Self-help interventions for depressive disorders and depressive symptoms: a systematic review

Annals of General Psychiatry Self-help interventions for depressive disorders and depressive symptoms: a systematic review Amy J Morgan and Anthony F Jorm* 0 Address: Orygen Youth Health Research Centre, Department of Psychiatry, University of Melbourne , Parkville , Australia Background: Research suggests that depressive disorders exist on a continuum, with subthreshold symptoms causing considerable population burden and increasing individual risk of developing major depressive disorder. An alternative strategy to professional treatment of subthreshold depression is population promotion of effective self-help interventions that can be easily applied by an individual without professional guidance. The evidence for self-help interventions for depressive symptoms is reviewed in the present work, with the aim of identifying promising interventions that could inform future health promotion campaigns or stimulate further research. Methods: A literature search for randomised controlled trials investigating self-help interventions for depressive disorders or depressive symptoms was performed using PubMed, PsycINFO and the Cochrane Database of Systematic Reviews. Reference lists and citations of included studies were also checked. Studies were grouped into those involving participants with depressive disorders or a high level of depressive symptoms, or non-clinically depressed participants not selected for depression. A number of exclusion criteria were applied, including trials with small sample sizes and where the intervention was adjunctive to antidepressants or psychotherapy. Results: The majority of interventions searched had no relevant evidence to review. Of the 38 interventions reviewed, the ones with the best evidence of efficacy in depressive disorders were Sadenosylmethionine, St John's wort, bibliotherapy, computerised interventions, distraction, relaxation training, exercise, pleasant activities, sleep deprivation, and light therapy. A number of other interventions showed promise but had received less research attention. Research in non-clinical samples indicated immediate beneficial effects on depressed mood for distraction, exercise, humour, music, negative air ionisation, and singing; while potential for helpful longer-term effects was found for autogenic training, light therapy, omega 3 fatty acids, pets, and prayer. Many of the trials were poor quality and may not generalise to self-help without professional guidance. Conclusion: A number of self-help interventions have promising evidence for reducing subthreshold depressive symptoms. Other forms of evidence such as expert consensus may be more appropriate for interventions that are not feasible to evaluate in randomised controlled trials. There needs to be evaluation of whether promotion to the public of effective self-help strategies for subthreshold depressive symptoms could delay or prevent onset of depressive illness, reduce functional impairment, and prevent progression to other undesirable outcomes such as harmful use of substances. - Background Data from recent epidemiological studies suggest that depressive disorders exist on a continuum, rather than in separate categories [1,2]. As a consequence, research has begun to accumulate on the clinical relevance and public health significance of depressive symptoms not meeting diagnostic criteria, variously labelled subthreshold, subclinical, subsyndromal, mild, or minor depression. Here, we use the term subthreshold depression. Subthreshold depression is prevalent [3], increases the risk of developing major depressive disorder [4], and has considerable economic costs [5]. At the individual level, disability from subthreshold depression is lower than for depressive disorders; however, the burden of disability for the population as a whole is substantial for subthreshold depression because of its greater prevalence [6]. Given that unipolar depressive disorders were the leading cause of disability burden globally in 2001 [7], depressive symptoms falling short of a disorder are of major public health significance. Several trials have investigated treatments for milder depressive states, with some success [3,8]. However these treatments, which include antidepressant medication and brief psychotherapy, involve the participation of health professionals. An approach that does not further burden clinical resources is preferable, as there is already a large group of people with major depression who do not receive treatment [9], and treating these people deserves priority over those with subthreshold symptoms. An alternative approach is self-help that can be applied by the individuals affected without the need for professional guidance. Self-help approaches for depression are commonly used, particularly for milder forms of depression [10,11], and are perceived as helpful by the public [12]. However, some self-help methods in common use are probably selfdefeating (for example, substance use). If effective informal self-help methods could be identified, they could be used as a cost-effective way of reducing subthreshold depressive symptoms. Health promotion campaigns on other major sources of disease burden, such as heart disease and cancer, routinely include information on actions that can be taken to reduce risk. Jorm and Griffiths [13] called for this approach to be extended to self-help interventions for depression, with the aim of reducing subthreshold depressive symptoms and the risk of progressing to a depressive disorder. If applied successfully, such an approach would have the potential to reduce the distribution of symptoms across the whole population. However, due to the risk of suicide and detriment to functioning if symptoms deteriorate or do not improve, such an approach would also need clear guidelines on when to seek professional help rather than relying on self-help strategies. If a health promotion approach were to be applied, the first step is to identify a small number of self-help actions that are likely to be effective and that can be applied easily by many people at low cost. A number of reviews have examined the evidence for self-help or complementary therapies for depression [14-19]. These have found reasonable evidence for St John's wort, S-adenosylmethionine, exercise, bibliotherapy, and light therapy. Although these reviews are informative, we decided to undertake our own systematic review of the evidence because prior reviews were either outdated (in a rapidly growing research area), only reviewed treatments for depressive disorders and not subthreshold symptoms, or they focused solely on complementary and alternative therapies rather than other self-help strategies. Methods Selection of treatments to review Treatments were identified from previous systematic reviews of complementary and self-help treatments for depression [14,19]. Not all of these treatments were included for review here as some required the assistance of another (...truncated)