Poor Sleep Quality Is Significantly Associated With Effort but Not Temporal Discounting of Monetary Rewards

Experimental sleep deprivation has been shown to differentially affect behavioral indices of effort and temporal discounting, 2 domains of reward processing often observed to be impaired in depression. Experimental sleep deprivation is phenomenologically different from sleep deprivation in everyday life (e.g., poor quality sleep or habitual short sleep duration). Thus, experimental findings may not explain how sleep disturbance impacts reward processing in everyday life. The present study examined associations of past-month self-reported typical sleep quality and duration among 325 young adults who completed behavioral tasks of effort and temporal discounting. Analyses accounted for the potential influence of self-reported mood symptoms and reward sensitivity. Results showed that poorer sleep quality, but not shorter sleep duration, was associated with less preference for high effort/high reward choices on the Effort Expenditure for Reward task (EEfRT) and was significant when accounting for depression and reward sensitivity, neither of which significantly predicted effort. Neither poorer sleep quality nor shorter sleep duration was significantly associated with a preference for smaller, more immediate reward on a delay discounting task. Findings suggest sleep quality, irrespective of total hours of sleep, may independently affect reward-relevant effort, which may have implications for the study and treatment of depression.