Should we be offering mindfulness-based cognitive therapy to all patients with residual depressive symptoms?

Mindfulness-based cognitive therapy (MBCT) is a group training approach that aims to prevent relapse and recurrence of depression. It combines mindfulness techniques with cognitive therapy and research shows that it is effective at reducing depressive symptoms as well as preventing relapse.

The NICE depression guideline recommends that MBCT is offered to people who have experienced 3 or more previous episodes of depression as an intervention to prevent relapse:

Psychological interventions for relapse prevention

1.9.1.8 People with depression who are considered to be at significant risk of relapse (including those who have relapsed despite antidepressant treatment or who are unable or choose not to continue antidepressant treatment) or who have residual symptoms, should be offered one of the following psychological interventions:

individual CBT for people who have relapsed despite antidepressant medication and for people with a significant history of depression and residual symptoms despite treatment
mindfulness-based cognitive therapy for people who are currently well but have experienced three or more previous episodes of depression.

1.9.1.10 Mindfulness-based cognitive therapy should normally be delivered in groups of 8 to 15 participants and consist of weekly 2-hour meetings over 8 weeks and four follow-up sessions in the 12 months after the end of treatment.

[Taken from p.37 of the NICE depression guideline]

This advice is based on the original MBCT trials that were conducted around a decade ago. However, this recommendation has now been brought into question by a new randomised controlled trial (RCT) published this week in the British Journal of Psychiatry.

A group of researchers from Maastricht University in the Netherlands conducted an open label RCT that aimed to find out whether the effect of MBCT on residual depressive symptoms is contingent on the number of previous depressive episodes.

They recruited 130 currently non-depressed adults:

59 had 3 or more prior major depressive episodes (hereafter: ‘3+’)
71 had 1-2 prior episodes of depression (hereafter: ‘2–’)

A baseline assessment was carried out and both groups had similar demographic and clinical characteristics. The 3+ group seemed to be more affected by their depression (e.g. they were less likely to be working and had more comorbidity) which is probably representative of real-life.

Trial participants were randomly allocated to one of two interventions:

Usual treatment (if any; waiting list control condition)
8 weeks of MBCT in addition to their usual treatment (if any). MBCT groups were delivered by trained staff, run weekly, lasted for around 2.5 hours and involved 10-15 people. Sessions included guided meditation, exercises and discussion. Participants also took home CDs with exercises and were assigned 30-60 min of daily homework.

The researchers used two well respected measurement scales to assess depressive symptoms:

Hamilton Rating Scale for Depression (HRSD)
Inventory of Depressive Symptoms (self-rating, IDS)

Here’s what they found:

MBCT was superior to the control condition across subgroups
MBCT was effective at reducing residual depressive symptoms after 8 weeks, 6 months and 12 months
This improvement was seen in the 3+ and 2- groups, showing that MBCT is equally as effective in both groups of patients

The authors stated that:

It may be argued that individuals with persistent and harmful residual depressive symptoms originating from a first or second episode should not be denied access to [MBCT] treatment that can improve their quality of life and possibly decrease their risk of relapse/recurrence.

This well-conducted RCT has sufficient power to provide a reliable answer to the targeted question. It also has a larger sample size than the original studies conducted a few years ago, upon which NICE have based their guidance.

Clearly the trial is not without limitations:

The comparison with controls was conducted immediately post-treatment (8 weeks), but not at 6 or 12 months
The included patients were a heterogeneous group, which made detailed comparisons difficult
Therapists were blinded to the depressive history of participants, but the open-label trial design meant that the patients were a self-selecting sample, which can sometimes lead to selection bias
Repeating this kind of study in a more real-world setting would likely provide more evidence to support the use of MBCT for people with only 1 or 2 previous depressive episodes