Variations in the Prevalence of Psychiatric Disorders and Social Problems Across Canadian Provinces

Transcription

1 CAPE Special Issue Variations in the Prevalence of Psychiatric Disorders and Social Problems Across Canadian Provinces Angus H Thompson, PhD 1 Objective: To determine provincial 12-month prevalence rates for selected psychiatric disorders and to assess the association between these and the Canadian Social Problem Index (SPI). Method: Psychiatric data for depression, mania, panic disorder, social phobia, and agoraphobia were derived from the results of the 2002 Canadian Community Health Survey: Mental Health and Well-Being. The Canadian SPI was updated for 2002, and correlations were calculated between the SPI and the 5 diagnostic prevalence values across provinces. Results: The results showed that the SPI had maintained its tendency to increase from east to west in Canada, a trend reflected by depression and mania. The psychiatric disorders did not show strong correlations with the SPI in 2002, but depression and mania did show relatively strong associations with index values from earlier years. High-to-low ratios across provinces for individual social problems averaged over 5, and the results were essentially of the same magnitude for the ranges of particular psychiatric diagnoses. Conclusions: The differences in need found here suggest that per capita allocation of funding for mental health and social programs may not be appropriate. The mixed findings on the association between mental disorders and social problem behaviour across provinces leads to more research questions than research answers. (Can J Psychiatry 2005;50: ) Information on funding and support and author affiliations appears at the end of the article. Clinical Implications Canadian provinces differ significantly in levels of social problem behaviour and in the prevalence of mental disorders. Per capita allocation of resources may not be appropriate across regions because of differing need. The extent of social problem behaviour may be related to mental illness levels several years earlier. Limitations The CCHS 1.2, while extremely valuable, did not collect data on schizophrenia. Ecologic trends do not show cause and effect. The many differences among provinces indicate that definitive conclusions are ordinarily not possible. The focus should be on the generation of hypotheses. Key Words: mental illness, depression, mania, phobia, panic disorder, social problems, psychiatric epidemiology Can J Psychiatry, Vol 50, No 10, September

2 The Canadian Journal of Psychiatry CAPE Special Issue Arecent Canadian study (1) found that provinces or territories that rank highly on one social problem tend to rank highly on others and that such problems (for example, homicide, attempted murder, sexual assault, assault, robbery, alcoholism, divorce, and suicide) could be parsimoniously described by a single index, namely, the SPI. The provinces have shown an east-to-west gradient with the highest SPI values being found in the west. Significantly higher rates have been found in Canada s northern territories. The level of the SPI has increased steadily over several decades, with a slight recent decrease ( ). A related study has shown that the prevalence of childhood trauma (a consequence of many social problems) has also risen over time, especially for girls (2). Notably, the clustering of social problems is not restricted to geopolitical areas; individuals who exhibit one social problem have an increased likelihood of engaging in other types of social problem behaviours. In a survey of 3258 adults in Edmonton (3), individuals provided information that allowed for the assignment of psychiatric diagnoses (8 core diagnoses were used) and for the assessment of participation in 8 social problem behaviours (that is, drug abuse, unemployment, spouse abuse, child abuse, alcohol abuse, suicidal behaviour, divorce, and felony). The results showed that nearly one-half of those engaging in any social problem behaviour had exhibited 2 or more such behaviours. Further, there was a high level of association between social problems, as a class, with psychiatric disorders, again as a class. Out of 64 possible disorder and social problem pairings, 57 displayed a statistically significant association. That is, any diagnosis is associated with all, or nearly all, social problems. Clinicians had long ago noted the association of psychiatric disorder with various social problem behaviours, and later, this was supported by many clinical