Studies of prevention or treatment must meet these additional criteria:

• Random allocation of participants to comparison groups

• Follow up (end point assessment) of at least 80% of those entering the investigation

• Outcome measure of known or probable clinical importance

• Analysis consistent with study design.

Studies of diagnosis must meet these additional criteria:

• Inclusion of a spectrum of participants, some, but not all of whom have the disorder or derangement of interest

• Diagnostic (gold) standard (eg, diagnosis according to DSM-IV or ICD-10 criteria after assessment by clinically qualified interviewer) preferably with documentation of reproducible criteria for subjectively interpreted diagnostic standard (eg, report of statistically significant measure of agreement among observers)

• Each participant must receive both the new test and some form of the diagnostic standard

• Interpretation of diagnostic standard without knowledge of test result

• Interpretation of test without knowledge of diagnostic standard result

• Analysis consistent with study design.

Studies of prognosis must meet these additional criteria:

• Inception cohort (first onset or assembled at a uniform point in the development of the disease) of individuals, all initially free of the outcome of interest

• Follow up of at least 80% of patients until the occurrence of a major study end point or to the end of the study

• Analysis consistent with study design.

Studies of causation must meet these additional criteria:

• Observations concerning the relationship between modifiable exposures and putative clinical outcomes

• Prospective data collection with clearly identified comparison group(s) for those at risk of the outcome of interest (in descending order of preference, from randomised controlled trials, quasi-randomised controlled trials, non-randomised controlled trials, cohort studies with case by case matching or statistical adjustment to create comparable groups, or nested case control studies)

• Masking of observers of outcome to exposure (this criterion is assumed to be met if the outcome is objective)

• Analysis consistent with study design.

Studies of quality improvement and continuing education must meet these additional criteria:

• Random allocation of participants or units to comparison groups

• Follow up of at least 80% of participants

• Outcome measure of known or probable clinical importance

• Analysis consistent with study design.

Studies of the economics of healthcare programmes or interventions must meet these additional criteria:

• The economic question addressed must be based on comparison of alternative diagnostic or therapeutic services or quality improvement strategies

• Activities must be compared on the basis of the outcomes produced (effectiveness) and resources consumed (costs)

• Evidence of effectiveness must be from a study (or studies) of real (not hypothetical) patients, which meets the journal criteria for diagnosis, treatment, quality improvement, or a review article

• Results should be presented in terms of the incremental or additional costs and outcomes of one intervention over another

• Where there is uncertainty in the estimates or imprecision in the measurement, a sensitivity analysis should be done.

Studies of differential diagnosis must meet these additional criteria:

• Cohort of patients who present with a similar, initially undiagnosed but reproducibly defined clinical problem

• Clinical setting, including referral filter, is explicitly described

• At least 80% of initially undiagnosed patients are followed up for ≥1 month for acute disorders or ≥1 year for chronic or relapsing disorders.

Review articles must meet these additional criteria:

• Statement of the clinical topic

• An identifiable description of the methods indicating the sources

• Explicit statement of the inclusion and exclusion criteria applied for selecting articles for detailed review

• At least one article included in the review must meet the above noted criteria for treatment, diagnosis, prognosis, causation, quality improvement, or the economics of healthcare programmes.

Qualitative studies must meet these additional criteria:

• Content must relate to how people feel or experience certain situations, specifically those situations that relate to health care

• Data collection methods must be appropriate for qualitative studies (eg, unstructured interviews, semi-structured interviews, participant observation of people in natural settings, focus groups, review of documents or text)

• Data analyses must be appropriate for qualitative studies (ie, the primary analytical mode is inductive rather than deductive; units of analysis are ideas, thoughts, concepts, phrases, incidents, or stories which are ultimately classified into categories or themes).

These criteria are subject to modification if, for example, it is found feasible to apply higher standards that increase the validity and applicability of studies for clinical practice. The objective of Evidence-Based Mental Health is to abstract only the best literature, consistent with a reasonable number of articles making it through the filter.

Evidence-Based Mental Health has 3 related journals: Evidence-Based Medicine, ACP Journal Club, and Evidence-Based Nursing. Abstracts in their entirety, or a modification thereof, may appear in this journal and a footnote indicating this will appear with each piece. This arrangement increases the number of journals that are regularly searched.

Articles meeting the criteria set out above are abstracted according to the procedure for more informative abstracts,¹ with the following modification: abstracts can be up to 440 words in length; and each is reviewed by an expert in the content area covered by the article and a commentary is added to provide the context of the article in the research that has preceded it; to provide any important methodological problems that affect interpretation; and to provide recommendations for clinical application. The author of the article is given an opportunity to review the abstract and commentary before publication. If there is not enough space to accommodate abstracts for all articles that meet review criteria, citations for the extra articles will be noted in the section of the journal titled Other Articles Noted.