Garcia 2011.

Methods	Design: RCT Conducted by the team who developed the intervention: yes
Participants	Description: universal Cut‐point for inclusion for indicated studies: N/A What risk was basis of inclusion for selected studies: N/A Diagnostic interview to exclude those with current or previous depression: not undertaken. Reported that 5.1% of participants had experienced a previous mental health condition. Baseline severity of depression: DASS‐d: 10.9 (mild)   Mean age: 14.8 Age range: 14 to 16 Percentage male: 0.0% Setting: school   State what psychiatric diagnoses were excluded: none Suicide risk excluded: no Parents with history of schizophrenia/bipolar disorder excluded: no   Country: Mexico
Interventions	Broad category: third wave (for further information on intervention components, see Table 3) Manualised: yes Online: no Name of programme: Project Wings Number of sessions: 16 sessions Length of sessions: 3 hours Intensity (total number of hours): 48 hours Duration of treatment period: 16 weeks plus booster sessions at 3 and 7 months Group size: unclear Delivered by: mental health workers (youth workers) Fidelity: not assessed Type of comparison: AP
Outcomes	Diagnosis: N/A Name of self‐report depression measure: DASS‐d Name of clinical report depression measure: N/A Name of anxiety measure: DASS‐a Name of general functioning measure: N/A Assessment points: post‐intervention, 3 months (short‐term), 9 months (medium‐term)
Notes	Author contacted for methodological detail: yes (not provided) Author contacted for treatment manual: yes (not provided) Author contacted for outcome data: no
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"A computerised permuted block randomisation schedule was created..." (p.439)
Allocation concealment (selection bias)	Unclear risk	No information specified
Blinding (performance bias and detection bias) Subjects	Low risk	The nature of the trial suggests it is likely participants could have remained blind to the fact they were allocated to a placebo control group. 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	All outcomes self‐reported and there is no report of blinding. Assessor blinding therefore not applicable.
Incomplete outcome data (attrition bias) All outcomes	High risk	Proportion of participants with incomplete post‐intervention self‐reported depression scores: 14.30% Means and SDs used in meta‐analysis based on what data: observed cases (those with at least 2 post‐intervention assessments) Intention‐to‐treat analyses: not undertaken
Selective reporting (reporting bias)	Unclear risk	Protocol not available
Other bias	High risk	Trial conducted by those who developed the intervention
Implementation integrity	Unclear risk	Implementation integrity assessed: unclear if assessed Implementation integrity adequate: N/A Implementation integrity reported: N/A