Adult attention deficit/hyperactivity disorder among the prison inmates: An investigation of the executive function differences and comorbidity effects

Objective: Attention deficit/hyperactivity disorder (ADHD) is one of the most prevalent psychiatric disorders that often persist into adulthood. ADHD is associated with a high percentage of comorbid psychiatric disorders. Studies indicate that ADHD is prevalent among inmates. The aim of the present study was to evaluate the executive functions (EFs), that is, inhibition and working memory among inmates with and without ADHD after controlling for comorbidity effects. Method: Through stratified sampling method, 60 adult male inmates (30 with ADHD and 30 without ADHD) were selected on a voluntary basis and were matched for age and education. We compared the groups on measures of neuropsychological tests battery and self-rated comorbidities. Results: Prior to controlling for the effects of comorbid disorders, the ADHD and non-ADHD groups showed significant differences on several measures of attention; however, only the classic Stroop test interference score remained significant after controlling for the effect of the comorbid disorders. The group comparisons on the measures of memory remained unaffected from before to after controlling for the effects of the six comorbid disorders. Conclusions: Specific comorbid disorders may exacerbate the poor performance of prison inmates with ADHD on the tests of attention, but their performance on the tests of memory could remain unaffected by their comorbidity symptoms. We recommend replicating the study with ADHD participants with no criminal history.