Are there reliable changes in memory and executive functions after cognitive behavioural therapy in patients with obsessive-compulsive disorder?

Introduction. Patients with obsessive-compulsive disorder (OCD) have impaired memory and executive functions, but it is unclear whether these functions improve after cognitive behavioural therapy (CBT) of OCD symptoms. The primary aim of this study was to investigate whether memory and executive functions change after CBT in patients with OCD. Methods. We assessed 39 patients with OCD before and after CBT with neuropsychological tests of memory and executive functions. To correct for practice effects, 39 healthy controls (HCs) were assessed at two parallel time intervals with the neuropsychological tests. Results. There were no changes in memory and executive functions after CBT in patients with OCD when results were corrected for practice effects. Patients performed worse on a test of visuospatial memory and organisational skills (Rey complex figure test [RCFT]) compared to HCs both before and after CBT (ps = .002-.036). Conclusions. The finding of persistent poor RCFT performances indicates that patients with OCD have impaired visuospatial memory and organisational skills that may be trait-related rather than state-dependent. These impairments may need to be considered in treatment. Our findings underline the importance of correcting for practice effects when investigating changes in cognitive functions.