The feasibility, acceptability and preliminary effectiveness of a combined lifestyle intervention for outpatients with a severe or chronic psychiatric illness (CHAPTER): a pilot controlled trial

There is an urgent need for new and low-coast approaches in the prevention and
treatment of mental disorders. Lifestyle interventions, targeted at changing
habits in multiple domains, might be such a new approach. Lifestyle
interventions are known to improve somatic health, which is important for
individuals with a psychiatric illness since unhealthy lifestyle choices and
somatic illness are common in this population leading to a life expectancy loss
of 10-20 years and high rates of somatic comorbidity. The effects of lifestyle
interventions in individuals with a psychiatric illness on somatic health and
mental health are promising, but effects on other domains of recovery are
unknown. Research is needed to answer questions on efficacy, feasibility and
acceptability of combined lifestyle interventions in outpatients with a
psychiatric disorder.

In preparation for an RCT we want to test a combined lifestyle intervention for
outpatients with chronic and/or severe mental health disorders in a feasibility
study. We want to evaluate the feasibility and acceptability of our
intervention and improve the intervention and research protocol using input
from participant and trainer experience.

Secondary, we want to explore the preliminary effects on lifestyle behavior and
the broad scope of health and recovery, with wellbeing as primary outcome.
Preliminary effects will be used to estimate the effect size for power
calculations regarding a future RCT.

This pilot aims to recruit 24 outpatients with a psychiatric disorder. The
participants will be randomized to receive a lifestyle intervention at onset of
the trial (intervention group) or to receive a delayed lifestyle intervention
when the trial is finished (control group). All participants will continue
their treatment as usual during the trial. Participants are screened on
inclusion criteria and health risks (somatic screening) before randomization.

Before and after the intervention both groups will be assessed on their (broad)
health and lifestyle behavior using questionnaires, somatic assessments, daily
diaries and actigraphy.

After the intervention, participants will be assessed on their experience with
and attition to the research protocol using an evaluation form and
semi-structured interviews. Additional questions on the intervention will be
asked to the interventiongroup. At three months post-intervention the
intervention group participants will be assessed on their long-term experiences
and needs.

The lifestyle intervention targets healthy changes of habits in one or more of
the following domains: nutrition, physical activity, relaxation, sleep,
spirituality and substance use. The intervention consists of 11 group sessions
of 3 hours spread over 23 weeks. The intervention consists of online and
face-to-face elements and is designed to be adjustable to be fully online if
needed.

No severe risks are expected from the intervention or study procedures.

The intervention is expected to be beneficial to the participant in multiple
domains of health and recovery.