Table 2

Interventions, effect size estimates and costs by condition

Intervention		Base value	Min. value	Max. value	Average monthly cost per adolescent (2019 US$)
Intervention		Base value	Min. value	Max. value	LIC	LMIC	UMIC	HIC
Prevention interventions
Universal prevention of anxiety and depression	School-based prevention delivered by teachers⁽ 21 ⁾				$0.01	$0.08	$0.37	$7.31
	Relative risk of developing internalising disorder (both anxiety and depression), postintervention⁽ 80 ⁾	0.39	0.26	0.59
	Relative risk of developing internalising disorder (both anxiety and depression), 1–3 months⁽ 80 ⁾	0.35	0.24	0.53
	Relative risk of developing internalising disorder (both anxiety and depression), 6–9 months⁽ 80 ⁾	0.49	0.37	0.64
	Relative risk of developing depression, postintervention⁽ 80 ⁾	0.41	0.24	0.69
	Relative risk of developing depression, 1–3 months⁽ 80 ⁾	0.35	0.24	0.53
	Relative risk of developing depression, 6–9 months⁽ 80 ⁾	0.46	0.35	0.62
	Relative risk of developing anxiety, postintervention⁽ 80 ⁾	0.25	0.10	0.65
Indicated prevention of depression	Screening and in person group-based CBT delivered in schools⁽ 21 ⁾				<$0.01	$0.01	$0.04	$0.79
	Relative risk of developing depression, postintervention⁽ 21 ⁾	0.32	0.14	0.73
	Relative risk of developing depression, 6 months⁽ 21 ⁾	0.34	0.20	0.59
	Relative risk of developing depression, 1 year⁽ 21 ⁾	0.71	0.35	1.43
	Relative risk of developing depression, 2 years⁽ 21 ⁾	0.74	0.41	1.36
Prevention of suicide	Universal school-based prevention⁽ 81 ⁾				<$0.01	$0.01	$0.01	$0.69
	OR for incident suicide attempts at 3 months⁽ 81 ⁾	0.78	0.42	1.44
	OR for incident suicide attempts at 12 months⁽ 81 ⁾	0.45	0.24	0.85
	Targeted prevention in hospitals among adolescents who have self-harmed⁽ 26 ⁾				$0.05	$0.08	$0.14	$6.52
	Risk ratio of probability of suicide among people who have self-harmed after receiving targeted follow-up⁽ 26 ⁾	0.11	0.02	0.45
Treatment interventions
Treatment of anxiety	In-person group CBT⁽ 23 ⁾				$0.04	$0.12	$0.27	$15.60
	OR for remission of anxiety, postintervention⁽ 23 ⁾	7.86	3.83	16.12
	Summary OR for remission of anxiety, 2 years⁽ 23 ⁾	3.22	0.96	10.75
	Individual CBT delivered via internet platform				$2.19	$2.39	$3.91	$157.64
	OR for remission of anxiety, postintervention⁽ 23 ⁾	7.86	3.83	16.12
	Summary OR for remission of anxiety, 2 years⁽ 23 ⁾	3.22	0.96	10.75
	Internet-based guided self-help⁽ 24 ⁾				$0.53	$0.90	$1.58	$70.97
	OR for remission of anxiety, post-treatment⁽ 24 ⁾	5.41	2.26	12.90
Treatment of mild and moderate depression	In-person group CBT⁽ 82 ⁾				$0.04	$0.12	$0.27	$15.60
	Relative risk of depression, post-treatment⁽ 82 ⁾	0.23	0.13	0.40
	Relative risk of depression, 4–9 months⁽ 82 ⁾	0.37	0.15	0.92
	Individual CBT delivered via internet platform				$2.19	$2.39	$3.91	$157.64
	Relative risk of depression, post-treatment⁽ 82 ⁾	0.23	0.13	0.40
	Relative risk of depression, 4–9 months⁽ 82 ⁾	0.37	0.15	0.92
	Internet-based guided self-help				$0.53	$0.90	$1.58	$70.97
	Relative risk of depression, post-treatment⁽ 82 ⁾	0.23	0.13	0.40
	Relative risk of depression, 4–9 months⁽ 82 ⁾	0.37	0.15	0.92
Treatment of severe depression	In-person individual CBT and medication⁽ 83 ⁾				$1.61	$3.95	$8.03	$444.54
	OR for remission of severe depression, post-treatment⁽ 84 ⁾	3.00	1.58	5.79
Treatment of bipolar disorder	Family-focused treatment and medication⁽ 37 ⁾				$4.14	$5.12	$7.91	$182.88
	HR for recovery from depressive symptoms, 2 years⁽ 37 ⁾	1.85	1.04	3.29

Costs represent monthly costs per adolescent given in 2019 US$ for every year after the first. Costs are slightly higher in the first year to reflect start-up costs, primarily initial trainings. For more information on the differences between relative risks, ORs and HRs, please see online supplemental file 1.
CBT, cognitive behavioural therapy; HIC, high-income country; HR, hazard ratio; LIC, low-income country; LMIC, lower-middle income country; OR, odds ratio; UMIC, upper-middle income country.