Longer duration of amenorrhea is associated with lower delay discounting and less hedonic eating in girls and young women with low-weight eating disorders

Oligo-amenorrhea is common in low-weight eating disorders (LWEDs) and reflects cumulative suppression of the hypothalamic-pituitary-gonadal axis, leading to chronic or cumulative hypoestrogenism. Estrogen modulates mesolimbic dopaminergic signaling involved in reward behavior. Investigating amenorrhea-reward mechanisms in LWEDs is clinically relevant, as reduced reward responsiveness and associated altered decision-making may sustain disordered eating. We examined whether lifetime duration of amenorrhea is associated with reward-based decision-making and hedonic eating in females with LWEDs. We hypothesized that longer amenorrhea duration would correlate with reduced discounting of delayed rewards and lower hedonic food intake. Fifty-six females with LWEDs (age median[IQR] = 19.8[3.0] years) and 34 female healthy controls (HCs; 19.1[2.4] years) completed assessment of menstrual history, a monetary Delay Discounting Task, and a fed-state Cookie Taste Test (task to evaluate hedonic eating). Between-group differences were tested using Mann-Whitney U-tests. In the LWED group, partial Spearman correlations, adjusted for age and body mass index (BMI), examined associations of amenorrhea duration with discounting rate k and hedonic food intake. Participants with LWEDs reported a median of 16.5(22.6) missed menses since menarche. In LWEDs, longer amenorrhea duration correlated with shallower discounting (lower [ln]k; ρ = -0.40, p = 0.004) and lower hedonic eating task caloric intake (ρ = -0.34, p = 0.011); discounting and hedonic intake were not intercorrelated. These findings suggest that greater cumulative periods of hypogonadism may impact monetary reward sensitivity and hedonic eating in LWEDs, independent of age and BMI-defined illness severity. Prospective interventional studies should test whether modifying gonadal hormone exposure can alter delay discounting and pleasurable eating in this population.