Study designs of evaluations included in the review
Studies of any design were eligible for inclusion.
Specific interventions included in the review
Studies of psychological interventions that included a central verbal face-to-face component were eligible for inclusion. Studies of exercise therapy, drama therapy, bibliotherapy, and others that did not include a central face-to-face component were excluded. All but one of the included studies evaluated cognitive therapy; one evaluated psycho-educational treatment. The length of treatment varied from 15 to 39 sessions.
Participants included in the review
Studies of adults aged 18 years and older, who had failed to respond to at least one antidepressant medication, were eligible for inclusion. The trialists' definition of nonresponse was considered adequate. The participants had to have a definite or probable diagnosis of major depressive disorder before treatment, according to research diagnostic criteria: a score of greater than 14 on the Hamilton Rating Score for Depression (HRSD), or greater than 19 on the Beck Depression Inventory. Studies that did not explicitly report that participants had failed to respond to medication prior to the intervention were excluded.
Outcomes assessed in the review
The main outcome of interest was depression, as measured by the HRSD.
How were decisions on the relevance of primary studies made?
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.