{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,12]],"date-time":"2026-09-12T06:06:08Z","timestamp":1789193168673,"version":"build-2803163510"},"reference-count":26,"publisher":"SAGE Publications","issue":"7","license":[{"start":{"date-parts":[[2002,9,1]],"date-time":"2002-09-01T00:00:00Z","timestamp":1030838400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Can J Psychiatry"],"published-print":{"date-parts":[[2002,9]]},"abstract":"<jats:sec>\n                    <jats:title>Objectives:<\/jats:title>\n                    <jats:p>There are few Canadian prevalence studies of mental retardation (MR); those that do exist were conducted prior to the era of community integration. We undertook a population-based study to explore mental health disturbances in young persons with MR. The first requirement was to identify a population with MR and to establish its prevalence. Here, we report data on the prevalence of MR in a population aged 14 to 20 years.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Method:<\/jats:title>\n                    <jats:p>We conducted the study in the Niagara Region of Ontario, which has a population base of around 400 000. Researchers worked closely with schools and with agencies providing services to persons with MR to identify the study group. We confirmed the functioning level of participants through standard tests of nonverbal intelligence and receptive language; teachers and other service personnel provided information relevant to the estimation of nonparticipants' functioning level.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results:<\/jats:title>\n                    <jats:p>We identified 255 individuals as having MR (IQ \u2264 75). Of these, 171 chose to participate (defined as \u201cparticipants with MR\u201d; the remaining 84 were \u201cnonparticipants with MR\u201d). Thus, the participation rate was 67% (171\/255). Participants and nonparticipants with MR did not differ on age, sex, or IQ, although there were more nonparticipants in the lower social strata. Overall prevalence for MR was 7.18\/1000. For mild mental retardation (MMR; that is, IQ = 50 to 75), prevalence was 3.54\/1000, and for severe mental retardation (SMR; that is, IQ &lt; 50), it was 3.64\/1000.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions:<\/jats:title>\n                    <jats:p>Our prevalence estimate for SMR is similar to rates from previous studies conducted worldwide. Our estimate for MMR parallels the lower rates found in Scandinavian countries and contrasts with the higher rates generally reported in the US.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/070674370204700707","type":"journal-article","created":{"date-parts":[[2017,7,20]],"date-time":"2017-07-20T01:41:32Z","timestamp":1500514892000},"page":"652-659","source":"Crossref","is-referenced-by-count":22,"title":["Mental Retardation in Teenagers: Prevalence Data from the Niagara Region, Ontario"],"prefix":"10.1177","volume":"47","author":[{"given":"Elspeth A","family":"Bradley","sequence":"first","affiliation":[{"name":"Associate Professor, Department of Psychiatry, University of Toronto; Psychiatrist-in-Chief Surrey Place Centre, Toronto, Ontario"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ann","family":"Thompson","sequence":"additional","affiliation":[{"name":"Research Coordinator, Department of Psychiatry, McMaster University, Hamilton, Ontario"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Susan E","family":"Bryson","sequence":"additional","affiliation":[{"name":"Associate Professor, Department of Psychology, York University, Toronto; Associate Scientist, The Hospital for Sick Children, Toronto, Ontario"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2002,9,1]]},"reference":[{"key":"bibr1-070674370204700707","volume-title":"Diagnostic and statistical manual of mental disorders","author":"American Psychiatric Association","year":"1994","edition":"4"},{"key":"bibr2-070674370204700707","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.317.7151.111"},{"key":"bibr3-070674370204700707","volume-title":"Burdens of disease: A discussion document","author":"National