A case series of sage: a new couple-based intervention for borderline personality disorder.

Background: Research suggests that interpersonal dysfunction may be central to borderline personality disorder (BPD), and that the relationships of people with BPD are particularly impaired. Further, the significant others of people with BPD exhibit elevated psychological problems but little access to mental healthcare. Despite this, most BPD interventions are delivered individually and do not routinely incorporate significant others. This manuscript presents the first case series of Sage, a 12-session manualized intervention for people with borderline personality disorder (BPD) and their intimate partners with three targets: a) BPD severity, b) relationship conflict, and c) intimate partner mental health.

Findings: Five couples of people with BPD with frequent suicidal/self-injurious behavior or high suicidal ideation and their intimate partners received Sage. Measures of Sage targets as well as tertiary outcomes were administered at pre-, mid-, and post-intervention. Four out of five dyads completed Sage, with high intervention satisfaction ratings. Improvements were generally demonstrated in BPD severity, suicidal ideation, and suicidal behavior/self-injury. Half of dyads exhibited improvements in conflict, and additional improvements in mental health outcomes for dyad members were demonstrated. One dyad exhibited poor outcomes and speculations regarding this are offered.

Conclusions: Findings provide proof of concept of Sage as an intervention that can improve BPD and other mental health outcomes in those with BPD and their intimate partners. Incorporating intimate partners into BPD treatment may optimize and expedite its outcomes. However, further testing is needed.

Trial registration: This project was pre-registered at Clinicaltrials.gov (Identifier: [NCT04737252]).