Cognitive functioning in adult psychiatric patients with and without attention-deficit/hyperactivity disorder.

ABSTRACT

INTRODUCTION: Studies of cognitive functioning in patients with attention-deficit/hyperactivity disorder (ADHD) have often used healthy comparison groups. The present study examines cognitive profiles, including general intellectual and executive functions, in a young adult psychiatric outpatient clientele with ADHD and evaluates whether their cognitive profiles can help differentiate them from patients with non-ADHD-associated psychiatric disorders. METHODS: The study group comprised 141 young adult psychiatric patients (age range 18-25 years) of whom 78 had ADHD. Comprehensive neuropsychological assessment included the Wechsler Adult Intelligence Scale, 4th version and subtests from Delis-Kaplan Executive Function System. Clinical psychiatric assessments and diagnostic evaluation were performed. RESULTS: The ADHD group (including all subtypes) had significantly lower verbal comprehension and full-scale intelligence quotient than the non-ADHD group. Tests measuring working memory or executive function did not separate those with and without ADHD. CONCLUSION: The results of our study suggest that, except for the need to establish overall cognitive performance level, the clinical implication of testing is small if the purpose is to "rule out" an ADHD diagnosis.