Table 1.

WMH sample characteristics by World Bank income categories.^a

					Sample size
Country by income category	Surveyb	Sample characteristicsc	Field dates	Age range	Part I	Part II	Response rated
I. Low and lower-middle income countries
Colombia	NSMH	All urban areas of the country (approximately 73% of the total national population).	2003	18–65	4426	2381	87.7
Nigeria	NSMHW	21 of the 36 states in the country, representing 57% of the national population. The surveys were conducted in Yoruba, Igbo, Hausa, and Efik languages.	2002–2004	18–100	6752	2143	79.3
PRCe – Beijing/Shanghai	B-WMH/S-WMH	Beijing and Shanghai metropolitan areas.	2001–2003	18–70	5201	1628	74.7
Peru	EMSMP	Five urban areas of the country (approximately 38% of the total national population).	2004–2005	18–65	3930	1801	90.2
Ukraine	CMDPSD	Nationally representative.	2002	18–91	4724	1719	78.3
TOTAL					(25,033)	(9672)	81.0
II. Upper-middle income countries
Brazil – São Paulo	São Paulo Megacity	São Paulo metropolitan area.	2005–2008	18–93	5037	2942	81.3
Bulgaria	NSHS	Nationally representative.	2002–2006	18–98	5318	2233	72.0
Colombia – Medelling	MMHHS	Medellin metropolitan area.	2011–2012	19–65	3261	1673	97.2
Lebanon	LEBANON	Nationally representative.	2002–2003	18–94	2857	1031	70.0
Mexico	M-NCS	All urban areas of the country (approximately 75% of the total national population).	2001–2002	18–65	5782	2362	76.6
Romania	RMHS	Nationally representative.	2005–2006	18–96	2357	2357	70.9
South Africaf	SASH	Nationally representative.	2002–2004	18–92	4315	4315	87.1
TOTAL					(28,927)	(16,913)	78.5
III. High-income countries
Australiaf	NSMHWB	Nationally representative.	2007	18–85	8463	8463	60.0
Belgium	ESEMeD	Nationally representative. The sample was selected from a national register of Belgium residents.	2001–2002	18–95	2419	1043	50.6
France	ESEMeD	Nationally representative. The sample was selected from a national list of households with listed telephone numbers.	2001–2002	18–97	2894	1436	45.9
Germany	ESEMeD	Nationally representative.	2002–2003	19–95	3555	1323	57.8
Israel	NHS	Nationally representative.	2003–2004	21–98	4859	4859	72.6
Italy	ESEMeD	Nationally representative. The sample was selected from municipality resident registries.	2001–2002	18–100	4712	1779	71.3
Japan	WMHJ	Eleven metropolitan areas.	2002–2006	20–98	4129	1682	55.1
Netherlands	ESEMeD	Nationally representative. The sample was selected from municipal postal registries.	2002–2003	18–95	2372	1094	56.4
New Zealandf	NZMHS	Nationally representative.	2004–2005	18–98	12,790	7312	73.3
Northern Ireland	NISHS	Nationally representative.	2005–2008	18–97	4340	1986	68.4
Portugal	NMHS	Nationally representative.	2008–2009	18–81	3849	2060	57.3
Spain	ESEMeD	Nationally representative.	2001–2002	18–98	5473	2121	78.6
Spain – Murcia	PEGASUS- Murcia	Murcia region. Regionally representative.	2010–2012	18–96	2621	1459	67.4
USA	NCS-R	Nationally representative.	2001–2003	18–99	9282	5692	70.9
TOTAL					(71,758)	(42,309)	64.8
IV. TOTAL					(125,718)	(68,894)	70.4

^aWorld Bank (2012) Data. Retrieved from http://data.worldbank.org/country. 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. The current income category of each country is available at the preceding URL.

^bNSMH (The Colombian National Study of Mental Health); NSMHW (The Nigerian Survey of Mental Health and Wellbeing); B-WMH (The Beijing World Mental Health Survey); S-WMH (The 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); MMHHS (Medellín Mental Health Household Study); LEBANON (Lebanese Evaluation of the Burden of Ailments and Needs of the Nation); M-NCS (The Mexico National Comorbidity Survey); RMHS (Romania Mental Health Survey); SASH (South Africa Health Survey); NSMHWB (National Survey of Mental Health and Wellbeing); ESEMeD (The European Study Of The Epidemiology Of Mental Disorders); NHS (Israel National Health Survey); WMHJ 2002–2006 (World Mental Health Japan Survey); NZMHS (New Zealand Mental Health Survey); NISHS (Northern Ireland Study of Health and Stress); NMHS (Portugal National Mental Health Survey); PEGASUS-Murcia (Psychiatric Enquiry to General Population in Southeast Spain-Murcia);NCS-R (The US National Comorbidity Survey Replication).

^cMost WMH Surveys are based on stratified multistage clustered area probability household samples in which samples of areas equivalent to counties or municipalities in the US 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, Spain-Murcia) used municipal or universal health-care registries to select respondents without listing households. The Japanese sample is the only totally un-clustered sample, with households randomly-selected in each of the 11 metropolitan areas and one random respondent selected in each sample household: 17 of the 27 surveys are based on nationally representative household samples.

^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%

^ePeople’s Republic of China.

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

^gColombia moved from the ‘lower and lower-middle income’ to the ‘upper-middle income’ category between 2003 (when the Colombian National Study of Mental Health was conducted) and 2010 (when the Medellin Mental Health Household Study was conducted), hence Colombia’s appearance in both income categories. For more information, please see footnote ^a.