The Developmental Trajectory of ADHD in Girls: Predictors and Associations of Symptom Change from Childhood to Young Adulthood

This dissertation presents an examination of the developmental course of symptoms of hyperactivity-impuslivity (HI) and inattention from childhood (Mdn age = 8.6 years) through young adulthood (Mdn age = 20.0 years) in an ethnically diverse sample of females diagnosed with childhood ADHD (n = 140) and a matched comparison group (n = 88). Latent growth curve models of caregiver-reported symptoms indicate that, over time, probands experienced a marked decline in all ADHD symptom domains (total, HI, and inattentive) yet continued to show significantly elevated symptom levels in young adulthood relative to the comparison sample (4 to 11 times their mean levels). Probands also experienced more maladaptive outcomes in adulthood, including internalizing symptomatology, functional impairments, and tobacco use. ADHD symptom severity in childhood and rate of symptom change over time each independently predicted these outcomes, with inattentive symptoms serving as more robust predictors of maladjustment than HI symptoms. Indeed, changes in inattentive symptoms across development exerted nearly double the effect of HI symptom change on internalizing symptoms and impairment in adulthood. Moreover, baseline inattentive symptoms and their rate of change were predictive of tobacco use, whereas HI symptoms were not. In addition, adult symptoms of ADHD were predicted by child psychopathology, paternal distress, and parental psychopathology, controlling for baseline ADHD status. These findings prospectively show that ADHD symptoms persist into young adulthood in women, and can be predicted by child and parent psychosocial and psychopathological variables. Overall, females with a childhood diagnosis of ADHD continue to show clinically significant impairments in crucial life domains into young adulthood. Findings underscore the relative importance of inattentive symptoms for females and stress the need to identify high-risk cases early in development