The addition of STEPPS in the treatment of patients with bipolar disorder and comorbid borderline personality features: a protocol for a randomized controlled trial

Bipolar disorder (BD) and borderline personality disorder (BPD) both are severe and chronic psychiatric disorders. Both disorders have overlapping symptoms, and current research shows that the presence of a BPD has an adverse effect on the course of BD. The limited research available shows an unfavorable illness course, a worse prognosis and response to medication, longer treatment duration, more frequent psychiatric admissions, higher drop-out, increased risk of substance abuse, increased risk of suicide, and more impairment of social and occupational functioning. However, there is no research available on the effect of specific psychotherapeutic treatment for this patients.

This paper presents the protocol of a RCT to investigate the presence of borderline personality features in patients treated for BD (study part 1) and the effectiveness of STEPPS (Systems Training for Emotional Predictability and Problem Solving) added to treatment as usual (TAU) for BD compared to TAU in patients with BD and comorbid borderline personality features (study part 2). STEPPS is a validated and effective intervention for BPD. The study population consists of patients treated for BD at specialized outpatient clinics for BD in the Netherlands. At first the prevalence of comorbid borderline personality features in outpatients with BD is investigated. Inclusion criteria for study part 2 is defined as having three or more of the DSM-IV-TR diagnostic criteria of BPD, including impulsivity and anger bursts. Primary outcomes will be the frequency and severity of manic and depressive recurrences as well as severity, course and burden of borderline personality features. Secondary outcomes will be quality of life, utilizing mental healthcare and psychopathologic symptoms not primarily related to BD or BPD. Assessment will be at baseline, at the end of the intervention, and at 12 and 18 months follow-up.

This will be the first randomized controlled trial of a specific intervention in patients with BD and comorbid BPD or borderline personality features. There are no recommendations in the guideline of treatment of bipolar disorders for patients with this complex comorbidity. We expect that a combined treatment aimed at mood disorder and emotion regulation will improve treatment outcomes for these patients.