Health Service Management Executive","year":"1996"},{"key":"bibr4-070674370204700707","volume-title":"Fifteenth report of the WHO Expert Committee on Mental Health.","author":"WHO Expert Committee on Mental Health","year":"1968"},{"key":"bibr5-070674370204700707","volume-title":"Mental retardation: Meeting the challenge","author":"World Health Organization, Joint Commission on International Aspects of Mental Retardation","year":"1985"},{"key":"bibr6-070674370204700707","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-8749.1997.tb07395.x"},{"key":"bibr7-070674370204700707","first-page":"18","volume":"80","author":"Abramowicz HK","year":"1975","journal-title":"American Journal of Mental Deficiency"},{"key":"bibr8-070674370204700707","doi-asserted-by":"publisher","DOI":"10.1111\/j.1600-0447.1989.tb05220.x"},{"key":"bibr9-070674370204700707","first-page":"9","volume":"44","author":"Zigler E.","year":"1987","journal-title":"Ups J Med Sci Suppl"},{"key":"bibr10-070674370204700707","volume-title":"The epidemiology of severe intellectual impairment: The dynamics of prevalence","author":"Fryers T.","year":"1984"},{"key":"bibr11-070674370204700707","first-page":"243","volume":"92","author":"McLaren J","year":"1987","journal-title":"Am J Ment Retard"},{"key":"bibr12-070674370204700707","volume-title":"Twenty-two years: Causes and consequences of mental retardation","author":"Richardson SA","year":"1996"},{"key":"bibr13-070674370204700707","doi-asserted-by":"publisher","DOI":"10.1080\/02674648966780181"},{"key":"bibr14-070674370204700707","first-page":"205","volume":"78","author":"McDonald AD","year":"1973","journal-title":"American Journal of Mental Deficiency"},{"key":"bibr15-070674370204700707","first-page":"460","volume":"91","author":"McQueen PC","year":"1987","journal-title":"American Journal of Mental Deficiency"},{"key":"bibr16-070674370204700707","first-page":"323","volume":"89","author":"Baird PA","year":"1985","journal-title":"American Journal of Mental Deficiency"},{"key":"bibr17-070674370204700707","volume-title":"Population by age group","author":"Statistics Canada, CANSIM","year":"1996"},{"key":"bibr18-070674370204700707","volume-title":"Population of census metropolitan areas","author":"Statistics Canada, CANSIM","year":"1998"},{"key":"bibr19-070674370204700707","volume-title":"Four factor index of social status","author":"de B. Hollingshead A","year":"1975"},{"key":"bibr20-070674370204700707","volume-title":"ICD-10 international statistical classification of diseases and related health problems","author":"World Health Organization","year":"1992","edition":"10"},{"key":"bibr21-070674370204700707","volume-title":"MRC Social Psychiatry Unit","author":"Wing L.","year":"1985"},{"key":"bibr22-070674370204700707","doi-asserted-by":"publisher","DOI":"10.2105\/AJPH.85.3.319"},{"key":"bibr23-070674370204700707","first-page":"19","volume":"44","author":"Kebbon L.","year":"1987","journal-title":"Ups J Med Sci Suppl"},{"key":"bibr24-070674370204700707","first-page":"692","volume":"97","author":"Sonnander K","year":"1993","journal-title":"Am J Ment Retard"},{"key":"bibr25-070674370204700707","volume-title":"From Asylum to welfare","author":"Simmons HG","year":"1982"},{"key":"bibr26-070674370204700707","doi-asserted-by":"publisher","DOI":"10.1111\/j.1651-2227.1979.tb06164.x"}],"container-title":["The Canadian Journal of Psychiatry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/070674370204700707","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/070674370204700707","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T16:13:01Z","timestamp":1777392781000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/070674370204700707"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2002,9]]},"references-count":26,"journal-issue":{"issue":"7","published-print":{"date-parts":[[2002,9]]}},"alternative-id":["10.1177\/070674370204700707"],"URL":"https:\/\/doi.org\/10.1177\/070674370204700707","relation":{},"ISSN":["0706-7437","1497-0015"],"issn-type":[{"value":"0706-7437","type":"print"},{"value":"1497-0015","type":"electronic"}],"subject":[],"published":{"date-parts":[[2002,9]]}}}