Circulating sex hormones and positive emotion: A new target in understanding risk for affective disorders

Sex differences in affective disorders suggest the role of circulating sex hormones in risk. Prior research has almost exclusively focused on distal symptom outcomes and negative emotions with mixed results. However, the emerging evidence of an etiological link between positive emotion responsivity and lifetime risk for affective disorders suggests that investigating the relationship between sex hormones and proximal, positive emotional reactivity needs further exploration. The present study investigated the relationship between estradiol and progesterone and implicit and explicit expression of positive emotion, in addition to negative emotion. Sixty-two female undergraduates completed questionnaires, passive drool collection, and idiographic interviews that elicited emotion in response to negative and positive emotion-inducing prompts. Implicit emotion was measured using spontaneous positive and negative word use and explicit emotion was based on ratings of affective experience. ANOVAs, including equivalence testing, revealed that there were no differences between naturally cycling women and hormonal birth control users, and groups were found to be equivalent on most outcome variables. Thus, groups were combined to test specific hormone-emotion associations. Hierarchical regression revealed significant inverse associations between the level of estradiol and both implicit positive word use and explicit reports of positive affect during the negative interview prompt and explicit positive affect in the positive prompt, even when controlling for depression symptoms. No significant main or interaction effects were detected for progesterone. The results of this initial study suggest a modulatory role for estradiol on positive affect which may influence emotion responsivity and have potential impacts on lifetime risk for affective disorders.