mediated by poor development of social cognition [73]. These data suggest that ADHD itself can be viewed as an early risk factor that interacts with both genetic and environmental risks to influence the development of ­co-occurring behavioral disorders such as conduct disorder and antisocial personality disorder.

The reasons for increased risk of substance abuse in people with ADHD are complex and at least three basic mechanisms are likely to be involved. First we know that ADHD is associated with novelty seeking and risk-taking behaviors that are known risk factors for substance abuse disorders. This aspect of ADHD may reflect core cognitive deficits within the subcortical reward pathways and altered responses to rewards and reinforcers [74]. Secondly, having ADHD as a child is likely to increase exposure to psychosocial risk factors for substance abuse; such as poor social interactions, difficulties with education, being ­suspended or expelled from schools, and development of conduct problems. Finally, we know that patients report reductions in ADHD symptoms from the use of various substances, and it is not uncommon for adults with ADHD to report using either cannabis or alcohol to help them slow down and relax in the evenings or to get off to sleep. These different components to risk of substance abuse are important to understand because current evidence from clinical trials does not strongly support the efficacy of stimulants in the treatment of ADHD in substance abuse patients [52], suggesting that more work is required to fully understand individual SUD patients and provide a full range of treatments to target multiple underlying problems. Chapter 8 on common ­comorbidities in ADHD explores management of such presentations further.

Real-Life Impairments in Adults with ADHD

The most compelling evidence for the clinical importance of ADHD and its management comes from the experience of our patients. ADHD presents with a wide range of impairments from relatively high functioning individuals who nevertheless present with a range of symptoms and difficulties in completing certain types of tasks to those that are severely impaired and may have considerable difficulties in key aspects of their life. Some examples of the types of problems that people ­commonly present with are listed in Table 1.1. These examples are all from people who fulfilled the full diagnostic criteria for DSM-IV ADHD both as children and adults and for whom treatment with medication and psychoeducation had a ­considerable impact on improving the presenting complaint.

Table 1.1

Typical complaints responsive to treatment in adults with ADHD

The nature of the underlying symptoms that people with ADHD experience can also be seen by asking people to describe the type of changes in their mental state they experience when being treated for ADHD. The symptom response to ­pharmacological treatments such as methylphenidate and atomoxetine is highly characteristic and can usually be easily delineated by asking patients to compare the way they feel when they are on or off such medications. Examples of typical clinical presentations that have subsequently responded to treatment for ADHD, from patients attending my London clinic, are listed in Table 1.2.

Table 1.2

Typical response to ADHD pharmacotherapy in an adult with ADHD