Table 1.

WMH sample characteristics by World Bank income categories

	Surveya	Sample characteristicsb	Field dates	Age range	Sample size		Response rated
					Part I	Part IIc
I. High-income countries
Belgium	ESEMeD	Nationally representative. The sample was selected from a national register of Belgium residents	2001–2002	18–95	2419	486	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	727	45.9
Germany	ESEMeD	Nationally representative	2002–2003	19–95	3555	621	57.8
Italy	ESEMeD	Nationally representative. The sample was selected from municipality resident registries	2001–2002	18–100	4712	853	71.3
Netherlands	ESEMeD	Nationally representative. The sample was selected from municipal postal registries	2002–2003	18–95	2372	516	56.4
Northern Ireland	NISHS	Nationally representative	2004–2007	18–97	4340	907	68.4
Poland	EZOP	Nationally representative	2010–2011	18–65	10,081	2276	50.4
Portugal	NMHS	Nationally representative	2008–2009	18–81	3849	1070	57.3
Spain	ESEMeD	Nationally representative	2001–2002	18–98	5473	960	78.6
Spain—Murcia	PEGASUS-Murcia	Murcia region	2010–2012	18–96	2621	631	67.4
USA	NCS-R	Nationally representative	2002–2003	18–99	9282	3197	70.9
Total					(51,598)	(12,244)	60.7
II. Upper-middle-income countries
Brazil—São	São Paulo	São Paulo metropolitan area	2005–2007	18–93	5037	1824	81.3
Paulo	Megacity
Colombia—Medellinf	MMHHS	Medellin metropolitan area	2011–2012	19–65	3261	970	97.2
Lebanon	LEBANON	Nationally representative	2002–2003	18–94	2857	595	70.0
Mexico	M-NCS	All urban areas of the country (approximately 75% of the total national population)	2001–2002	18–65	5782	1736	76.6
Romania	RMHS	Nationally representative	2005–2006	18–96	2357	940	70.9
Total					(19,294)	(6065)	78.7
III. Low-/lower-middle-income countries
Colombia	NSMH	All urban areas of the country (approximately 73% of the total national population)	2003	18–65	4426	1731	87.7
Iraq	IMHS	Nationally representative	2006–2007	18–96	4332	3227	95.2
Peru	EMSMP	All urban areas of the country	2004–2005	18–65	3930	1287	90.2
PRCe—Shenzheng	Shenzhen	Shenzhen metropolitan area. Included temporary residents as well as household residents	2006–2007	18–88	7132	2190	80.0
Total					(19,820)	(8435)	86.7
IV. Total					(90,712)	(26,744)	68.5

The World Bank (2012) Data. Accessed May 12, 2012 at: 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

^aNSMH (The Colombian National Study of Mental Health); IMHS (Iraq Mental Health Survey); EMSMP (La Encuesta Mundial de Salud Mental en el Peru); 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); ESEMeD (The European Study Of The Epidemiology Of Mental Disorders); NISHS (Northern Ireland Study of Health and Stress); EZOP (Epidemiology of Mental Disorders and Access to Care Survey); 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)

^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. 13 of the 20 surveys are based on nationally representative household samples

^cIraq and Romania did not have a Part II sample and the N represents their Part I sample with an age ≤ 44 restriction. All other countries were age restricted to ≤44 in the Part II sample

^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 68.5%

^ePeople’s Republic of China

^fColombia moved from the “low-/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 the first note under table regarding The World Bank

^gFor the purposes of cross-national comparisons, we limit the sample to those 18+