Marie-José Dealberto dealbert at queensu.ca
Department of Community Health and Epidemiology, Carruthers Hall, Queen's University, Kingston, Ontario, Canada K7L 3N6
Psychiatry Research Received 3 March 2012; received in revised form 26 September 2012; accepted 9 January 2013. published online 25 February 2013.
Two major risk factors for schizophrenia are present in Canada, high latitude and a large and growing immigrant population. Consequently, one would expect unusually high rates of schizophrenia and an increase in these rates over time. This systematic review tests these two hypotheses. Searches of electronic databases were performed through 2011. Out of 45 studies 12 fulfilled all the inclusion criteria. The means of Canadian and international rates were compared by one-tailed unequal variance t-test. Trends with time in Canadian rates were tested by the Spearman rank correlation coefficient.
Prevalence and incidence rates in Canada were significantly higher than those in international studies. Rates increased over time, with a significant increase for prevalence and a trend for incidence. This rise was supported by historical data, recent hospital admission data, and the only Canadian cohort study. The findings of elevated rates in Canada and their increase over time give concern due to the serious personal, social, and financial burden of schizophrenia. These results, based on a small number of studies, warrant confirmation by specially designed studies. They could explain the discrepant results of the risk associated with immigration in Canadian studies.
Preliminary results were presented in an oral presentation: ‘Are rates for schizophrenia unusually high in Canada?’ at the Psychotic Disorders Section, 60th Canadian Psychiatric Association Conference, Toronto, September 23–26, 2010.
References are at the bottom of this page
- Overview Schizophrenia and Vitamin D which has the following summary Feb 2013:
- (Vitually) all patients with schizophrenia are vitamin D deficient
- Schizophrenia varies with latitude (UVB) by 10X (controversy)
- Schizophrenia is more common in those with dark skin (when away from the equator)
- Schizophrenia has been increasing around the world when vitamin D has been decreasing (controversy)
- Schizophrenia is associated with low natal vitamin D
- Schizophrenia is associated with low birth rate, which is associated with low vitamin D
- Schizophrenia is associated with Autism which is associated with low vitamin D
- Vitamin D, light and mental health file
- Psychosis in dark skinned people 3.5 X higher if low level of vitamin D – May 2012
- Overview Pregnancy and vitamin D
400 IU of vitamin D for mother-to-be ==> 3X less adolescent Schizophrenia
- All items in Winter Blues and Vitamin D _
- SAD rate 10X higher in cloudy Seattle than sunny Florida - April 2011
Anticipate higher rate of Schizophrenia in Seattle as well - but have not found the data so far
- Infants 2X more likely to get schizophrenia if had very low vitamin D – Sept 2010
- Schizophrenia and vitamin D have latitude-related genes – Nov 2010 which has the following graphic
Schizophrenia high and increasing in Canada – lower vitamin D and more dark skin – Feb 2013
- Bhugra D, Hilwig M, Hossein B, Marceau H, Neehall J, Leff J, et al. First-contact incidence rates of schizophrenia in Trinidad and one-year follow-up. British Journal of Psychiatry. 1996;169:587–592
- Bland RC. Demographic aspects of functional psychoses in Canada. Acta Psychiatrica Scandinavica. 1977;55:369–380
- Bland RC. Long term mental illness in Canada: an epidemiological perspective on schizophrenia and affective disorders. Canadian Journal of Psychiatry. 1984;29:242–246
- Bland RC, Orn H. Schizophrenia: sociocultural factors. Canadian Journal of Psychiatry. 1981;26:186–188
- Bland RC, Orn H, Newman SC. Lifetime prevalence of psychiatric disorders in Edmonton. Acta Psychiatrica Scandinavica Supplementum. 1988;338:24–32
- Bland RC, Parker JH, Orn H. Prognosis in schizophrenia. A ten-year follow-up of first admissions. Archives of General Psychiatry. 1976;33:949–954
- Bourque F, van der Ven E, Malla A. A meta-analysis of the risk for psychotic disorders among first- and second-generation immigrants. Psychological Medicine. 2011;41:897–910
- Bray I, Waraich P, Jones W, Slater S, Goldner EM, Somers J. Increase in schizophrenia incidence rates: findings in a Canadian cohort born 1975–1985. Social Psychiatry and Psychiatric Epidemiology. 2006;41:611–618
- Canadian Institute for Health Information, 2003. Hospital Mental Health Services in Canada 2000–2001. http://www.mooddisorderscanada.ca/documents/Publications/Hospital%20Mental%20Health%20Services%20in%20Canada%202001-2002.pdf (accessed 01.09.10).
