This audio program explores the diagnostic precursors of bipolar disorder in offspring of bipolar parents, as well as a study examining the intergenerational transmission of anxiety, by looking at the children of twins, and another focusing on separation anxiety disorder in children and adults. Various diagnoses are characterized by impaired response inhibition, and a study is presented of how it relates to neural activation in adolescents with ADHD. Irritability also is a common phenotype, and a longitudinal study tracked the stability of genetic and environmental influences on irritability from childhood to young adulthood. Articles can be viewed online at ajp.psychiatryonline.org.