Young 2010a.

Methods	Design: RCT Conducted by the team who developed the intervention: unclear
Participants	Description: targeted Cut‐point for inclusion for indicated studies: CES‐D ≥ 16.0 What risk was basis of inclusion for selected studies:  N/A Diagnostic interview to exclude those with current or previous depression: those who met diagnostic criteria for depression were excluded. Unclear whether those with past episodes of depression were also excluded. Baseline severity of depression: CES‐D: 15.2 (subthreshold)   Mean age: 14.5 Age range: 11 to 17 Percentage male: 40.3% Setting: school   State what psychiatric diagnoses were excluded: panic disorder, obsessive‐compulsive disorder, post‐traumatic stress disorder, conduct disorder, oppositional defiance disorder, bipolar disorder, psychosis and ADHD (untreated) Suicide risk excluded: yes Parents with history of schizophrenia/bipolar disorder excluded: no   Country: USA
Interventions	Broad category: IPT (for further information on intervention components, see Table 3) Manualised: unclear Online: no Name of programme: Interpersonal Psychotherapy‐Adolescent Skills Training Number of sessions: 8 sessions Length of sessions: 90 minutes Intensity (total number of hours): 12 hours Duration of treatment period: unclear Group size: 4 to 6 Delivered by: mental health experts Fidelity: assessed but unclear if assessed as adequate Type of comparison: TAU comprising referral to school counsellors and/or social worker as required
Outcomes	Diagnosis: K‐SADS Name of self‐report depression measure: CES‐D Name of clinical report depression measure: N/A Name of anxiety measure: N/A Name of general functioning measure: CGAS Assessment points: post‐intervention, 12 months (medium‐term) and 18 months (long‐term)
Notes	Author contacted for methodological detail: no Author contacted for treatment manual: no Author contacted for outcome data: yes (provided)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"...table of random numbers..." (p.428)
Allocation concealment (selection bias)	Unclear risk	No information specified
Blinding (performance bias and detection bias) Subjects	High risk	The nature of the trial suggests it is unlikely participants could have been blind to the fact they were allocated to treatment as usual. However, without access to the participant information sheets and PLS, level of blinding cannot be ascertained.
Blinding (performance bias and detection bias) Assessors	Unclear risk	"The evaluations were conducted by independent evaluators..." (p.429) Primary outcomes, however, were self‐reported. Assessor blinding therefore not applicable.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Proportion of participants with incomplete post‐intervention self‐reported depression scores: 2.8% Means and SDs used in meta‐analysis based on what data: observed cases Intention‐to‐treat analyses: using hierarchical linear modelling and LOCF
Selective reporting (reporting bias)	Unclear risk	Protocol not available
Other bias	Unclear risk	No information specified
Implementation integrity	Unclear risk	Implementation integrity assessed: yes Implementation integrity adequate: N/A Implementation integrity reported: N/A