The role of Executive Attention in the association between obsessive-compulsive symptoms and relapses in Major Depressive and Bipolar Disorder

INTRODUCTION: Major Depressive (MDD) and Bipolar Disorder (BD) are chronic relapsing condition in which mood episodes are interspersed with periods of euthymia. Impairments in Executive Attention (EA) are a trait characteristic of mood disorder that persists also during remission. Similarly prefrontal dysfunctions are crucial in the genesis and maintenance of Obsessive-Compulsive Symptoms (OCS), which are highly comorbid in both MDD and BD. OBJECTIVES: The aim of this study is to test a model in which deficits in EA mediate the relationship between the OCS and the relapse in a cohort of patients with MDD and BD. METHODS: Sixty-four euthymic subjects with BD and MDD performed the Attentional Network Task Revised (ANT-R), that gauges EA in a standard conflict task. Here we adopted a drift diffusion model to measure the task efficiency as the drift rate in incongruent trials. Patients also completed at baseline the YBOCS, a questionnaire that evaluate the severity of OCS. All the participants have been followed-up for up to 5 years and relapses have been recorded. RESULTS: The association between OCS and time in euthymia was fully mediated by the EA so that greater OCS were associated with poorer executive functions (beta=-0.341; p=0.006) that in turn predicted a sooner relapse (beta=0.349; p=0.005). This held true even when controlling for classic predictors of recurrence such as previous episode distance, the duration of illness and medications. CONCLUSIONS: Treatment targeting executive functions could hence be crucial in preventing relapses in subjects with mood disorders experiencing obsessive compulsive-symptoms. DISCLOSURE: No significant relationships.