studies. However, clinical studies have their shortcomings, primarily the selection bias inherent in any self-directed activity, such as help seeking. Concerns surrounding this issue were set aside with the relatively recent advent of large-scale community studies, which, generally speaking, made it clear that the associations noted in clinical samples held for the general population as well. For example, in Canada, findings from the Edmonton Abbreviations used in this article CCHS 1.2 ECA NS SD SPI 638 Canadian Community Health Survey: Mental Health and Well-Being Epidemiologic Catchment Area not signifcant standard deviation Social Problem Index Table 1 Ratios of the highest to lowest provincial rates for the 8 problems of the SPI Homicide Attempted murder Assault Rape Robbery Divorce Suicide Alcoholism Mean Area Study of Psychiatric Disorders indicated that there are strong associations between mental illness and unemployment (4), suicide attempts (5), spouse and child abuse (6), alcoholism (7), incarceration (8), and gambling (9,10). The Ontario Child Health Study found that children with emotional disorder were more likely to come from families that were receiving welfare and (or) were exposed to such parental social problem behaviour as divorce, unemployment, and crime (11). Results from the ECA studies in the US point to a comorbidity of most DSM-III disorders with divorce, alcoholism, drug abuse, and unemployment (12), and Robins and Kulbok found that major depression was closely associated with suicide (13). Earlier, Leighton and others, in the Stirling County Study conducted in Nova Scotia, found that social disintegration in communities was associated with serious mental disorder (14). This is important because it suggests a role for ecologic factors that might operate in addition to, or in interaction with, individual characteristics. An important observation is that the 1-year prevalence for any particular problem varies considerably across provinces. Table 1 shows the ratios of the highest to the lowest provincial rates for the 8 problems of the Canadian SPI for 1971 and 1981 (the years used in the development of the index) (1). These differences are large enough to be expressed in multiples, rather than in fractional increments. The lowest ratio is 2.1 for sexual assault, ranging to a high of 18.8 for robbery, both in 1981 (mean ratio 6.5). Since social problems show high levels of association with diagnosable psychiatric disorders (across individuals), the question that asserts itself is whether these 2 variable classes are associated across geographic regions as well. On the heels of this notion is the question of whether psychiatric disorders show variations across geographic areas that are as dramatic Can J Psychiatry, Vol 50, No 10, September 2005

3 Variations in the Prevalence of Psychiatric Disorders and Social Problems Across Canadian Provinces as those found for social problems. In our earlier work, we posited a model derived from the working hypothesis that the expression of social problem behaviour was due to an interaction between individual factors (specifically, mental disorder) and the social environment (1). It was assumed that the proportion exhibiting a mental illness would not have varied across provinces as dramatically as social problem prevalences, thus leaving the social environment as a likely explanation for the interprovincial differences in social problem behaviour levels. Until the appearance of the CCHS 1.2, these questions could not be addressed in the Canadian context because of the absence of comparative diagnostic data across provinces and territories (territorial data are still unavailable). The purpose of this study was to determine the nature of the covariation and distribution of social problem behaviour and mental illness on the basis of a population sample across provinces, whose governments are responsible for most health care and social problem services. This was accomplished by deriving provincial mental illness rates from the CCHS 1.2 database and comparing these with existing SPI values. The specific hypotheses were that 1) the SPI would be correlated with psychiatric prevalences across provinces, and 2) the range of prevalences for mental illnesses, across provinces, would be less than that for social problems. Methods An ecologic-correlational design was used, with the unit of measurement at the provincial level. The CCHS 1.2 Of direct relevance to the present proposal is that the CCHS 1.2 provides comprehensive data for a