CACNA1C and major depressive disorder: Previous research suggests that the CACNA1C rs1006737 risk variant is associated with heritable neuropsychiatric disorders.3,4,8,50 Reward responsiveness is potentially heritable43 and has been shown to be disrupted in patients with bipolar and unipolar depression.32, 33, 34, 35 Response bias is also blunted in remitted patients, suggesting that reward responsiveness may serve as trait marker.33 We demonstrate for the first time that the CACNA1C risk variant (rs1006737: A allele) modulates an individual's propensity to respond to reward, without disrupting general task discrimination ability.