Depression co-morbidity with ADHD

Abstract

Background:   ADHD symptoms typically arise during childhood, and often persist into adulthood, with childhood ADHD symptom severity significantly predicting persistence into adulthood. Moreover, ADHD is highly associated with comorbid conditions. Major depressive disorder (MDD) is one of the most common lifetime comorbidities associated with ADHD. MDD is a serious mood disorder that affects children’s and adolescents’ physical, emotional, and social-cognitive development. It is characterized by feelings of sadness and lack of interest or pleasure. ADHD and depression are individually associated with long-term negative outcomes, but their co-occurrence is associated with even greater levels of impairment and negative outcomes; this includes greater psychosocial difficulties and higher rates of hospitalization. It is important to not only understand the high occurrence of ADHD and depression together and how to differentiate between them, but also to examine the reasons for their coexistence. Multiple theories have emerged from this area of research. One set of theories suggests that ADHD and depressive disorders simultaneously arise due to the interplay of multiple “common causes,” or shared etiological factors (genetic, neurobiological, and environmental). Other theories assert that depression arises because of the secondary impairments associated with childhood ADHD symptoms, including social and academic difficulties.