Caribbean studies - Schizophrenia

The remaining incidence studies were conducted in Caribbean countries not plainly representative of developing countries. The level of socioeconomic development in the three Caribbean countries is relatively high for the developing world.

Based on the United Nations Development Programme (1998), Barbados ranked 2nd,  Trinidad 13th,  and Jamaica 45th highest among developing nations.  The health indicators and standards of living for these countries may be considered intermediate on the development continuum.

The three Caribbean studies (Hickling and Rodgers-Johnson, 1995; Bhugra et al., 1996; Mahy et al., 1999) emulated the design used in the WHO Ten Country Study: all patients making first contact with care agencies for a possible schizophrenic episode during a 1-year period were assessed for schizophrenia. The rates per 10000 person-years at risk for narrowly defined schizophrenia (CATEGO S+) were 2.1 (Jamaica), 1.6 (Trinidad) and 2.8 (Barbados).

For schizophrenia using a broad CATEGO definition,  the rates per 10000 were 2.4 (SPO schizophrenia, Jamaica),  2.2 (SPO+  schizophrenia,Trinidad)  and 3.2 (SPO+  schizophrenia, Barbados). It should be noted that the rates for the narrow and broad diagnoses are quite similar, as there were few non-S+ cases reported by these sites. Relative to findings in the Ten Country Study, the point estimates for CATEGO S+ incidence rates in the Caribbean countries (range 1.6 - 2.8 per 10000) were higher than those reported at any Ten Country Study site (range 0.7 - 1.4 per 10000). For schizophrenia broadly defined using equivalent diagnostic classifications (SPO, SPO+) the Caribbean rates are higher than those reported by the WHO study developed country sites, except Moscow, and similar to those reported by developing country sites.

What does the total evidence suggest about variation in incidence of schizophrenia between developing and developed countries? Clearly there are insuficient data to support the claim that there is no difference in incidence between these two settings.

However, the existing evidence is also insuficient for any inference of systematic variation across developing and developed countries. In sum, a strong case can be made for variation in incidence across place, but a patterned distribution based on country level of development is inconclusive.

Nonaffective acute remitting psychosis

It would be wrong, however, to conclude that no evidence has emerged from incidence studies relating to systematic variation in any nonaffective psychoses between developing and developed countries. Susser and collaborators found evidence for a distinct nonaffective psychotic disorder that mainly occurs in the developing world.  Susser and Wanderling (1994)  reported a marked variation in incidence of nonaffective acute remitting psychosis (NARP)  between developed and developing country settings. The incidence of NARP was 10-fold greater in the developing than developed country settings in the Ten Country Study.

Susser and colleagues have argued that such results support the idea of a distinct disorder. Biological as well as cultural influences are suspected in the aetiology of these psychotic disorders (Collins et al., 1996, 1999). In one study, patients with NARP were more likely to have experienced fever in the 12 weeks preceding onset than controls (odds ratio 6.2).

Moreover,  this class of remitting psychotic disorders constitutes a potential source of misclassified cases in studies of schizophrenia. In fact, all patients with NARP that Susser and Wanderling (1994) identified had been diagnosed, by their definition of NARP, with ICD-9 schizophrenia. The influence of NARP on incidence rates of schizophrenia,  however,  does not explain most of the difference between developed and developing countries in the incidence of schizophrenia broadly defined in the Ten Country Study, or the differential in incidence suspected based on the preliminary data on ICD-10 schizophrenia.  Differences remained after removing those with NARP.

Some other differences between developing and developed countries remain unexplained. In particular, differences in the frequencies of psychotic individuals diagnosed as catatonic in the Ten Country Study (10% in developing countries and extremely rare in developed countries) have not been accounted for. Together with the finding of high rates of NARP in developing country settings, the evidence suggests possible aetiologic and disease diversity across the developing/developed

Michaeline Bresnahan, Paulo Menezes, Vijoy Varma and Ezra Susser
Division of Epidemiology, Columbia University, New York, USA
Department of Preventative Medicine, University of Sao Paulo, Brazil