selection of major mental illnesses, addictions, and social problems. Details on the methodology can be found elsewhere in this issue (15), but it is important to summarize the points that are relevant to the present study. Statistics Canada conducted the CCHS 1.2 in Most interviews were face-to-face, with telephone interviews comprising about 14% of the total. Only persons living in private occupied dwellings in the 10 provinces were sampled. Excluded were those living on Indian Reserves and Crown Lands, residents of institutions, full-time members of the Canadian Armed Forces, and residents of some remote areas. The sample size for the 10 provinces was , with a combined response rate of 77% (16). Measures The measures selected for use included 5 psychiatric diagnoses: major depressive disorder, mania, panic disorder, social anxiety (social phobia), and agoraphobia. SPI values were calculated for the year 2002 with the methodology that was applied to the years (1). Each social problem was handled separately, which allowed the conversion of provincial rates to standard scores. Social problem scores were then combined with coefficients derived from a principal components analysis (to extract only common variance). Finally, these were converted to an index score for each province that was based on 1956 values, which were arbitrarily set to have a mean score of 100 with an SD of 15. From the CCHS 1.2 database, the month prevalence of each diagnosis was calculated for each province. Statistical Analysis The SPI was designed to provide a reflection of the state of the population in question. Thus cross-province adjustments were not made for such factors as age and sex (which can, nonetheless, be studied as explanatory variables). However, the CCHS 1.2 samples did not necessarily match provincial distributions on variables such as age and sex at the provincial level. In response to this, CCHS 1.2 data were adjusted to each province s population age and sex distributions. That is, age and sex figures may differ across provinces, but within provinces, the SPI and CCHS 1.2 prevalences were derived from matched distributions. The analysis of these data, then, will involve determining the strength of the association between prevalences of the psychiatric diagnoses and social problem rates across provinces. Results The rising westerly trend of the SPI found in previous years was reproduced in 2002 (see Figure 1). The correlation between the Index and the longitudinal rank of each province was This was also true for some of the diagnoses. Depression and mania both showed westerly correlations of 0.64, but phobia showed a small value (0.38), and panic disorder and agoraphobia showed no such relation (r = 0.14 and 0.0, respectively). The expected positive associations between the SPI and the psychiatric diagnoses did not materialize in Phobia showed the strongest relation (r = 0.43), followed by agoraphobia (but in the wrong direction at r = 0.23), depression ( r = 0.21), panic disorder (r = 0.07), and mania (r = 0.06). This appears to bring into question the above-mentioned prediction that the 2 types of measures would be correlated. However, this does not tell the whole story. It turns out that the diagnoses have interesting relations with SPI values from previous years, suggesting that some of the supposed effects were delayed. The associations from 1981 to 2002 (expressed as r 2 values) are depicted in Figure 2. Both major depression and mania showed quite high associations with social problem rates 21 years prior to their diagnosis, but these gradually Can J Psychiatry, Vol 50, No 10, September

4 The Canadian Journal of Psychiatry CAPE Special Issue Figure 1 Cross-province trends for depression, phobia, mania, and the SPI (2002) 8% 160 7% 150 6% Month Prevalence 5% 4% 3% Social Problem Index Depression Phobia Mania SPI (Axis2) 2% 100 1% 90 0% BC AB SK MB ON QUE NB NS PEI NF 80 Figure 2 The proportion of cross-province variation in the 2002 psychiatric diagnoses accounted for by the SPI, from r Depression Mania Panic Phobia Agoraphobia Can J Psychiatry, Vol 50, No 10, September 2005

