Klein 2004.

Methods	Design: RCT Phases: acute (12 weeks), continuation (16 weeks), maintenance (52 weeks) Comparison groups: CBASP vs assessment only Funded by: Bristol‐Myers Squibb
Participants	Number of participants randomized (NRCT: number of participants included): 82 Criteria for relapse/recurrence: "Recurrence was defined in the protocol as a HRSD‐24 [HAM‐D] score of 16 or greater on two consecutive visits and a diagnosis of MDD as determined from a DSM–IV MDD checklist administered by the independent evaluator. At the second of these visits, the recurrence also needed confirmation by the site's senior investigator on the basis of a clinical interview." (p. 683) Age distribution in sample (mean): CBASP: 44.2 (SD 11.7) years; assessment only: 46.0 (SD 11.1) years Sex distribution in sample (% women): CBASP: 81.0; assessment only: 52.5 Diagnoses in sample: CBASP: 50.0% chronic major depressive disorder, 26.2% double depression, 23.8% recurrent depressive disorder with incomplete remission between episodes; assessment only: 60.0% chronic major depressive disorder, 20.0% double depression, 20.0% recurrent depressive disorder with incomplete remission between episodes Depression severity at continuation/maintenance baseline (mean): HAM‐D‐24: CBASP: 6.6 (SD 3.8); assessment only: 6.2 (SD 4.4) Age of onset (mean): CBASP: 27.0 (SD 12.4) years; assessment only: 29.5 (SD 13.5) years Length current/last major episode in months (mean): CBASP: 92.4 (SD 115.2); assessment only: 85.2 (SD 122.4)
Interventions	Maintenance treatment (52 weeks) Name (class and type): CBASP Planned number of sessions: 13 Number of sessions (mean): 11.1 (SD 3.8) Name (class and type): assessment only Planned number of sessions: 13 Number of sessions: unclear Notes: "In both conditions, all psychotropic medication and non‐protocol psychotherapy were prohibited." (p. 683)
Outcomes	Relapse/recurrence HRSD‐24 (HAM‐D) mean Dropout any
Notes	Probably conflict of interest because of funding.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information
Allocation concealment (selection bias)	Unclear risk	No information
Blinding of participants and personnel (performance bias) All outcomes	High risk	As CBASP was compared to assessment only, blinding of participants was not possible.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "The primary outcome measure throughout all phases of the study was the HRSD‐24, which was administered by certified rates who were unaware of patient's treatment condition. Patients in the CBASP condition were also seen by the independent evaluator every 4 weeks but did not receive an honorarium. All patients were reminded at each visit not to mention anything that might reveal their treatment condition to the independent evaluator. If patients had questions or concerns about the study, they were instructed to raise them with the project coordinator rather than the independent evaluator. In the rare instances that the blind was broken, the patient was seen by a different independent evaluator at subsequent visits. In both conditions, all psychotropic medication and non‐protocol psychotherapy were prohibited." (p. 683)
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "We compared time to recurrence between the CBASP and assessment only groups using survival analysis. Patients who failed to complete the maintenance phase were included in these analyses using all available data up to the time of exiting the study." (p. 684)
Selective reporting (reporting bias)	Unclear risk	Study protocol only described outcome measurements for the acute phase.
Other bias	Low risk	Insufficient treatment adherence. Quote: "Sessions were videotaped and reviewed weekly–biweekly by the site supervisor or James P. McCullough to assess adherence to the treatment procedures. Adherence was assessed using a rating scale described in McCullough (2000). When non‐adherence was identified, it was immediately discussed with the therapist and efforts at remediation were provided." (p. 683) Allegiance bias/conflict of interest: some authors were well‐known CBASP therapists (e.g. J McCullough), but there were also other authors; interests were balanced across authors. Attention bias: in both conditions, participants saw the therapist or project co‐ordinator every 4 weeks. The project co‐ordinator provided them with some attention but no active treatment.