Preventing depression in adolescentsBMJ 2012; 345 doi: http://dx.doi.org/10.1136/bmj.e6720 (Published 08 October 2012) Cite this as: BMJ 2012;345:e6720
- Sally N Merry, associate professor, child and adolescent psychiatry ,
- Karolina Stasiak, research fellow
- 1Werry Centre for Child and Adolescent Mental Health, Department of Psychological Medicine, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
The individual and societal costs of depressive disorder have been well documented, and the arguments for depression prevention programmes are compelling.1 The prevalence of depression rises steeply in mid-adolescence, so schools are a logical place to deliver prevention programmes. Several studies have investigated the efficacy of interventions aimed at preventing depression in adolescents, and meta-analyses have provided encouraging results.2 However, many studies have had methodological difficulties, including lack of attention controls.
In a linked paper (doi:10.1136/bmj.e6058), Stallard and colleagues have reported the results of a large well conducted pragmatic randomised trial.3 They compared the resourceful adolescent programme—a group programme delivered in schools and based on cognitive behavioural therapy that has shown evidence of effect in universal samples of school students—with an attention control or usual classes.4 5 Facilitators were well trained, and the study was also appropriately powered and had excellent retention and follow-up rates. However, no demonstrable effect was seen, and the findings suggest that the intervention programme may actually have led to an increase in depressive symptoms. These findings are worrying, especially when meta-analyses have shown that depression prevention programmes are likely to be effective in adolescents.2 How can we interpret these results?
Could it be that depression prevention programmes, most of which are based on cognitive behavioural therapy, do not work after all? To date, few studies have compared the intervention with a placebo, and those that did tended not to show a significant effect.2 Because of the high placebo response rate found in studies of interventions for depression, placebo controlled studies—although challenging to undertake—are essential to determine whether the changes are due to a therapeutic effect, non-specific factors, or design artefacts.
Could it be that the resourceful adolescent programme is not as effective as other interventions that have been tested? This is unlikely because the reported effect sizes are similar to those seen in other studies.2 The intervention in Stallard and colleagues’ study was targeted at school students who self reported depressive symptoms. Two studies that seemed to be particularly effective used a two stage screening process, which ensured that participants had both a family history of depression and symptoms of depression above a certain threshold on self rating scales.6 7 Such an approach would be difficult to implement as a public health intervention, however. In addition, in one study 55% of participants reported having had a previous depressive episode, so that for these young people the intervention was effectively relapse prevention.7
Might the problem lie in implementation? Although there is evidence for the effectiveness of the resourceful adolescent programme,5 including from a randomised controlled trial that compared intervention with placebo,4 efforts to roll it out have foundered before.8 Ensuring fidelity nationally would probably be challenging for any of the programmes studied to date, nearly all of which involve group based delivery.
We agree with Stallard and colleagues that it would be premature to roll out depression prevention programmes on the basis of current evidence, and that this would risk wasting precious public health resources. In addition, the study has highlighted the potential to do harm, something that has not been adequately considered to date.
Where to next? The findings of more than 60 published studies suggest that depression could be reduced through prevention programmes based on cognitive behavioural therapy or interpersonal therapy. It is time for a new phase of research in which the most promising approaches are identified and tested against attention placebo conditions, or in head to head comparisons in studies designed with a view to practical implementation, with depressive episodes, not just depressive symptoms, as the outcome measure. An alternative approach would be to identify which parts of the programmes are effective, with a view to enhancing efficacy. We need to assess the potential for harm systematically. A collaborative international approach would help ensure that the large studies that are needed to show a difference in incidence of depressive disorder are undertaken.
Technology may provide some answers. Programmes delivered on computer, mobile phone, or the internet have several advantages.9 They can be delivered with fidelity and at low cost to large numbers of people, and they can have built in measures that make investigation of effectiveness easier. Comparison with an active control condition could be done relatively easily. Although, many parts of the world, including some regions within high income nations, have poor internet access, provision of basic computers through local schools, libraries, or churches—and access to high speed internet—is probably feasible in many communities, and mobile phones are becoming ubiquitous.10 It seems sensible to use innovation and technology, including social media, to reach younger people.
Furthermore, reducing the burden of depression in adolescents will require a broad framework approach. Several factors need to be investigated including the quality of early nurturing and the impact of parental depression, child trauma, child abuse, and poverty.11 12
Stallard and colleagues’ study is a timely reminder of the need for caution, and for careful systematic research to underpin efforts to reduce the effect of this costly disorder. The process of developing effective public health interventions is often long, involving an iterative process of testing and then refining interventions. We should expect no less for depression prevention programmes.
Cite this as: BMJ 2012;345:e6720
Competing interests: Both authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; both authors developed a computerised treatment for depression, SPARX, although neither author has any financial interest in SPARX.
Provenance and peer review: Commissioned; not externally peer reviewed.