title: Reward processing dysfunction in major depression, bipolar disorder and schizophrenia.
abstract: OBJECTIVE
  This article reviews the recent literature on reward processing dysfunction in major depression (MDD), bipolar disorder and schizophrenia, with a focus on approach motivation, reward learning and reward-based decision-making.
  
  
  RESULTS
  Emerging evidence indicates the presence of reward processing abnormalities across all three disorders, supporting a transdiagnostic approach. In particular, findings are consistent with a role of abnormal phasic striatal dopamine signaling, which is critical for reinforcement learning, efficient mobilization of effort to obtain reward and allocation of attention to reward-predictive cues. Specifically, reward-related striatal signaling appears blunted in MDD and the negative symptoms of schizophrenia, elevated in bipolar (hypo)mania, and contextually misallocated in the positive symptoms of psychosis. However, whether shared or distinct pathophysiological mechanisms contribute to abnormal striatal signaling across the three disorders remains unknown.
  
  
  CONCLUSIONS
  New evidence of reward processing abnormalities in MDD, bipolar disorder and schizophrenia has led to a greater understanding of the neural processes associated with symptomatology common across these conditions (e.g., anhedonia). Dissecting various subcomponents of reward processing that map onto partially different neurobiological pathways and investigating their dysregulation in different psychiatric disorders holds promise for developing more targeted, and hopefully efficacious treatment and intervention strategies.
authors.affiliation: McLean Hospital and Harvard Medical School, Belmont, Massachusetts, USA.
authors.forename: Alexis E
authors.initials: AE
authors.lastname: Whitton
authors.forename: Michael T
authors.initials: MT
authors.lastname: Treadway
authors.forename: Diego A
authors.initials: DA
authors.lastname: Pizzagalli
mesh_terms: D001714:Bipolar Disorder / Q000503:physiopathology / Q000523:psychology*; D003865:Major Depressive Disorder / Q000503:physiopathology / Q000523:psychology*; D006801:Humans; D009434:Neural Pathways / Q000502:physiology; D012201:Reward; D012559:Schizophrenia / Q000503:physiopathology; D012565:Schizophrenic Psychology; D015398:Signal Transduction / Q000502:physiology