Smoking is associated with lower performance in WAIS-R Block Design scores in adults with ADHD

Adults with attention-deficit/hyperactivity disorder (ADHD) are predisposed to smoking, but the neuropsychological correlates of this association have not been elucidated so far. The present study evaluates possible associations between cognitive performance and smoking and other comorbidities in adults with ADHD. Two hundred and sixty-four (264) patients were evaluated in the adult ADHD outpatient clinic of the Hospital de Clínicas de Porto Alegre. The diagnoses were based on the DSM-IV criteria and interviews were performed with the Portuguese version of K-SADS-E for ADHD and oppositional-defiant disorder. Axis I psychiatric comorbidities were evaluated with the SCID-IV and the cognitive performance with the Vocabulary and Block Design subtests of the Wechsler Adult Intelligence Scale-Revised (WAIS-R). The evaluation of the influence of the WAIS-R scores on each dependent variable was performed with logistic regression analyses. Lower scores in the Block Design subtest of WAIS-R were associated with smoking and the presence of anxiety disorder. These results suggest that a subgroup of ADHD patients with lower Block Design subtest scores may be at increased risk of smoking as a cognitive enhancement. Our findings also confirmed the previously suggested association between anxiety and lower Block Design scores.