Little is known about the development and course of depressive symptoms through emerging adulthood among individuals with a childhood history of attention-deficit/hyperactivity disorder (ADHD). The aim of this study was to examine if a history of ADHD in childhood significantly predicted depressive symptoms during emerging adulthood (i.e., ages 18-25 years), including the initial level of depressive symptoms, continued levels of depressive symptoms at each age year, and the rate of change in depressive symptoms over time. 394 participants (205 with ADHD and 189 without ADHD; 348 males and 46 females) drawn from the Pittsburgh ADHD Longitudinal Study (PALS) completed annual self-ratings of depressive symptoms between the ages of 18 and 25 years. Childhood history of ADHD significantly predicted a higher initial level of depressive symptoms at age 18, and higher levels of depressive symptoms at every age year during emerging adulthood. ADHD did not significantly predict the rate of change in depressive symptoms from age 18 to age 25. Childhood history of ADHD remained a significant predictor of initial level of depressive symptoms at age 18 after controlling for comorbid psychiatric diagnoses, but not after controlling for concurrent ADHD symptoms and psychosocial impairment. Participants with childhood histories of ADHD experienced significantly higher levels of depressive symptoms than non-ADHD comparison participants by age 18 and continued to experience higher, although not increasing, levels of depressive symptoms through emerging adulthood. Clinical implications and directions for future research are discussed.
Keywords: ADHD; Depression; Emerging adulthood; Longitudinal outcome.