Bipolar disorder (BD) is a complex and heterogeneous mood disorder defined by the occurrence of depressive, manic, hypomanic, and mixed episodes, divided by intervals of longer or shorter duration. DSM-IV-TR [
1] classification distinguishes bipolar I disorder (BD-I), bipolar II disorder (BD-II), bipolar disorder Not Otherwise Specified (BD-NOS), and cyclothymia. A study of the World Health Organization [
2] reported that BD is associated with significant functional impairment. There are considerable differences in the acute and prophylactic treatment response among patients with BD. Longitudinal studies show that despite treatment there are often recurrent episodes, residual symptoms, cognitive and psychosocial impairments and functional limitations [
3]. Many questions regarding the course and outcome of BD and factors that lead to an unfavorable outcome are still open to research. There is evidence that the presence of comorbid personality disorder (PD) has an unfavorable impact on the course of BD [
4]. Patients with BD and comorbid PD are more likely to be hospitalized, need more time to achieve symptomatic remission, have more chronic impairments in occupational and social functioning, are less compliant to medication, have greater levels of suicidality, and utilize more psychiatric services than patients with BD without PD [
5]. A review reported that BD patients have a significantly higher prevalence of PD than the general population [
6]. The prevalence of PD in patients with bipolar disorder is estimated between 30% and 40% [
7‐
10]. This concerns particularly personality disorders from the B and C clusters and in particular borderline personality disorder (BPD). There are considerable areas of clinical overlap between BD and BPD, especially mood instability [
11]. In a sample of 375 patients with a bipolar I or II disorder prevalence of BPD was estimated at 37.3% as screened by PDQ-4+, specified as 34,3% in 169 patients who were euthymic at the time of completing the PDQ-4+, 36,8% in 163 depressed patients, and 51.2% in 43 patients with current (hypo-) mania (personal communication R. Kupka: unpublished data from the Stanley Foundation Bipolar Network). Patients who meet diagnostic criteria for both disorders (BD and BPD) have more frequently a history of substance abuse [
12]. Furthermore there is evidence that the presence of comorbid PD has a negative impact on the course of BD, leading to more mixed episodes and depressive symptoms, a higher suicide risk, a worse therapeutic response, and less treatment adherence [
13]. Given the overlap in clinical presentation of BD and BPD, it has been suggested that there are shared underlying pathophysiological mechanisms [
14], [
15]. Only three publications report the effectiveness of treatment of BD with comorbid BPD. In a matched case–control study Swartz et al. [
16] compared patients who met diagnostic criteria for both BD and BPD with patients with BD without BPD. Both groups received pharmacotherapy and psychotherapy. The results suggest that treatment course may be longer in patients suffering from both BD and BPD. Preston et al. [
12] observed that dimensions of BPD improved significantly with lamotrigine treatment. There was a trend for comorbid bipolar patients to require a second psychoactive medication in addition to lamotrigine during extended treatment. Frankenburg and Zanarini [
17] compared in a placebo-controlled double-blind study the efficacy of divalproex sodium in the treatment of women with BPD and comorbid BD-II. They found that treatment with divalproex sodium significantly decreased irritability and anger, tempestuousness in relationships, and impulsive aggressiveness.
Currently little research exists on the effects of psychological treatments in patients with BD and comorbid borderline personality features or BPD. There are no specific recommendations included in the guidelines for the treatment of BD in this population (e.g., the Dutch guideline [
18]). There clearly is a need to develop new psychotherapies or evaluate existing psychological interventions to improve the course of BD and quality of life as well as reducing mental health care utilization in these patients. This study evaluates the addition of STEPPS (Systems Training for Emotional Predictability and Problem Solving) to treatment as usual (TAU) in patients with BD and comorbid BPD or borderline personality features as described in the inclusion criteria. STEPPS is a cognitive behavioral skills group treatment for BPD developed to improve their emotion regulation. The training consists of 20 weekly sessions of approximately 2,5 hours and has 4 parts: psycho-education, emotion regulation skills, behavioral skills, and emotion handling plan. Two trainers deliver the training. The group size is 8–12 patients. An uncontrolled pilot study presented an indication of the effectiveness of the STEPPS in BPD [
19]. A randomized trial [
20] showed that BPD patients treated with STEPPS compared with TAU showed larger reduction of BPD symptoms, more quality of life and less general psychological symptoms. All improvements were still significant after 6 months. In another randomized trial [
21] STEPPS plus TAU also led to greater improvements in impulsivity, negative affectivity, mood, and global functioning. STEPPS is included in the Dutch guidelines for treatment in BPD [
22]. The underlying assumption is that BPD is characterized by a defect in the individual’s internal ability to regulate emotional intensity. The aim of the training is to gain skills to manage emotions and behavior related problems. Friends and family members provide the “reinforcement team” and learn to reinforce and support newly learned skills of the patients (
http://www.steppsforbpd.com).
BPD can be conceptualized as a dimensional or spectrum disorder. Patients may suffer from significant symptoms of BPD without meeting the full diagnostic criteria defined by DSM-IV-TR. To increase the clinical relevance of the present study, both patients with BPD as well as those with borderline personality features are included. For this study patients with borderline personality features are included if they have three or more of the DSM-IV-TR diagnostic criteria, with the additional requirement that these include both impulsivity and anger bursts, since STEPPS training is specifically aimed at improving skills to regulate these symptoms.
The study described in this article will investigate the presence of borderline personality features in patients treated for BD (study part 1). Furthermore it will be investigated in a randomised controlled trial if a specific treatment (STEPPS combined with TAU) compared to TAU only will lead to better clinical outcomes as well as an increased quality of life and less care consumptions (study part 2).