Romantic relationship distress is a common impairment among Veterans struggling with depression, posttraumatic stress disorder (PTSD), alcohol misuse, and suicide risk. In a study of Veterans who screened positive for the above concerns in primary care, 58% of partnered Veterans reported romantic relationship problems. Relationship problems are also a prominent risk factor for suicide, preceding 24% of Veteran suicide deaths and 50% for Veterans 18-35. Conversely, full participation in mutually supportive relationships confers protection against suicide. This suggests we may be able to offset risk by turning distressed relationships into protective partnerships. Unfortunately, the intensive formats of existing couple therapies result in couples discontinuing after 2-3 sessions or delaying treatment until they are close to breakup. This underscores the need for brief relationship support that is accessible through primary care mental health (PC-MHI). The Brief Relationship Checkup (BRC) is a three 30-minute session intervention to address relationship distress. BRC incorporates a combination of couple therapy and motivational interviewing techniques to encourage couples to make concrete commitments to improve their relationship. BRC demonstrates efficacy in reducing suicide risk factors such as relationship dysfunction and promoting protective factors such as mutual responsiveness to one another’s concerns, a core element of supportive relationships. Earlier Checkup programs have also been shown to increase individual and couple therapy engagement and reduce depressive symptoms. In an open label pilot trial, we found BRC was feasible and acceptable to Veterans screening positive on VHA mental health primary screens. We also found its highly structured framework could be learned by trainees without prior couple therapy experience. RESEARCH PLAN: We propose a pilot randomized controlled trial (RCT) of BRC administered to 72 couples to evaluate its ability to modify suicide risk/protective factors. Participants will be screened by phone to identify couples that are in distressed committed relationship where at least one partner is a Veteran (the “Target Veteran”) who screens positive on a primary care mental health screen for common suicide risk factors (i.e., suicide ideation, depression, PTSD, alcohol misuse). We will randomize couples to BRC or to three sessions of the current PC-MHI Co-Located Collaborative Care model (CCC) for the Veteran partner only. All participants will complete baseline, post-treatment, 3-month, and 6-month assessments. The study will provide the foundations for a larger clinical trial proposal through pursuit of the following research aims and hypotheses (H): AIM 1: Determine BRC’s efficacy in improving relationship factors related to suicide for both partners. H1a. Couples in BRC will report greater reductions in relationship dysfunction than those in CCC. H1b. Couples in BRC will report greater increases in mutual res...