Comparing neuropsychological performance in adults with obsessive-compulsive disorder, attention-deficit hyperactivity disorder and healthy controls: An online study

Aims: Both obsessive-compulsive disorder (OCD) and adult attention deficit hyperactivity disorder (ADHD) are associated with neuropsychological underperformance, however few studies have directly compared neuropsychological performance between individuals with OCD versus those with ADHD. Additionally, previous studies have often included participants with comorbid conditions including depression, which may confound results. Method: Adults with existing diagnoses of OCD (n = 20) or ADHD (n = 71) without comorbid disorders, and controls (n = 63) completed online measures of symptoms of OCD, ADHD and depressive symptoms, and tasks assessing executive functions, working memory, inhibition and attention using an online cognitive testing platform. Analyses of variance and correlations were performed. Results: Overall cognitive performance did not significantly differ between the OCD, ADHD and control participants. OCD and ADHD symptoms were inversely related to neuropsychological performance on tasks assessing attention and visuospatial working memory respectively. However, test performance was more frequently correlated with depressive than OCD or ADHD symptoms. Conclusions: The results suggest that neuropsychological underperformance associated with OCD and ADHD may be related to the presence of comorbid disorders, such as depression, rather than disorder-specific phenomena, highlighting the importance of excluding participants with comorbid disorders in neuropsychological studies and targeting comorbidities in clinical contexts.