B-Positive: Enhancing well-being in patients with bipolar disorder.

Bipolar disorder (BD) is characterized by recurrent manic or (hypo)manic
phases, alternating with (euthymic) states in which patients are relatively
symptom free. The prevalence of BD is estimated at 1,3% in the Netherlands.
Current treatment for BD in the euthymic phase often focuses on symptomatic and
functional recovery, but residual subthreshold depressive symptoms often remain
between episodes and form an important risk factor for recurrence. In order to
reach full recovery, it is important to strive for personal and complete mental
health recovery, which encompasses both the absence of mental illness and the
presence of well-being. One prominent field focusing on the improvement of
well-being, is positive psychology. Living to the Full is a positive psychology
intervention developed at the University of Twente, which aims to increase
well-being. The current study therefore aims to assess the effectiveness of
Living to the Full for people with bipolar disorder in the euthymic phase.

The primary objective of this study is to evaluate whether the eight-week
multicomponent well-being intervention 'This is your life' as an adjunct to
usual care (CAU) offered to BD patients in the euthymic phase, is effective in
the short and long term in improving well-being.

Secondary objectives of the study are:
(1) To study whether the intervention This is your life in addition to CAU is
more effective in the short and long term in improving outcomes of personal
recovery, social role participation, and symptoms of depression, anxiety and
mania than CAU only.
(2) To find out whether This is your life is more effective in reducing
relapses into depressive, (hypo)manic or mixed episodes in euthymic patients
with BD in the long term than CAU only.
(3) To explore possible working mechanisms for intervention effects of This is
your Life, including positive emotions, positive emotion regulation,
self-compassion and positive relations.
(4) To evaluate the cost-effectiveness of the intervention This is your life in
addition to CAU for the treatment of euthymic patients with BD compared to CAU
only.

This study concerns a pragmatic randomized non-blinded multicenter trial. The
intervention group receives the intervention 'This is your Life' in addition to
CAU. The control group receives CAU only. Measurements take place at baseline
(T0), mid-treatment (T1), post-intervention (T2) and follow-up 6 (T3) and 12
(T4) months from baseline.

We aim to adapt the multi-component positive psychology intervention 'This is
your Life' as group intervention for BD. 'This is your Life' has been developed
at the University of Twente and is based on empirically validated theories
within positive psychology, including Seligman*s well-being theory (PERMA
model) and Ryff*s Theory of psychological well-being. 'This is your Life'
focuses on six components in positive psychology: (1) positive emotions, (2)
discovering and using personal strengths, (3) optimism and hope, (4)
self-compassion, (5) resilience and post-traumatic growth and (6) positive
relationships. The intervention consists of 8 meets of 2 hours and takes place
in groups of 10 patients.
From September 2020, the intervention will be delivered online. This will not
affect the intensity or content of the intervention. Also, the intervention
will still be given by two trained therapists from the participating treatment
centers.

The burden associated with participation in the study is relatively low.
Participation is free and can be stopped at any time and without explanation,
if the patient wishes so, by telling the principal investigator. We ask
participants to fill out questionnaires at five measurement points. At each
measurement point, this will take approximately 36 minutes on average at each
measurement point. No relevant burden is expected from filling out the
questionnaires, which are all commonly used and well-validated. During the
sessions, participants are asked to try particular positive psychological
exercises. Moreover, part of the group intervention is to talk about personal
experiences. Additionally, part of the intervention are homework exercises.
Since the extent to which these exercises are performed is voluntary, we do not
expect a high burden from the homework exercises.
No great risks are expected from participation in the intervention. 'This is
your Life' has been carried out several times by the University of Twente and
no negative events have occurred. However, since the effect of positive
psychology interventions for individuals with BD is relatively unclear, the
consequences for participants in the intervention group are not fully
predictable. It cannot be ruled out that interventions enhancing positive
behaviours, cognitions or emotions such as 'This is your life' might heighten
the risk for a manic phase. Since the intervention is carried out in treatment
centers specialized on bipolar disorder, possible participants excluded due to
severe symptoms of depression or mania, will find themselves in a protective
environment where professionals are able to take care of them. Also, certain
parts of the intervention might be confronting for participants by reviving
certain cognitions or behaviours they usually try to avoid (e.g. memories).
From September 2020, the intervention will be given online. However, we do not
expect any additional risks from this change in delivery mode (see also point
E9).