Executive functions in obsessive-compulsive disorder: State or trait deficits?

Objective: Despite the neuropsychology literature providing reliable evidence of impaired executive functions in obsessive-compulsive disorder (OCD), to date it has not been determined whether these deficits are trait-related (independent of symptomatology) or state-dependent (dependent on symptomatology). The current research examines the executive functions in OCD in a comprehensive manner and, for the first time, assesses the stability of these deficits over the developmental course of the disorder. Method: Using a cross-sectional design, Study 1 examined the executive functions (set shifting, inhibition, planning, verbal fluency and working memory) in 60 subjects (20 actively Symptomatic OCD, 20 Remitted OCD and 20 Panic Disorder). Using a longitudinal design, Study 2 reassessed a subsample of OCD subjects (participants in Study 1) once they reached remitted status. Results: Study 1 found that the OCD groups exhibited deficits in set shifting and inhibition relative to Panic Disorder controls; however, no deficits were observed in planning, verbal fluency or working memory. There were no differences found between the Symptomatic and Remitted OCD groups on any of the executive function measures. Study 2 found that the identified executive function deficits in individuals were stable over time and remained unchanged despite symptom remittance. Conclusion: Current results confirm the presence of specific executive function deficits in OCD, and indicate that these deficits are trait-like in nature.