Depression is projected to become the single leading cause of disease burden by 2030. Its effect on our lives is enormous. Current treatments are considered to reduce only about one-third of the disease burden. It is obvious that prevention should take key priority in reducing the burden of depression. Strengthening protective factors (e.g. social, cognitive or problem-solving skills) or alleviating prodromal disease stages (e.g. reducing severity of depressive symptoms) have been investigated as potential strategies. Universal prevention (general public level), selective prevention ( high risk group approach), indicated prevention ( in prodrome stage) are the main three approaches to prevent a disorder.
Can depression be prevented by interventions?
Kim van Zoonen, Claudia Buntrock, David Daniel Ebert, Filip Smit, Charles F Reynolds , Aartjan TF Beekman and Pim Cuijpers report the results of meta analysis addressing the question. This is an update of their 2008 meta analysis. (Cuijpers et al 2008).
Methods: Comprehensive search ( for randomized trials, controlled trials, clinical trials where prevention was defined as reducing the incidence of new cases of MDD) and quality assessment was carried out to identify studies. Incidence rate ratio (IRR) for developing a depressive disorder in the intervention compared with the control group for each study was calculated.NNT i.e. how many people would have to receive a preventive intervention in order to prevent one new case of depression was also reported.
Search identified 4591 articles of which 235 met initial inclusion criteria.32 studies with 6214 participants met all inclusion criteria and were included in the analysis. Majority of studies (21) focused on preventing MDD, 9 studies aimed at postpartum depression (PMDD) and 4 dealt with mood mixed disorder (e.g. a combination of MDD, dysthymia and/or minor depression. CBT based interventions were the commonly employed intervention. Follow-up periods varied between 2 and 60 months.
IRR for all 34 comparisons from the 32 studies was 0.79 (95% CI 1⁄4 0.69–0.91; P 1⁄4 0.001). i.e. preventive interventions lowered the incidence of depression by 21%, compared with controls.Results did not suggest that indicated prevention (IRR = 0.74) was more effective than selective prevention (IRR 1=0.81). NNT appears high (20), but considering the impact of depression, this might be still of significant value. Analysis also suggest that the effects of the interventions are lower at longer follow-up periods. Sensitivity analyses revealed no differences between type of prevention (e.g. selective, indicated or universal) nor between type of intervention (e.g. CBT, interpersonal psychotherapy or other). Only two studies investigated universal prevention and those were therefore excluded from analysis.
Limitations: Follow up periods are short. Control conditions are care-as-usual or waiting-list ( i.e. not active comparators). publication bias is very much likely. Only psychological interventions were studied.Universal prevention might have a very different approach and yield very different results compared with selective and indicated prevention. However we do not have data to comment on this.
Summary of the article:
van Zoonen K, Buntrock C, Ebert DD, Smit F, Reynolds CF 3rd, Beekman AT, Cuijpers P. Int J Epidemiol. 2014 Apr;43(2):318-29.