A personality disorder is a severe and complex psychiatric illness. The borderline personality disorder (BPD) and the personality disorder not otherwise specified (NOS) both belong to the two most prevalent personality disorders. The lifetime prevalence of borderline personality disorders is estimated at 1-2% in the general population, whereas in patient samples the prevalence is approximate 10-20%. The personality disorder NOS has an estimated prevalence of 8-13% in patient samples [
1,
2].
Structured psychotherapy is recommended as the preferred treatment of personality disorders. Several studies report modest positive treatment results [
3-
9]. Psychotherapy contributes to higher quality of life, reduced psychopathology and destructive behaviour, and sustainable changes in personality.
A substantial group of patients, however, does not benefit from these psychotherapies [
10-
13]. Besides limitations in availability of these therapies, some patients do not meet the inclusion criteria or they drop out during treatment. Others need more psychosocial support for their many complex social problems. Most patients who do not benefit have a chronic and unstable course of illness with disruptive and destructive behaviour [
10,
13,
14]. They put a high demand on the health care services provided for rather long, but often discontinuous periods of time [
15]. These patients often receive community mental health care (often referred to as a team: CMHC team), mostly provided by (community) mental health nurses [
10,
14]. The treatment delivered by CMCH teams is, however, not standardized and highly unstructured [
16,
17].
Research indicates that especially nurses in particular experience caring for people with severe (borderline) personality disorders as highly stressful [
18-
21]. Strong emotional responses towards the patient arise frequently, particularly when the disruptive behaviour of the patient is unpredictable and difficult to understand. This contributes to condemnation of the patient by the nurse and a less empathic attitude. Ambivalent care seeking of these patients, shifting between dependency from and condemnation of professionals, can be explained out of their disorder and the irregular course of the therapeutic process. This same ambivalent care seeking, however, is difficult for care providers to accept and to cope with and it often leads to ineffective professional behaviour [
22,
23]. On the one hand, while balancing between autonomy and safety of the patient, nurses easily feel forced and responsible to protect the patient. Nurses may apply restrictive interventions to control the patient's destructive behaviour [
24-
26]. On the other hand, nurses may underestimate the needs and disabilities of their patients and perceive them as able but unwilling to change [
27,
28]. To keep the balance between playing a waiting game on the one hand, and being overly supportive and protective on the other hand is considered to be difficult with regard to these patients [
13,
27]. Studies reveal that patients and care providers set different priorities during treatment, including the specific needs of patients that require attention [
29-
33]. These, at times, conflicting priorities can cause miscommunication between patients and care providers and, hence, adversely affect outcomes of care [
29,
31].
As a response to these challenges, we developed a structured easily accessible intervention program for this subpopulation of patients, provided by (community) mental health nurses. For this intervention program we have adapted the principles of Collaborative Care (CC) [
34-
36]. Collaborative Care Programs originated in somatic health care to increase shared decision making and to enhance self management skills of chronic patients. Collaborative relationships come into existence when patients, their informal carers, and care providers have shared goals and mutual understanding of roles, expectations and responsibilities. As a consequence of more effective self management, patients report that their quality of life improves, because they feel they can better cope with problems derived from their disorder [
35,
36]. To date, Collaborative Care Programs (CCP) have proven to be effective for depressive and bipolar disorders [
37-
45].
Nurses have a prominent position in Collaborative Care Programs as they function as collaborative care managers. In this position they are responsible for optimal continuity and coordination of care. To optimize the continuity and coordination of care, intensive partnership working is needed within a Collaborative Care team (CCT). The CCT consists of the patient, his/her informal carer, the nurse, and the psychiatrist and/or psychologist. The CCT can optionally be expanded with others who possibly could contribute to effective treatment and care of the patient. The CCT lends support to the patient and it is in this team that crucial decisions regarding treatment will be made.
A Collaborative Care Program for patients with severe personality disorder has as to the best of our knowledge not yet been developed or tested. In this stage of intervention development, insights in both the feasibility and as well as the preliminary results of the intervention are needed. Therefore, we combine quantitative and qualitative data in a comparative multiple case study, which makes it possible to test the feasibility of the CCP in clinical practice, and also provides insight into the preliminary outcomes of CCP [
46,
47]. This study functions as a pre stage for a future RCT. The following research objectives are formulated:
(1). To describe the processes of the application of a Collaborative Care Program for patients with a severe borderline or NOS personality disorder in comparison with Care as Usual (CAU) from the perspective of patients, their informal carers and nurses;
(2). To describe the preliminary outcomes of the CCP in comparison with Care as Usual;
(3). To explain which characteristics of the CCP are indicative for the occurrence of positive or negative outcomes compared to CAU.