[Duration effect on neuropsychological function and treatment response of OCD]

Because of inconsistency among previous reports that examined neuropsychological function and treatment response of OCD patients, we here consider the heterogeneity of OCD; for example: symptom-based clusters, degree of insight, age of onset, and comorbid diagnoses. In this study, we examined neuropsychological function and the treatment response of OCD patients. Thirty-two OCD patients participated in this study. We examined their clinical symptoms by Y-BOCS, MOCI and other scales, and examined their cognitive function with several neuropsychological tests including: WAIS-R, Stroop test, WCST, WMS-R and R-OCFT. We then randomly assigned them to three treatment packages including: behavior therapy, pharmacotherapy by fluvoxamine, and controlled therapy. The patients were divided into two groups by duration of illness: short to middle range group (Group S, n=17, 5.5+/-3.1 years), and long range group (Group L, n=15, 20.3+/-6.1 years). The mean age of Group L was higher than that of Group S (Group S: 30.6+/-9.7 years old, Group L: 36.1+/-6.2 years old). There was no significant group difference in sex ratio or number of years of education. The mean age of onset of Group L was significantly lower than that of Group S (Group S; 25.5+/-10.2 years old, Group L; 15.3+/-7.1 years old). The total Y-BOCS mean score and MOCI score showed no group differences. These two groups showed similar clinical characteristics such as the severity of OC symptom, OC subtypes, and comorbid depression. Group S, however, demonstrated significantly more obsession with the need for correction. Group L had significantly higher levels of anxiety and compulsion. There were also no group differences in the mean HDRS or STAI scores. As a result, compared to Group S, Group L showed significant attention deficit in the Stroop test and the WMS-R though other neuropsychological dysfunctions such as intellectual level, executive function, verbal memory, and nonverbal memory were found in this group. Concerning treatment response, Group L showed little improvement by pharmacotherapy. Behavior therapy brought significant improvement to all patients of both groups. Long duration of the illness might cause attention deficit and a lowered pharmaceutical response in OCD patients.