Relationship between theory of mind, impulsivity and cognitive functions in adult attention deficit and hyperactivity disorder

Objective: The aim of this study was to determine the relationship between neurocognitive functions, reading the mind in the eyes performance and impulsivity in adult attention deficit and hyperactivity disorder (ADHD) patients. Methods: Thirty subjects who had a diagnosis of ADHD and 30 control subjects aging between 18-65 years were included into the study. Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders Axis I (SCID I), Adult ADHD Self-Report Scale (ASRS), Barratt Impulsivity Scale (BIS), Reading the Mind in the Eyes Test (RMET) and neuropsychological tests (Digit Span Test, Auditory Consonant Trigram-ACT, Rey Verbal Learning Test, Visual Reproduction Test, Controlled Oral Word Association Test-COWAT and Stroop Task) were performed to all participants. Results: ASRS and Barratt Impulsivity Scale scores were significantly higher in ADHD group than the control group. No difference was found in RMET scores between the adult ADHD and the control groups. ACT, Stroop word reading mistake subscale and COWAT perseveration scores were found to be higher in ADHD group than the control group. Correlation analyses revealed that there was a significant and negative relationship between BIS inattention score and digit span forward test score; BIS motor impulsivity score and REY 1, REY 5 scores; BIS non-planning score and REY 5 score; BIS total score and digit span forward, REY 1, REY 5, REY 7 scores. Conclusion: Verbal memory functions are related with impulsivity in ADHD patients. Impulsivity, executive functions and theory of mind may be independent functions in patients with ADHD.