Reward Circuits and Apathy in Schizophrenia: Neuroimaging and Treatment Strategies

Abstract

Approximately 50% of patients with schizophrenia shows deficits in motivation and initiation of goal-directed behavior, which are suggestive of reward system dysfunction. We conducted a meta-analysis of neuroimaging studies reporting on the neural correlates of reward processing and negative symptoms in schizophrenia. A significant mean weighted correlation was observerd, revealing deficits in activation of reward neurocircuitry. A more specific findings is comprised activation of the ventral striatum, involved in anticipation of reward, and structures that play a critical role in the ability to represent the value of outcomes and plans. In a study of VTA connectivity in the resting state in a large group of patients with schizophrenia, we found reduced connectivity with lateral prefrontal, temporal and parietal regions to be associated with higher degrees of apathy. Apathy belongs to the most debilitating symptoms of schizophrenia and represents a significant unmet need in its treatment. Quantitative integration of published findings suggests that treatment with noninvasive magnetic brain stimulation can improve negative symptoms. Previous PET-studies have shown that such stimulation may target circuits with dopaminergic innervation. A behavioral treatment approach that may also target reward-related circuits will also be discussed briefly. It can be concluded that recent results regarding reward and motivated behavior in schizophrenia have clinical implications and may help develop novel treatment strategies.

Disclosure of interest

AA received speaker fees from Lundbeck.