Mental health outcomes
Study	Depression	Anxiety	Quality of life	Stress	Negative affect	Other
Davis 2014a	Not assessed	Not assessed	Not assessed	Not assessed	Depression, Anxiety and Stress Scales (DASS): assessed at 1 month post‐baseline, data only reported for intervention arm	Not assessed
Davis 2014b	Not assessed	Not assessed	Not assessed	Perceived Stress Scale (PSS): assessed at 6 months post‐quit. Significantly greater reduction in intervention than control arm (P = 0.03) Intervention arm scored 16.2 at baseline and 13.0 at 6 months post‐quit (−3.2); comparator arm scored 17.5 at baseline and 16.9 at 6 months post‐quit (−0.6). This difference was not significant when analysed as intention to treat	Not assessed	Not assessed
de Souza 2020	Hospital Anxiety and Depression Scale (HAD): assessed at 4 and 12 weeks. No difference across conditions in the change between 4 weeks and 12 weeks (F (3.421) = 17.549; P = 0.074). Intervention arm scored 6.4 at 4 weeks and 6.9 at 12 weeks (+0.5); comparator arm scored 7.6 at 4 weeks and 6.0 at 12 weeks (−1.6)	HAD: assessed at 4 and 12 weeks. No difference across conditions in the change between 4 weeks and 12 weeks (F (0.352) = 1.668; P = 0.558). Intervention arm scored 10.4 at 4 weeks and 8.9 at 12 weeks (−1.4); comparator arm scored 9.5 at 4 weeks and 8.7 at 12 weeks (−0.8)	Not assessed	Not assessed	Positive and Negative Affect Scale (PANAS): assessed at 4 and 12 weeks. No difference across conditions in the change between 4 weeks and 12 weeks (F (0.015) = 0.278; P = 0.903). Intervention arm scored 20.3 at 4 weeks and 19.1 at 12 weeks (−1.2); comparator arm scored 19.2 at 4 weeks and 17.7 at 12 weeks (−1.4)	Positive affect ‐ PANAS: assessed at 4 and 12 weeks. No difference across conditions in the change between 4 weeks and 12 weeks (F (0.904) = 14.395; P = 0.350). Intervention arm scored 25.9 at 4 weeks and 27.2 at 12 weeks (+1.2); comparator arm scored 25.3 at 4 weeks and 24.6 at 12 weeks (−0.7)
Vidrine 2016	Center for Epidemiologic Studies ‐ Depression Scale (CES‐D): assessed 6 times between quit date and 6 months post‐quit. No significant difference in the change between quit date and 6 months post‐quit between intervention arm and either control arm (CBT: β 0.03, 95% CI −0.16 to 0.22, P = 0.762; usual care: β −0.18, 95% CI −0.40 to 0.03, P = 0.099)	Not assessed	Not assessed	4‐item Perceived Stress Scale ‐ Short Form (PSS‐SF): assessed 6 times between quit date and 6 months post‐quit. No significant difference in the change between quit date and 6 months post‐quit between intervention arm and either control arm (CBT: β 0.09, 95% CI −0.10 to 0.28, P = 0.362; usual care: β −0.16, 95% CI −0.38 to 0.05, P = 0.141)	PANAS: assessed 6 times between quit date and 6 months post‐quit. No significant difference in the change between quit date and 6 months post‐quit between intervention arm and either control arm (CBT: β 0.08, 95% CI ‐0.11 to 0.27, p = 0.403; usual care: β ‐0.19, 95% CI ‐0.40 to 0.03, p = 0.086)	Positive affect ‐ PANAS: assessed 6 times between quit date and 6 months post‐quit. No significant difference in the change between quit date and 6 months post‐quit between intervention arm and either control arm (CBT: β ‐0.09, 95% CI ‐0.29 to 0.10, p = 0.337; usual care: β 0.09, 95% CI ‐0.13 to 0.30, p = 0.444)