Postnatal depression (PND) affects up to one in four mothers. However, they may experience barriers to access to conventional treatments, indicating a need for alternatives such as arts-based interventions. A previous trial showed that a 10-week singing intervention could alleviate symptoms of PND.

To evaluate, in a larger sample and across a longer timeframe than previously, the clinical effectiveness, implementation effectiveness and cost-effectiveness of the Melodies for Mums (M4M) singing intervention for symptoms of PND.

One-hundred and ninety-nine mothers experiencing symptoms of PND (Edinburgh Postnatal Depression Scale score ≥10) and their babies were randomised to 10 weeks of in-person singing sessions (M4M, n = 133) or an active control (existing community-based mother–baby activities, n = 66). Mothers were re-assessed at weeks 6, 10, 20 and 36 for depression, healthcare use for themselves and their babies, and health-related quality of life according to the EQ5D-3. The perceived acceptability (Acceptability of Intervention Measure), appropriateness (Intervention Appropriateness Measure) and feasibility (Feasibility of Intervention Measure) of the activity were also assessed at week 6. Trial registration number: NCT04834622.

Mothers in both groups experienced attenuation of depressive symptoms by week 10; however, those in the singing group maintained lower EPDS scores than those in the control group at week 20 (10.7 v. 12.2 (mean difference 95% CI [−2.96, −0.22]), P = 0.023) and week 36 (9.85 v. 11.4 [−2.93, −0.19], P = 0.026). Mothers in the singing group were also more likely to remain in the study (77 v. 57%, χ2(1) = 12.92, P < 0.001) and found their programme more acceptable (4.75 v. 4.0 [0.25, 0.83], U = 2436.5, P < 0.001), appropriate (4.25 v. 3.88 [0.12, 0.62], U = 2241.5, P < 0.001) and feasible (4.75 v. 4.0 [0.41, 0.91], U = 2568.0, P < 0.001). Finally, M4M was associated with 15 extra days of health and was found to be cost-effective (£126–539 per dyad).

M4M had a long-lasting effect on symptoms of PND and was perceived to be more suitable than existing activities; thus, M4M represents a worthwhile investment for healthcare systems as an intervention for mothers experiencing symptoms of PND.