  • Bamrah JS, Freeman HL, Goldberg DP (1991) Epidemiology of schizophrenia in Salford, 1974 - 84. Changes in an urban community over ten years. British Journal of Psychiatry 159, 802 - 810.
  • Bell MD, Lysaker PH (1997) Clinical benefits of paid work activity in schizophrenia: one year follow-up. Schizophrenia Bulletin 23, 317 - 328.
  • Bhugra D, Hilwig M, Hossein B et al. (1996) First-contact incidence rates of schizophrenia in Trinidad and one-year follow-up. British Journal of Psychiatry 169, 587 - 592.
  • Bhugra D, Leff J, Mallett R, Der G, Corridau B, Rudge S (1997) Incidence and outcome of schizophrenia in whites, African Caribbeans and Asians in London. Psychological Medicine 27, 791 - 798.
  • Bresnahan MA, Brown AS, Schaefer CA, Begg MD, Wyatt RJ, Susser ES (2000) Incidence and cumulative risk of treated schizophrenia in the Prenatal Determinants of Schizophrenia study. Schizophrenia Bulletin 26, 297 - 308.
  • Brewin J, Cantwell R, Dalkin T et al. (1997) Incidence of schizophrenia in Nottingham. A comparison of two cohorts, 1978 - 80 and 1992 - 94. British Journal of Psychiatry 171, 140 - 144.
  • Brown GH, Bone M, Dalison B, Wing JK (1966) Schizophrenia and Social Care. London: Oxford University Press.
  • Carpenter WT, Strauss JS (1991) The prediction of outcome in schizophrenia IV: Eleven-year follow-up of the Washington IPSS cohort. Journal of Nervous and Mental Disease 179, 517 - 525.
  • Collins PY, Wig NN, Day R et al. (1996) Psychosocial and biological aspects of acute brief psychoses in three developing country sites. Psychiatric Quarterly 67, 177 - 193.
  • Collins PY, Varma VK, Wig NN, Mojtabai R, Day R, Susser E (1999) Fever and acute brief psychosis in urban and rural settings in north India. British Journal of Pyschiatry 173, 520 - 524.
  • d'Arcy C, Rawson NSB, Lydick E, Epstein R (1993) The Epidemiology of Treated Schizophrenia
  • Saskatchewan 1976 - 1990. Gronigen, the Netherlands: World Psychiatric Association, Section of Epidemiology and Community Psychiatry.
  • Dube KC, Kumar N, Dube S (1984) Long term course and outcome of the Agra cases in the International Pilot Study of Schizophrenia. Acta Psychiatrica Scandinavica 70, 170 - 179.
  • Eaton WW (1999) Evidence for universality and uniformity of schizophrenia around the world: assessment and implications. In Search for the Causes of Schizophrenia, Vol. IV: Balance of the Century, WF Gattaz and H Hafner, eds. Berlin: Springer-Verlag, pp. 21 - 33.
  • German N (1972) Aspects of clinical psychiatry in sub-Saharan Africa. British Journal of Psychiatry 121, 461 - 479.
  • Goater N, King M, Cole E et al. (1999) Ethnicity and outcome of psychosis. British Journal of Psychiatry 175, 34 - 42.
  • Harrison G, Mason P, Glazebrook C, Medley I, Croudace T, Docherty S (1994) Residence of incident cohort of psychotic patients after 13 years of follow up. British Medical Journal 308, 813 - 816.
  • Harrison G, Croudace T, Mason P, Glazebrook C, Medley I (1996) Predicting the long-term outcome of schizophrenia. Psychological Medicine 26, 697 - 705.
  • Helgason L (1990) Twenty years' follow-up of first psychiatric presentation for schizophrenia: what could have been prevented? Acta Psychiatrica Scandinavica 81, 231 - 235.
  • Hickling FW, Rodgers-Johnson P (1995) The incidence of first contact schizophrenia in Jamaica. British Journal of Psychiatry 167, 193 - 196.
  • Hopper K, Wanderling J (2000) Revisiting the developed versus developing country distinction in course and outcome in schizophrenia: Results from ISoS, the WHO colloaborative follow-up project. Schizophrenia Bulletin 26, 835 - 846.
  • Iancano WG, Beiser M (1992) Are males more likely than females to develop schizophrenia? American Journal of Psychiatry 149, 1070 - 1074.
  • Jablensky A, Sartorius N, Ernberg G et al. (1992) Schizophrenia: manifestations, incidence and course in different cultures. Psychological Medicine, Monograph Supplement 20. Cambridge: Cambridge University Press.
  • Kulhara P, Wig NN (1978) The chronicity of schizophrenia in North West India: results of a follow-up study. British Journal of Psychiatry 132, 186 - 190.
  • Lambo TA (1960) Further neuropsychiatric observations in Nigeria. British Medical Journal 2, 1696 - 1704.
  • Lee PWH, Lieh-Mak F, Wong MC, Fung ASM, Mak KY, Lam J (1998) The 15-year outcome of Chinese patients with schizophrenia in Hong Kong. Canadian Journal of Psychiatry 43, 706 - 713.
  • Leff J, Wig NN, Gosh A et al. (1987) Influence of relatives' expressed emotion on the course of schizophrenia in Chandigarh. British Journal of Psychiatry 151, 166 - 173.
  • Leff J, Sartorius N, Jablensky A, Korten A, Ernberg G (1992) The International Pilot Study of Schizophrenia: five year follow-up findings. Psychological Medicine 22, 131 - 145.
