Reward learning deficits in Parkinson’s disease depend on depression

BackgroundDepression is one of the most common and debilitating non-motor symptoms of Parkinsons disease (PD). The neurocognitive mechanisms underlying depression in PD are unclear and treatment is often suboptimal.\n\nMethodsWe investigated the role of striatal dopamine in reversal learning from reward and punishment by combining a controlled medication withdrawal procedure with functional magnetic resonance imaging (fMRI) in 22 non-depressed PD patients and 19 PD patients with past or present PD-related depression.\n\nResultsPD patients with a PD-related depression (history) exhibited impaired reward versus punishment reversal learning as well as reduced reward versus punishment-related BO