Background: Anhedonia is a cardinal feature of major depression and is hypothesized to be driven by low motivation, in particular blunted reward sensitivity. It has been suggested to be a marker that represents a genetic predisposition to this disorder. However, little is known about the mechanisms underlying this heightened risk in unaffected rst-degree relatives of patients with major depression. We previously demonstrated abnormal reward biases in acutely depressed patients. The present study aimed to ex-amine the development of reward bias in rst-degree relatives of patients with major depression. Methods: Forty-seven rst-degree relatives of patients with major depression (26 females, age 18–52) and 60 healthy controls with no family history of depression (34 females, age 21–48) were recruited. Aprobabilistically rewarded dif cult visual discrimination task, in which participants were instructed about the contingencies, was used to assess blunted reward sensitivity. A response bias towards the more frequently rewarded stimulus (termed “reward bias”) was the primary outcome variable in this study. Participants also completed self-reported measures of anhedonia and depressive symptoms. Results: Compared with the control group, relatives of patients with major depression with sub-clinical depressive symptoms displayed a blunted reward bias. Relatives without symptoms displayed largely intact motivational processing on both self-report and experimental measures. The degree of anhedonia was associated with attenuated reward bias in rst-degree relatives of patients with major depression, especially in those with sub-clinical symptoms. Limitations: The study did not include a depressed patient group, which restricted our ability to interpret the observed group differences. Conclusions: Blunted reward sensitivity may be largely manifested in a subgroup of relatives with high levels of depressive symptoms.