Mindfulness-Based Cognitive Therapy (MBCT) and Cognitive Behavioral Therapy (CBT) for depression in patients with diabetes: a randomized controlled trial

Depression is a common comorbidity of diabetes, negatively affecting physical
performance, glycemic control, and adherence to medication, dietary, and
exercise recommendations. Modalities of psychotherapy can reduce depressive
symptoms in diabetes patients. Both mindfulness-based cognitive therapy (MBCT)
and cognitive behavioral therapy (CBT) are effective in medical settings in
attenuating adverse emotional and psychological components associated with
chronic disease. However, research about mindfulness is in its infancy and
proper designed randomized controlled trials are rare. Furthermore, more
reasearch is needed to assess the long-term effects of MBCT.

Primary Objective:
To assess immediate and long-term effects of Mindfulness-based Cognitive
Therapy (MBCT) and Cognitive Behavioral Therapy (CBT) in reducing depressive
symptoms in patients with diabetes. Regarding immediate effects, we expect that
both MBCT and CBT are more effective than a wait-list control condition in
reducing depressive symptoms in diabetes patients.
Secondary Objectives:
- To examine factors that moderate treatment effects of MBCT and CBT
- To examine factors that mediate treatment effects of MBCT and CBT
- To examine the role of treatment integrity and therapeutic relationship in
treatment effects and mediators of MBCT and CBT

A randomized wait-list control design.

Both treatment conditions comprise eight individual sessions led by a
psychologist and focusing on emotional, cognitive and behavioral aspects of
coping with depressive symptoms. Patients will also be asked to further
practice the skills they learn at home and in their daily lives.

The burden for patients consists of completing questionnaires on six occasions
(total time-costs: approximately 3 hours), eight 45-minute psychological
treatment sessions, and a telephone interview post treatment (20 minutes). The
patients will also be asked to engage in homework exercises during the course
of treatment (time-costs: about 30 minutes per day).
The therapy sessions will be recorded on video only if patients provide written
informed consent. The same is true for using any data from medical files of the
patients and using sampled blood to assess biochemical measures. For this, a
maximum of 3 ml extra blood will be sampled during routine blood sampling.

All patients receive psychological treatments in which techniques are used that
have proven to be effective for treating depression. To our knowledge, there
are no negative effects of these treatments. Risks of this study are considered
to be null, as patients are primarily asked to invest time and effort.