Table 1.

WMH sample characteristics by World Bank income categories^a

	Survey	Sample characteristicsb	Field dates	Age range, yearsc	Sample size		Response rated
					Part 1	Part 2
I. Low-/lower-middle-income countries
Colombia	NSMH	All urban areas (73% of the total national population)	2003	18–65	4426	2381	87.7
Nigeria	NSMHW	21 of 36 states (57% of the national population)	2002–3	18–100	6752	2143	79.3
People’s Republic of China – Beijing/Shanghai	B-WMH/S-WMH	Beijing and Shanghai metropolitan areas	2002–3	18–70	5201	1628	74.7
Peru	EMSMP	Nationally representative	2004–5	18–65	3930	1801	90.2
Ukraine	CMDPSD	Nationally representative	2002	18–91	4724	1719	78.3
II. Upper-middle-income countries
Brazil – São Paulo	São Paulo	São Paulo metropolitan area	2005–7	18–93	5037	2942	81.3
Bulgaria	NSHS	Nationally representative	2003–7	18–98	5318	2233	72
Lebanon	L.E.B.A.N.O.N.	Nationally representative	2002–3	18–94	2857	1031	70
Colombia – Medellin	MMHHS	Medellin metropolitan area	2011–12	19–65	3261	1673	97.2
Mexico	M-NCS	All urban areas (75% of the total national population)	2001–2	18–65	5782	2362	76.6
Romania	RMHS	Nationally representative	2005–6	18–96	2357	2357	70.9
South Africa	SASH	Nationally representative	2003–4	18–92	4315	4315	87.1
III. High-income countries
Australia	NSMHWB	Nationally representative	2007	18–85	8463	8463	60
Belgium	ESEMeD	Nationally representative (national register of Belgium residents)	2001–2	18–95	2419	1043	50.6
France	ESEMeD	Nationally representative (of households with listed telephone numbers)	2001–2	18–97	2894	1436	45.9
Germany	ESEMeD	Nationally representative	2002–3	18–95	3555	1323	57.8
Israel	NHS	Nationally representative	2002–4	21–98	4859	4859	72.6
Italy	ESEMeD	Nationally representative (municipality resident registries)	2001–2	18–100	4712	1779	71.3
Japan	WMHJ 2002–2006	11 metropolitan areas	2002–6	20–98	4129	1682	55.1
Spain – Murcia	PEGASUS-Murcia	Murcia region	2010–12	18–64	2621	1459	67.4
Netherlands	ESEMeD	Nationally representative (municipal postal registries)	2002–3	18–95	2372	1094	56.4
New Zealand	NZMHS	Nationally representative	2003–4	18–98	12 790	7312	73.3
Northern Ireland	NISHS	Nationally representative	2004–7	18–97	4340	1986	68.4
Portugal	NMHS	Nationally representative	2008–9	18–81	3849	2060	57.3
Spain	ESEMeD	Nationally representative	2001–2	18–98	5473	2121	78.6
USA	NCS-R	Nationally representative	2002–3	18–99	9282	5692	70.9
IV. Total					125 718	68 894	70.4

WMH, World Mental Health; NSMH, Colombian National Study of Mental Health; NSMHW, Nigerian Survey of Mental Health and Wellbeing; B-WMH, Beijing World Mental Health Survey; S-WMH, Shanghai World Mental Health Survey; EMSMP, La Encuesta Mundial de Salud Mental en el Peru; CMDPSD, Comorbid Mental Disorders during Periods of Social Disruption; NSHS, Bulgaria National Survey of Health and Stress; L.E.B.A.N.O.N., Lebanese Evaluation of the Burden of Ailments and Needs of the Nation; MMHHS, Medellín Mental Health Household Study; M-NCS, Mexico National Comorbidity Survey; RMHS, Romania Mental Health Survey; SASH, South Africa Health Survey; NSMHWB, National Survey of Mental Health and Wellbeing; ESEMeD, European Study of the Epidemiology of Mental Disorders; NHS, Israel National Health Survey; WMHJ 2002–2006, World Mental Health Japan Survey; PEGASUS-Murcia, Psychiatric Enquiry to General Population in Southeast Spain-Murcia; NZMHS, New Zealand Mental Health Survey; NISHS, Northern Ireland Study of Health and Stress; NMHS, Portugal National Mental Health Survey; NCS-R, US National Comorbidity Survey Replication.

^aWorld Bank data from May 2012. Some of the WMH countries have moved into new income categories since the surveys were conducted. The income groupings above reflect the status of each country at the time of data collection. For the current income category of each country, see The World Bank (2015).

^bMost WMH Surveys are based on stratified multistage clustered area probability household samples in which samples of areas equivalent to counties or municipalities in the USA were selected in the first stage followed by one or more subsequent stages of geographic sampling (e.g. towns within counties, blocks within towns, households within blocks) to arrive at a sample of households, in each of which a listing of household members was created and one or two people were selected from this listing to be interviewed. No substitution was allowed when the originally sampled household resident could not be interviewed. These household samples were selected from census area data in all countries other than France (where telephone directories were used to select households) and the Netherlands (where postal registries were used to select households). Several WMH surveys (Belgium, Germany, Italy) used municipal resident registries to select respondents without listing households. The Japanese sample is the only totally unclustered sample, with households randomly selected in each of the 11 metropolitan areas and one random respondent selected in each sample household. Of the 26 surveys, 18 are based on nationally representative household samples.

^cFor the purposes of cross-national comparisons we limit the sample to those aged 18+ years.

^dThe response rate is calculated as the ratio of the number of households in which an interview was completed to the number of households originally sampled, excluding from the denominator households known not to be eligible either because of being vacant at the time of initial contact or because the residents were unable to speak the designated languages of the survey. The weighted average response rate is 70.4%.