5 Variations in the Prevalence of Psychiatric Disorders and Social Problems Across Canadian Provinces Table 2 Ratio of highest to lowest provincial value for each diagnosis and social problem Diagnosis High-to-low ratio Social problem High-to-low ratio t = 0.13 Depression 2.2 Homicide 8.1 Mania 7.9 Attempted murder 6.0 Panic disorder 5.9 Assault 2.8 Phobia 2.1 Sex offence 2.7 Agoraphobia 7.1 Robbery 10.2 Divorce 1.6 Suicide 2.7 Alcoholism 7.6 Mean 5.1 Mean 5.2 taper off to a negligible level during the contemporaneous assessment in Conversely, the 3 anxiety disorders showed some smaller increases, with a slight downturn in the latter years. However, panic disorder and agoraphobia did not play a large part during any period. Table 2 indicates that the mean diagnosis and social problem rate ratios (comparing the lowest province with the highest) do not differ overall. Further, these values are comparable with the social problem ratios found in 1971 and 1981 (shown in Table 1). Thus the data indicate that both social problems and psychiatric diagnoses vary across provinces and that they vary at about the same mean level. Discussion The data presented here confirm that the already established association between social problems and mental illness within individuals also has validity across geographic areas. This is a situation where the results of clinical observations, community surveys, and ecologic studies are similar, dispelling any concerns about an ecologic fallacy. Clearly, social problems and mental disorders show some form of meaningful relation. The twist is that the associations were evident only when there was a time lag between the measurement of the SPI and the psychiatric disorders. Why this is remains to be seen, but it may well reflect the high likelihood that people showing recent evidence of disorder would have experienced its genesis many years earlier. This is certainly an area where further research would be warranted. As noted, the working hypothesis here was that the expression of social problem behaviour is a consequence of an interaction between individual differences in vulnerability (conceptualized as mental disorder) and the social environment (1). It was assumed that mental illness rates would not have varied across provinces as dramatically as the SPI, thus leaving the social environment as a likely explanation for the difference in the range of social problem rates. Since, however, mental illness rates have now been shown to exhibit a variability of about the same magnitude, this working hypothesis has to be questioned. It may be more reasonable to reexamine the alternate hypothesis that mental illness provides the most significant impetus for the production of social problem behaviours. It is also possible that social factors play a larger role in the expression of psychiatric disorders than originally assumed here. This issue has a particularly current implication for suicide research, where several investigators have observed a strong association between the presence of mental disorder and completed suicide (17,18). This has led to a view that the primary mode of suicide prevention should be psychiatric and (or) psychological treatment (19). These findings are, however, somewhat suspect; they are based primarily on information collected after death (from family, friends, and records) and are thus subject to the well-known biases inherent in retrospective data. In any case, the results of the present study coupled with the recent and rapid rise in knowledge about genetic and gestational processes suggest that research directed toward an understanding of the relative influence of societal factors and individual predispositions would be enlightening and beneficial. The interprovincial differences noted here, if taken as differences in need, have implications for the planning and funding of services. From a federal stance, it is clear that a per capita approach to provincial or territorial resource allocation cannot address need in an equitable fashion. From a provincial or territorial view, the data indicate that mental health and social problem matters need to be given a higher priority in some cases. All this still leaves open the question of why both the SPI and some diagnosis rates increase as we move from east to west in Can J Psychiatry, Vol 50, No 10, September