- Canadian Institute for Health Information, 2005. Hospital Mental Health Services in Canada 2002–2003. http://www.cmha.ca/data/2/rec_docs/446_HospitalMentalHealth_0203_e.pdf (accessed 01.09.10).
- Canadian Institute for Health Information, 2006. Hospital Mental Health Services in Canada 2003–2004. http://secure.cihi.ca/cihiweb/products/HMHDB_2003-2004_e.pdf (accessed 01.09.10).
- Canadian Institute for Health Information, 2007. Hospital Mental Health Services in Canada 2004–2005. http://secure.cihi.ca/cihiweb/products/HMHSC_2005_e.pdf (accessed 01.09.10).
- Canadian Institute for Health Information, 2008. Hospital Mental Health Services in Canada 2005–2006. http://secure.cihi.ca/cihiweb/products/HMHDB_annual_report_2008e.pdf (accessed 01.09.10).
- Canadian Institute for Health Information, 2011. Hospital Mental Health Services in Canada 2009–2010. http://secure.cihi.ca/cihiweb/products/health_indicators_2011_en.pdf (accessed 15.07.11).
- Cantor-Graae E, Selten JP. Schizophrenia and migration: a metaanalysis and review. American Journal of Psychiatry. 2005;162:12–24
- Chui, T., Tran, K., Maheux, H., 2007. Immigration in Canada: A Portrait of the Foreign-Born Population, 2006 Census. Statistics Canada 2007. http://12.statcan.ca/census-recensement/2006/as-sa/97–557/pdf/97–557-XIE2006001.pdf (accessed 01.09.10).
- De Hesse, C., 1967. Migration and Mental Illness. A Study of First Admission Rates for Functional Psychoses Among the Foreign-Born and Native-Born Populations in Canada. Ph.D. Thesis. Ottawa, ON, Carleton University.
- Dealberto MJ. Ethnic origin and increased risk for schizophrenia in immigrants to countries of recent and longstanding immigration. Acta Psychiatrica Scandinavica. 2010;121:325–339
- Dealberto MJ, Middlebro A, Farrell S. Symptoms of schizophrenia and psychosis according to foreign birth in a Canadian sample of homeless persons. Psychiatric Services. 2011;62:1187–1193
- Dealberto, M.J., 2012. Are Immigrants to Canada at Increased or Decreased Risk for Schizophrenia? In: Proceedings of the Third Biennal Schizophrenia International Research Society Conference, 14–18 April 2012, Florence, Italy.
- Dowbiggin IR. Keeping America Sane Psychiatry and Eugenics in the United States and Canada, 1880–1940. Ithaca, NY: Cornell University Press; 1997;
- Goldner EM, Hsu L, Waraich P, Somers JM. Prevalence and incidence studies of schizophrenic disorders: a systematic review of the literature. Canadian Journal of Psychiatry. 2002;47:833–843
- Goldner EM, Jones W, Waraich P. Using administrative data to analyze the prevalence and distribution of schizophrenic disorders. Psychiatric Services. 2003;54:1017–1021
- Hanoeman M, Selten JP, Kahn RS. Incidence of schizophrenia in Surinam. Schizophrenia Research. 2002;54:219–221
- Hickling FW, Rodgers-Johnson P. The incidence of first contact schizophrenia in Jamaica. British Journal of Psychiatry. 1995;167:193–196
- Iacono WG, Beiser M. Are males more likely than females to develop schizophrenia?. American Journal of Psychiatry. 1992;149:1070–1074
- Kinney DK, Teixeira P, Hsu D, Napoleon SC, Crowley D, Miller A, et al. Relation of schizophrenia prevalence to latitude, climate, fish consumption, infant mortality, and skin color: a role for prenatal vitamin D deficiency and infections. Schizophrenia Bulletin. 2009;35:582–595
- Mahy GE, Mallett R, Leff J, Bhugra D. First-contact incidence rate of schizophrenia on Barbados. British Journal of Psychiatry. 1999;175:28–33
- Malzberg B. Mental Disease Among Native and Foreign-Born in Canada 1950–1952. Albany, NY: Research Foundation for Mental Hygiene; 1963;
- McDermott, S., Dealberto, M.J., DesMeules, M., Kazanjian, A., Manuel, D., Ruddick, E., Vissandjee, B., 2007. Psychoses-related acute hospital discharges among immigrants arriving to Canada between 1985 and 2000: a linkage follow up study using administrative data. In: Proceedings of the Canadian Academy of Psychiatric Epidemiology Conference, 15 November 2007, Montreal, Quebec.
