Motivational deficits and anhedonia in schizophrenia: insights from behavioral activation and behavioral inhibition systems

PURPOSE: Schizophrenia is a disorder characterized by significant motivational deficits, including anhedonia, that impair daily functioning. Approach and avoidance behaviors are regulated by two basic motivation systems: the Behavioral Inhibition System (BIS) and the Behavioral Activation System (BAS). Based on Gray's Reinforcement Sensitivity Theory, this study examined the relationships among BIS/BAS activity, depressive symptoms, and anhedonia in individuals with schizophrenia compared to healthy controls. METHODS: Sixty-one patients with schizophrenia (SZ) and 62 healthy participants participated in the study. Positive and Negative Syndrome Scale, Beck Depression Inventory, Calgary Depression Scale, BIS/BAS Scale, and physical, social, and chemosensory anhedonia scales were administered to the participants. This cross-sectional, between-groups study compared SZ and healthy controls to examine the associations among BIS/BAS activity, depressive symptoms, and anhedonia. T-test, Logistic regression, and regression analyses were performed. RESULTS: Logistic regression analyses determined that BAS activity and anhedonia significantly predicted being in the patient group. It revealed motivational deficits in schizophrenia compared to healthy subjects. Patients with schizophrenia showed reduced BAS activity associated with impaired reward sensitivity and goal-directed behavior. However, no differences in BIS activity were found. While BAS activity and depressive symptoms were found to be predictors of all subscales of anhedonia in healthy controls, they were only found to be predictive of physical anhedonia in schizophrenia. CONCLUSION: These results suggest that anhedonia in SZ results from deficits in anticipatory pleasure and reward processing, independent of mood-related mechanisms. It suggests that different mechanisms may underlie anhedonia. Future studies should investigate BAS dysregulation in SZ, including cognitive-behavioral therapies and pharmacological strategies that target dopaminergic pathways.