6 The Canadian Journal of Psychiatry CAPE Special Issue Canada and poses the question of whether mental illnesses, like social problems, have risen in prevalence over the past several decades. Acknowledgements The author acknowledges the assistance of Ken Morrison of Alberta Health and Wellness and Ying Liu of the University of Alberta for assistance in locating data for this study. References 1. Thompson AH, Howard A, Jin Y. A social problem index for Canada. Can J Psychiatry 2001;46: Thompson AH, Cui X. Increasing childhood trauma in Canada: findings from the National Population Health Survey, Can J Public Health 2000;91, Thompson AH, Bland RC. Social dysfunction and mental illness in a community sample. Can J Psychiatry 1995;40: Bland RC, Stebelsky G, Orn H, Newman SC. Psychiatric disorders and unemployment in Edmonton. Acta Psychiatr Scand 1988;77(Suppl 338): Dyck RJ, Bland RC, Newman SC, Orn H. Attempted suicide and psychiatric disorders in Edmonton. Acta Psychiatr Scand 1988;77(Suppl 338): Bland RC, Orn H. Psychiatric disorders, spouse abuse, and child abuse. Acta Psychiatr Belgica 1986;86: Helzer JE, Canino GJ, Eng-Kung Y, Bland RC, Lee CK, Hwu HG, and others. Alcoholism North America and Asia: a comparison of population surveys with the DIS. Arch Gen Psychiatry 1990;47: Bland RC, Newman SC, Dyck RJ, Thompson AH. Prevalence of psychiatric disorders and suicide attempts in a prison population. Can J Psychiatry 1990;35: Bland RC, Newman SC, Orn H, Stebelsky G. Epidemiology of pathological gambling in Edmonton. Can J Psychiatry 1993;38: Newman SC, Thompson AH. A population-based study of the association between pathological gambling and attempted suicide. Suicide Life Threat Behav 2003;33(1): Offord D, Boyle M. The Ontario Child Health Study: summary of initial findings. Toronto (ON): Queen s Printer for Ontario; Robins LN, Regier DA. Psychiatric disorders in America. New York: The Free Press; Robins LN, Kulbok PA. Methodological strategies in suicide. In: Mann J, Stanley M, editors. Psychology of suicidal behavior. Annals N Y Acad Sci 1986;487: Leighton DC, Harding JS, Macklin DB, Macmillan AM, Leighton AH. The character of danger: psychiatric symptoms in selected communities. New York: Basic Books; Gravel R, Béland Y. The Canadian Community Health Survey: Mental Health and Well-Being. Can J Psychiatry 2005;50: Statistics Canada. Canadian Community Health Survey, Mental Health and Well-Being, Cycle1.2. Master file documentation. Ottawa (ON): Statistics Canada, Available: _D4_T1_V1_E.pdf. Accessed 2005 Jan Tanney BL. Psychiatric diagnoses and suicidal acts. In: Maris RW, Berman AL, Silverman MM, editors. Comprehensive textbook of suicidology. New York: Guilford; p Hawton K, van Heeringen K, editors. The international handbook of suicide and attempted suicide. Chichester (UK): Wiley; Jamison KR. Night falls fast. New York: Vintage Books; Manuscript received and accepted May Previously presented at the Canadian Asscoiation of Psychiatric Epidemiology; 2004 October 14; Montreal (QC). 1 Suicidologist, Alberta Centre for Injury Control and Research; Associate Professor, Department of Public Health Sciences, Clinical Sciences Building, University of Alberta, Edmonton, Alberta. Address for correspondence: Dr G Thompson, Department of Public Health Sciences, Clinical Sciences Building, University of Alberta, Edmonton, AB T6G 2G3 gus.thompson@ualberta.ca Résumé : Les variations de la prévalence des troubles psychiatriques et des problèmes sociaux entre les provinces canadiennes Objectif : Déterminer les taux de prévalence provinciale de 12 mois de troubles psychiatriques choisis et évaluer l association entre ceux-ci et l indice des problèmes sociaux (IPS) canadien. Méthode : Les données psychiatriques de la dépression, de la manie, du trouble panique, de la phobie sociale et de l agoraphobie ont été dérivées des résultats du Cycle 1.2 de l Enquête sur la santé dans les collectivités canadiennes L IPS canadien a été mis à jour en 2002, et les corrélations ont été calculées entre celui-ci et les 5 valeurs de prévalence diagnostique dans les provinces. Résultats : Les résultats indiquaient que l IPS maintenait sa tendance à la hausse d est en ouest au pays, tendance reflétée par la dépression et la manie. Les troubles psychiatriques ne présentaient pas de fortes corrélations avec l IPS en 2002, mais la dépression et la manie affichaient des associations relativement fortes avec les valeurs de l indice des années antérieures. Pour ce qui est des problèmes sociaux individuels, les ratios d élevés à faibles des provinces étaient supérieurs à5enmoyenne, et les résultats étaient essentiellement de la même ampleur pour la gamme des diagnostics psychiatriques particuliers. Conclusions : Les différences de besoin constatées ici suggèrent que l allocation par habitant des fonds pour la santé mentale et les programmes sociaux n est peut-être pas appropriée. Les résultats partagés sur l association entre les troubles mentaux et les comportements de problèmes sociaux entre les provinces provoquent davantage de questions que de réponses de recherche. 642 Can J Psychiatry, Vol 50, No 10, September 2005