In sickness and in health: partner's physical and mental health predicts cortisol levels in couples.

Individuals in stable relationships tend to be healthier than those not in stable relationships. Despite this general positive influence of relationships on health, the mechanisms for the impact of relationship quality on health are not clear. Research has focused on many factors to explain this connection, including inter- and intra-couple dynamics of physiology and behavior. To address this issue, we examined the relationship between perceived health, depressive symptoms, and relationship quality on diurnal cortisol in 30 male/female romantic dyads (N = 60). Participants provided saliva samples on two weekdays to assess total cortisol output. Females' lower perceived physical health, lower relationship satisfaction, and higher depression scores were each related to higher cortisol output in their male partners. Males' physical health, relationship satisfaction, and depression scores were unrelated to females' cortisol output. Further, physical health, relationship satisfaction, and depression scores did not predict intra-individual cortisol levels for either sex. Measures of diurnal cortisol slope (DCS) were unrelated to psychosocial factors in males and females. Results provide further support for the interpersonal influence of partners' mental and physical health on physiological outcomes and suggest females may influence their male partners more than vice versa.