Summary of findings 2. Music therapy plus standard care compared to active intervention plus standard care.

Patient or population: people with substance use disorders Setting: detox and inpatient/outpatient rehabilitation settings Intervention: music therapy plus standard care Comparison: active intervention plus standard care
Outcomes	Anticipated absolute effects* (95% CI)		Relative effect (95% CI)	No. of participants (studies)	Certainty of the evidence (GRADE)	Comments
	Risk with active intervention	Risk with music therapy
Psychological outcomes (depression) Assessed with: Beck Depression Inventory Scale: 0–63 (higher score worse) Follow‐up: end of treatment	Mean depression for active intervention was 20.3	Music therapy was 1.49 lower (4.98 lower to 2.00 higher)	—	110 (1 RCT)a	⊕⊕⊕⊝ Moderateb	—
Substance craving Assessed with: various scales Scale: various (higher score worse) Follow‐up: end of treatment	—	Mean substance craving in music therapy was 0.04 standard deviations lower (0.56 lower to 0.48 higher)	—	232 (3 RCTs)a	⊕⊕⊝⊝ Lowb,c	—
Motivation for treatment/change Assessed with: various scales Scale: various (higher score better) Follow‐up: end of treatment	—	Mean motivation for treatment in music therapy was 0.46 standard deviations higher (0 lower to 0.93 higher)	—	411 (5 RCTs)a	⊕⊕⊕⊝ Moderateb	—
Motivation to stay sober/clean Assessed with: Likert Scale: 1–7 (higher score better) Follow‐up: end of treatment	Mean motivation to stay sober in active intervention ranged from 6.2 to 6.4	Music therapy was 0.34 higher (0.11 lower to 0.78 higher)	—	258 (3 RCTs)a	⊕⊕⊕⊝ Moderateb	—
Retention in treatment	—	—	—	—	—	No studies reported retention in treatment.
Serious adverse events	—	—	—	—	—	No studies reported serious adverse events.
GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.

^aNumber of participants adjusted for cluster randomisation.
^bDowngraded one level for imprecision: optimal information size not met.
^cDowngraded one level for inconsistency: substantial heterogeneity (I² = 70%) likely affecting interpretation of results and with no plausible explanation.