Table.

Prevalence, incidence, and sex differences (when reported) for major depressive disorder from large population cohort studies of adolescents by age (years)

	Diagnostic interview	Sample size	Prevalence % (SE* or 95% CI†)		Incidence
			Current	Lifetime
National comorbidity survey26
15–24 years (Data for 15–16 shown)	CIDI	1769	7‡ (1·8*)	14·6 (2·6)	··
Female	CIDI	··	12·4	23·4	··
Male	CIDI	··	1·5	5·7	··
Great Smoky Mountains study27
11 years	CAPA	901	1·9§ (1·0–3·5†)	··	··
13 years	CAPA	833	2·6§ (1·3–5·3†)	··	··
15 years	CAPA	1136	3·7§ (2·3–6·0†)	··	··
16 years	CAPA	1101	3·1§ (1·8–5·3†)	··	··
Oregon adolescent depression project6
14–18 years	K-SADS	1709	2·9¶	20·4	7·8
Female	K-SADS	··	3·4	24·8	10·4
Male	K-SADS	··	2·0	11·6	4·8
British child and adolescent mental health survey28
11–12 years	DAWBA	1901	0·4‡ (0·14*)	··	··
13–15 years	DAWBA	2624	1·9‡ (0·28*)	··	··
Dunedin longitudinal study25
11 years	DISC-C	653	1·1||	1·1	1·07
Female	DISC-C	··	0·3	··	0·3
Male	DISC-C	··	1·8	··	1·8
13 years	DISC-C		2·1||	3·2	2·1
Female	DISC-C	··	2·2	··	2·2
Male	DISC-C	··	2·1	··	2·1
15 years	DISC-C		2·8||	5·7	2·5
Female	DISC-C	··	4·4	··	4·4
Male	DISC-C	··	1·2	··	0·6
18 years	DIS		16·8||	20·7	15·0
Female	DIS	··	23·2	··	20·7
Male	DIS	··	10·8	··	9·6

CIDI=composite international diagnostic interview. CAPA=child and adolescent psychiatric assessment. K-SADS=schedule for affective disorders and schizophrenia for school-age children. DAWBA=development and well-being assessment. DISC-C=diagnostic interview schedule for children-child version. DIS=diagnostic interview schedule.

^‡Current=28–30 days.

^§Current=3 months (any depressive disorder).

^¶Current=point.

^||Current=1 year.

Timeframes refer to period over which symptoms of depression were assessed.