ABSTRACT. Background: Comorbidity between Attention-Deficit/Hyperactivity Disorder (ADHD) and depression and anxiety disorders in children and young to middle-aged adults has been well documented in the literature. Yet, it is still unknown whether this comorbidity persists into later life. The aim of this study is therefore to examine the comorbidity of anxiety and depressive symptoms among older adults with ADHD. This is examined both using cross-sectional and longitudinal data. Methods: Data were used from the Longitudinal Aging Study Amsterdam (LASA). Participants were examined in three measurement cycles, covering six years. They were asked about depressive and anxiety symptoms. To diagnose ADHD, the DIVA 2.0, a diagnostic interview was administered among a subsample (N=231, age 60-94). In addition to the ADHD diagnosis, the association between the sum score of ADHD symptoms and anxiety and depressive symptoms was examined. Data were analyzed by means of linear regression analyses and linear mixed models. Results: Both ADHD diagnosis and more ADHD symptoms were associated with more anxiety and depressive symptoms cross-sectionally as well as longitudinally. The longitudinal analyses showed that respondents with higher scores of ADHD symptoms reported an increase of depressive symptoms over six years whereas respondents with fewer ADHD symptoms remained stable. Limitations: The ADHD diagnosis is based on the DSM-IVcriteria, which were developed for children, and have not yet been validated in (older) adults. Conclusions: It appears that the association between ADHD and anxiety/depression remains in place with aging. This suggests that, in clinical practice, directing attention to both in concert may be fruitful.
