The association between CACNA1C rs1006737 A allele and blunted response bias may point to a genetic basis for anhedonia, which is a symptom common to affective and psychotic disorders.27,32,52, 53, 54 Although evidence suggests that anhedonia is a residual trait underlying euthymic bipolar disorder,54 it is less straightforward to align our findings with bipolar phenotypes associated with the hyperthymic state, as it is speculated that manic states could be associated with a potentiated rather than blunted response bias.32 Here, CACNA1C is linked to bipolar disorder.