We need long-term strategies to reduce the risk of relapse or recurrence of depression. This is because 16% of the population are affected by major depressive disorder and at least 45% of them experience recurrences of the illness. People who experience these recurrences can typically have 7-8 depressive episodes over their entire life.
Various treatments for depression are available these days, but most of them are applied only when people are in the acute disease stage. The National Institute for Health and Clinical Excellence guidance (NICE, 2009) strongly recommends the continuing use of antidepressant medication in medication-responders. The period for using medication varies from at least 6 months to more than 2 years if the person presents a serious risk of recurrence. These recommendations are debated by the scientific community because there is a lack of evidence in this area.
NICE also recommends individual cognitive behavioural therapy and mindfulness-based cognitive therapy as preventive measures after remission from depression.
A recent meta-analysis published in the Journal of Affective Disorders (Biesheuvel-Leliefeld et al, 2015) investigates the effects of preventive psychological interventions, antidepressant medication (ADM) and treatment as usual (TAU) on reducing the risk of relapse or recurrence. The scope of this study was to include more types of psychological interventions than studies have previously, and they also included different forms for delivering therapy, including Internet-based therapy and booster sessions.
They hypothesised that different types of psychological interventions are equally effective, and not inferior to ADM or TAU.
25 studies out of 3,537 met all the inclusion criteria and were reviewed by the authors. The paper researching phase and selection criteria were provided by the authors and a thorough explication is provided for the statistical analysis conducted.
The inclusion criteria were: a randomised clinical trial, examining adult patients, with recurrent major depressive disorder, who were in remission at randomisation, were receiving a preventive psychological intervention aiming at reducing the risk of relapse or recurrence and had a comparison to a control condition.
The results are based on the analysis conducted on 25 studies with a total number of 2,055 patients that met the criteria.
- Although the authors did not find prevention trials based on therapies other than cognitive-behavioural therapy, mindfulness-based therapy and interpersonal therapy, as it was proposed in the beginning of the article, the results show that psychological interventions are superior to TAU when aiming to preventing relapse or recurrence over two years (RR=0.64, p < 0.001).
- They also found that psychological interventions are not inferior to ADM, showing that they are more effective than ADM in reducing the risk of relapse or a recurrence (RR=0.83, p < 0.017).
- Regarding their third hypothesis, different types of psychological interventions are equally effective, the authors found an effect size roughly similar. Sixteen trials included cognitive therapy, three trials included interpersonal therapy and six trials included mindfulness-based cognitive therapy.
In their discussion of the results the authors conclude that their review is the first one targeting the effect of all types of preventive psychological interventions on relapse or recurrence after remissions. They state that they included ADM and TAU as separate control groups, “which is new and very much awaited in the field”.
Besides showing that psychological interventions are superior to TAU and not inferior to ADM, they also revealed that the effectiveness of interventions aimed at preventive relapse or recurrence after remissions were enhanced when the patient had received an intervention whilst in the acute phase of the depression. Interventions received before included: psychological intervention, antidepressant medication or both combined.
This study has limitations, some of which are acknowledged by the authors of the study.
- In the beginning the authors stated that they wanted to include other types of psychological intervention which were not included in previous research. In the end they managed to include just interpersonal therapy, because the other two interventions (cognitive-behavioural therapy and mindfulness based cognitive therapy) were included before. Maybe we should wonder why?
- Then, as stated by the authors, the studies were different in their methodological design and had poor description of important factors as TAU.
- Publication bias is another limitation, and the roughly similar effect size of different types of psychological interventions was based just on the pooled results of the studies.
- Other limitations, not of this meta-analysis, but of the included trials, are represented by their low overall quality according to the GRADE evidence profile and the number of previous depressive episodes, which might have been under-reported. These limitations are also acknowledged by the authors.
Our understanding of the mechanisms that influence major depressive disorder and the risk of relapse or recurrence after remission has increased over the years, but we still need a lot of research in this area.
This review identifies some important aspects regarding psychological interventions and their applicability in preventing relapse or recurrence in depression, by analysing 25 published studies.
However, they did not succeed in comparing all types of therapy applied in depression, as they were proposing, due to a lack of studies which might investigate the effectiveness of interventions. This lack of evidence is not without reason and maybe unpublished data could help shed further light on this matter.
Biesheuvel-Leliefeld KEM, Kok GD, Bockting CLH, Cuijpers P, Hollon SD, van Marwijk HWJ, Smit F. (2015) Effectiveness of psychological interventions in preventing recurrence of depressive disorder: Meta-analysis and meta-regression. Journal of Affective Disorders, 174C, 400-410. 10.1016/j.jad.2014.12.016