  • Leon CA (1989) Clinical course and outcome of schizophrenia in Cali, Columbia: a 10-year follow-up study. Journal of Nervous and Mental Disease 177, 593 - 606.
  • Lo WH, Lo T (1977) A ten-year follow-up study of Chinese schizophrenics in Hong Kong. British Journal of Psychiatry 131, 63 - 66.
  • Mahy G, Mallett R, Leff J, Bhugra D (1999) First-contact incidence rate of schizophrenia on Barbados. British Journal of Psychiatry 175, 28 - 33.
  • Mason P, Harrison G, Glazebrook C, Medley I, Dalkin T, Croudace T (1995) Characteristics of outcome in schizophrenia at 13 years. British Journal of Psychiatry 167, 596 - 603.
  • Mason P, Harrison G, Glazebrook C Medley, I Croudace T (1996) The course of schizophrenia over 13 years. A report from the International Study on Schizophrenia (ISoS) coordinated by the World Health Organization (1996) British Journal of Psychiatry 169, 580 - 586.
  • Mason P, Harrison G, Croudace T, Glazebrook C, Medley I (1997) The predictive validity of a diagnosis of schizophrenia. British Journal of Psychiatry 178, 321 - 327.
  • Menezes PR, Mann AH (1996) Mortality among patients with nonaffective functional psychoses in the city of Sao Paulo. Revista de Saude Publica 30, 304 - 309.
  • Mojtabai R, Varma VK, Malhotra S et al. (2001) Mortality and long-term course in schizophrenia with a 2-year poor course: a study in a developing country. British Journal of Psychiatry 178, 71 - 75.
  • Murphy HBM, Raman AC (1971) The chronicity of schizophrenia in indigenous tropical peoples: results of a twelve-year follow-up survey. British Journal of Psychiatry 118, 489 - 497.
  • Ninulaain M, O'Hare A, Walsh D (1987) Incidence of schizophrenia in Ireland. Psychological Medicine 17, 943 - 948.
  • Rajkumar S, Padmavati R, Thara R, Sarada Menon M (1993) Incidence of schizophrenia in an urban community in Madras. Indian Journal of Psychiatry 35, 18 - 21.
  • Rin H, Lin TY (1962) Mental illness among Formosan Aborigines as compared with the Chinese in Taiwan. Journal of Mental Science 108, 134 - 146.
  • Sartorius N, Jablensky A, Korten A et al. (1986) Early manifestations and first-contact incidence of schizophrenia in different cultures. Psychological Medicine 16, 909 - 928.
  • Scottish Schizophrenia Research Group (1992) The Scottish first episode schizophrenia study VIII. Five-year follow-up: clinical and psychosocial findings. British Journal of Psychiatry 161, 496 - 500.
  • Shepherd M, Watt D, Falloon I, Smeeton N (1983) The natural history of schizophrenia: a five year follow-up study of outcome and prediction in a representative sample of schizophrenics. Psychological Medicine, Monograph Supplement 15. Cambridge: Cambridge University Press.
  • Susser E, Wanderling J (1994) Epidemiology of nonaffective acute remitting psychosis vs schizophrenia. Archives General Psychiatry 51, 294 - 301.
  • Susser E, Collins P, Schanzer B, Varma VK, Gittelman M (1996) Can we learn from the care of persons with mental illness in developing countries? American Journal of Public Health 86, 926 - 928.
  • Susser E, Varma VK, Mattoo SK et al. (1998) Long-term course of acute brief psychosis in a developing country setting. British Journal of Psychiatry 173, 226 - 230.
  • Thara R, Henrietta M, Joseph, A, Rajkumar S, Eaton WW (1994) Ten-year course of schizophrenia - the Madras longitudinal study. Acta Psychiatrica Scandinavica 90, 329 - 336.
  • Tsoi WF, Wong KE (1991) A 15-year follow-up study of Chinese schizophrenic patients. Acta Psychiatrica Scandinavica 84, 1248 - 1253.
  • United Nations Development Programme (1998) Human Development Report. New York: United Nations.
  • Vazquez-Barquero JL, Cuesta Nunez MJ, de la Varga M et al. (1995) The Cantabria first episode schizophrenia study: a summary of general findings. Acta Psychiatrica Scandinavica 91, 156 - 162.
  • Warner R (1985) Recovery from Schizophrenia: Psychiatry and Political Economy. London: Routledge & Kegan Paul.
  • Waxler NE (1979) Is outcome for schizophrenia better in non-industrial societies? The case of Sri Lanka. Journal of Nervous and Mental Disease 167, 144 - 158.
  • Wig NN, Menon DK, Bedi H et al. (1987) Distribution of expressed emotion component in relatives of schizophrenic patients in Aarhus and Chandigarh. British Journal of Psychiatry 151, 160 - 165.
  • Wiersma D, Nienhuis FJ, Sloott CJ, Giel R (1998) Natural course of schizophrenic disorders: a 15-year follow-up of a Dutch incidence cohort. Schizophrenia Bulletin 24, 75 - 85.
  • World Health Organization (1973) The International Pilot Study of Schizophrenia. Vol. 1. Geneva: World Health Organization.
  • World Health Organization (1979) Schizophrenia: An International Follow-up Study. Chichester, UK: Wiley.
  • World Health Organization (1992) Manual of International Statistical Classification of Diseases, Injuries and Causes of Death, 10th edn. Geneva: World Health Organization.

Provided by ArmMed Media