- McGrath J. Hypothesis: is low prenatal vitamin D a risk-modifying factor for schizophrenia?. Schizophrenia Research. 1999;40:173–177
- McGrath J, Saha S, Welham J, El Saadi O, MacCauley C, Chant D. A systematic review of the incidence of schizophrenia: the distribution of rates and the influence of sex, urbanicity, migrant status and methodology. BMC Medicine. 2004;2:13
- Menezes NM, Georgiades K, Boyle MH. The influence of immigrant status and concentration on psychiatric disorder in Canada: a multi-level analysis. Psychological Medicine. 2011;41:2221–2231
- Morgan P, Andrushko E. The use of diagnosis-specific rates of mental hospitalization to estimate underutilization by immigrants. Social Science and Medicine. 1977;11:611–618
- Nicole L, Lesage A, Lalonde P. Lower incidence and increased male:female ratio in schizophrenia. British Journal of Psychiatry. 1992;161:556–557
- Nimgaonkar VL, Fujiwara TM, Dutta M, Wood J, Gentry K, Maendel S, et al. Low prevalence of psychoses among the Hutterites, an isolated religious community. American Journal of Psychiatry. 2000;157:1065–1070
- Ontario Public Health Association, 2000. Report of the Health Status of the Residents of Ontario. http://www.opha.on.ca/resources/docs/healthstatus/english/chapter11.pdf (accessed 01.09.10).
- Randhawa J, Riley R. Mental health statistics, 1982–83 to 1993–94. Health Reports. 1996;7:55–61
- Rawson NS, Malcolm E, D'Arcy C. Reliability of the recording of schizophrenia and depressive disorder in the Saskatchewan health care datafiles. Social Psychiatry and Psychiatric Epidemiology. 1997;32:191–199
- Rhodes A, Agha M, Creatore M, Glazier R. Monitoring mental health reform in a Canadian inner city. Health and Place. 2004;10:163–168
- Saha S, Chant D, Welham J, McGrath J. A systematic review of the prevalence of schizophrenia. PLoS Medicine. 2005;2:e141
- Saha S, Chant DC, Welham JL, McGrath J. The incidence and prevalence of schizophrenia varies with latitude. Acta Psychiatrica Scandinavica. 2006;14:36–39
- Selten JP, Zeyl C, Dwarkasing R, Lumsden V, Kahn RS, Van Harten PN. First-contact incidence of schizophrenia in Surinam. British Journal of Psychiatry. 2005;186:74–75
- Smith GN, Boydell J, Murray RM, Flynn S, McKay K, Sherwood M, et al. The incidence of schizophrenia in European immigrants to Canada. Schizophrenia Research. 2006;87:205–211
- Statistics Canada, 2006. Census 2006. http://www.12statcan.ca/ (accessed 01.09.10).
- Stoll AL, Tohen M, Baldessarini RJ, Goodwin DC, Stein S, Katz S, et al. Shifts in diagnostic frequencies of schizophrenia and major affective disorders at six North American psychiatric hospitals, 1972–1988. American Journal of Psychiatry. 1993;150:1668–1673
- Stroup DF, Berlin JA, Morton SC, Olkin I, Williamson GD, Rennie D, et al. Meta-analysis of observational studies in epidemiology: a proposal for reporting Meta-analysis of observational studies in epidemiology (MOOSE) group. Journal of the American Medical Association. 2000;283:2008–2012
- Suvisaari JM, Haukka JK, Tanskanen AJ, Lönnqvist JK. Decline in the incidence of schizophrenia in Finnish cohorts born from 1954 to 1965. Archives of General Psychiatry. 1999;56:733–740
- Torrey EF. Prevalence studies in schizophrenia. British Journal of Psychiatry. 1987;150:598–608
- Torrey EF. Prevalence of psychosis among the Hutterites: a reanalysis of the 1950–53 study. Schizophrenia Research. 1995;16:167–170
- Torrey EF, Miller J. The Invisible Plague: The Rise of Mental Illness From 1750 to the Present Piscataway. NJ: Rutgers University Press; 2001;
- Vanasse A, Courteau J, Fleury MJ, Grégoire JP, Lesage A, Moisan J. Treatment prevalence and incidence of schizophrenia in Quebec using a population health services perspective: different algorithms, different estimates. Social Psychiatry and Psychiatric Epidemiology. 2012;47:533–543
- Woogh C. Is schizophrenia on the decline in Canada?. Canadian Journal of Psychiatry. 2001;46:61–67
7547 visitors, last modified 28 Feb, 2013,
- SAD rate 10X higher in cloudy Seattle than sunny Florida - April 2011