The authors concluded that support groups did benefit caregivers of relatives with mental illness, but there was little evidence of long-term benefit. There was an extensive search and the selected studies had various methods, but the lack of transparency in the review process and the uncertain quality of these studies limit the reliability of the conclusions.

To evaluate the effectiveness of mutual support groups for family caregivers of individuals with severe mental health problems.

MEDLINE, EMBASE, CINAHL, PsycINFO, the Cochrane Library, NRR, and SIGLE were searched for English-language articles from 1989 to 2008. The search terms were reported. A range of psychiatry and psychology journals were handsearched, and the reference lists of the identified articles were scanned for additional studies. Unpublished material was sought from leading researchers on this topic.

All studies evaluating family-led mutual support programmes for caregivers of relatives with a severe mental illness were eligible for inclusion. Qualitative studies were sought to explore the perceived benefits and limitations of the support groups.

In the included experimental or quasi-experimental studies, most of the family caregivers were Chinese, female, middle aged (40 to 58 years), parents or spouses of the patient, and elementary or high school-educated. Half of the included studies were mainly of families of middle social class. Most patients were male, with an average age of 31 years and more than nine years of illness, diagnosed as schizophrenia, schizoaffective disorder, bipolar affective disorder, or dementia. The intervention content, frequency, and duration varied substantially, and the inclusion of both caregivers and patients was inconsistent across studies. Comparison groups included routine community or psychiatric care, psycho-education, or multiple-family group intervention. Outcomes included family burden, social support, levels of stress and coping ability, use of community services, knowledge of mental illness, relapse, psychiatric symptoms, and functioning. The most frequently reported data collection methods were questionnaire and/or qualitative interview. Most of the studies were conducted in Asia and one was conducted in the UK.

The authors did not state how many reviewers selected the studies.

Elements of the quality of complex interventions were examined, including the extent of the intervention development, structure, and content. Attrition, the reasons for withdrawal, and power calculations were assessed. The bias in the experimental and quasi-experimental studies was not assessed.

The authors did not state how many reviewers assessed the quality.

The data were extracted on the direction of the effect for the outcomes of interest.

The authors did not state how many reviewers extracted the data.

A narrative synthesis was provided, with the results grouped by study design. The differences between studies were available for interpretation in tables.

Twelve studies were included in the review. There were five experimental or randomised controlled studies (n=376 families or caregivers), three quasi-experimental studies with non-equivalent comparison groups (n=251 families or caregivers), and four qualitative studies (n=119 caregivers or patients). The qualitative studies are not critically appraised in this abstract. Most of the quantitative studies gave only brief descriptions of the development, structure, and content of the intervention; the attrition rates were reported in four studies and ranged from 10 to 100% and a power calculation was carried out in three studies. Where reported, the follow-up ranged from one month to 18 months after the intervention.

In the experimental studies, greater improvements in favour of the support groups were reported in terms of personal distress and management of family life, anxiety reduction, and increased use of community resources. Three controlled trials reported significant improvements in family and consumer psychosocial function and/or mental state, but attrition was a problem. Increases in knowledge about the illness, family and peer support, and positive attitudes towards ill relatives, and reductions in depression and family burden were reported as positive family outcomes in two quasi-experimental studies.

Mutual support programmes did provide benefits for caregivers of relatives with mental illness. There was little empirical evidence to support the long-term benefits for families' psychosocial well-being and the patients' health conditions.

The review question was clear and it was supported by broad, but potentially reproducible inclusion criteria for the study design, intervention, and population. The search strategy was extensive in its coverage of published and unpublished data, but the restriction to English-language articles means that studies might have been missed and language bias was possible. The review process was poorly reported, which could substantially reduce the reliability of the review. Some relevant aspects of study quality were assessed, but the extent of methodological bias was unclear. Study details were provided, and the method of synthesis was appropriate given the apparent heterogeneity between studies.

This review had an extensive search and included a variety of study designs to explore a complex question, but the lack of transparency in the review process, and uncertain quality of the studies, means that the extent to which the authors' conclusions are reliable is unclear.

Practice: The authors stated that early and accessible support group interventions were likely to be needed by caregivers after patients were discharged from hospital.

Research: The authors stated that further studies evaluating the short- and long-term effects of support groups were needed. The potential therapeutic mechanisms should form part of future intervention development and evaluation. Specific research for improving treatment integrity, testing feasibility in practice, and using process evaluation was recommended.

Not stated.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.