Neuropsychological deficits and treatment response in obsessive-compulsive disorder

Neuropsychological investigations of patients with obsessive-compulsive disorder (OCD) have shown inconsistent results. The present study tested the hypothesis that only a subgroup of patients with OCD actually shows neuropsychological deficits. Due to a stronger involvement of brain organic factors in the disorder, this subgroup was expected to be characterized by a poorer treatment response. 24 inpatients with OCD were examined before and after 9 weeks of behavior therapy. According to their decrease in severity of symptoms the patients were differentiated in 'Minor Responder' (n = 11) and 'Major Responder' (n = 13). Both groups did not differ in age, general intelligence, sex or handedness. The severity of symptoms before treatment was similar in both groups. Compared to normal controls (n = 13) matched for age, general intelligence, sex, and handedness, the group of 'Major Responders' did not show any neuropsychological deficits. The group of 'Minor Responders', however, was significantly impaired in three neuropsychological measures ('Paired-associate learning, visual', 'Verbal fluency, formal' and 'Verbal fluency, semantic') compared to normal controls before and also after treatment. These findings provide evidence for an effect of neuropsychological impairment on the treatment response in OCD.