Research suggests connections or links between the mental health of both partners in a romantic relationship because partners often report similar mental health problems, with implications for relationship functioning. The current study utilized the framework of interdependence theory to explore associations among intimacy development, as conceptualized by Erikson, relationship satisfaction, and depression in a sample of 128 same-sex male couples. In each couple, 1 partner was recruited first through active or passive outreach conducted online and in person. After completion of the online survey, the partner was then invited to send his partner a link to the study. The 256 male respondents (mean age = 32.6 years) all reported a U.S. residence and had an average relationship length of 5 years. Utilizing the Actor-Partner Interdependence Model, analyses indicated that participants’ intimacy development directly predicted their own relationship satisfaction (B = 1.84, p < .01) as well as their partner’s relationship satisfaction (B = 1.61, p < .01). Likewise, both the actor (B = −0.04, p < .01) and partner (B = −0.04, p < .05) effects of relationship satisfaction on depression were significant. Consistent with the interdependent concept of joint control, 3 indirect pathways linked Eriksonian intimacy to depression through relationship satisfaction. These findings suggest that individual development may become linked to mental health through pathways involving dyadic functioning. This pattern implies highly interconnected links between the intrapersonal and interpersonal, which have implications for mental health intervention with gay men in relationships.