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The prevalence of depression in Canada is believed to be 4% to 6% (1–4). Key risk factors associated with the development of depression include being poor, unemployed, female, and unmarried (1,4). Age, physical disability, and cognitive impairment have also been associated with the development of depressive symptoms (5). Information on the prevalence of depression and related disorders among Aboriginal people living in Canada is practically nonexistent (6–8). It is generally accepted that the depression rate for Aboriginal people is higher than the non-Aboriginal rate, if for no other reason than that a 2- to 6-times higher suicide rate is found among Aboriginal people in Canada, compared with the non-Aboriginal population (9–12). Although published information exists regarding the prevalence of depression among rural residents, it is somewhat contradictory (1,13). In 1996 Parikh and colleagues reported no difference between rural and urban prevalence rates of depression in Ontario (1). A rural–urban comparison of health indicators published by Statistics Canada in 2003 (13) found that people living in northern regions had high rates of depression, those living in rural regions adjacent to metropolitan regions had low rates of depression, and those living in remote rural regions had prevalence rates equivalent to those reported for Canada. Reasons for these geographic discrepancies in depression prevalence rates have yet to be determined. Rural residents are generally known to be less healthy than their urban counterparts. Rural residents have higher rates of chronic disease; they report being ill more frequently; and they are more likely to report poorer health status (13,14–17). Poorer health among rural residents has in turn been attributed to less education (14,18), lower income (14,19), and a greater proportion of First Nations people in this population (9,20,21). Prescription use of antidepressants is a health indicator that health care administrators monitor when they wish to assess whether people living in a community are receiving appropriate services (9). The goals of these administrators include making sure that health services are allocated fairly and that health care resources are effectively used to optimize the health of the population. The prescription use of antidepressant medications presumably reflects the prevalence of depression–anxiety disorders in a population as well as the degree to which these medications have been chosen by physicians as part of the treatment plans. The provincial health officer for British Columbia reported that 12% of status Indian adults over age 25 years received a prescription for antidepressants in 2000. Comparable data for the non- Aboriginal population were not available (9). The main objectives of our study were to determine depression prevalence rates for Aboriginal and non-Aboriginal populations residing in a remote rural community and to determine the degree to which antidepressant medications were chosen by physicians as part of the treatment plans. MethodsBella Coola Valley is a geographically isolated community located in the central coast region of British Columbia (Figure 1). According to the 2001 British Columbia census, 2285 people lived in the Bella Coola Valley, and 46% of these people were of Aboriginal descent (22,23). Bella Coola Valley is part of the traditional territory of the Nuxalk Nation, which is a tribe of Salish-speaking Coastal Indians (24–27). The United Church Health Medical Services operates a clinic and a hospital in Bella Coola together in the same site. There are no other primary care health facilities in this valley. Three salaried physicians service both the clinic and the hospital (28,29). The isolation of the community is such that almost everyone who lives in the Bella Coola Valley has either a clinic chart or an emergency department record, which makes it an ideal community in which to study population-based health issues. We carried out this research project in a participatory fashion, following the recommendations outlined in a recently published policy statement entitled A Guide for Health Professionals Working With Aboriginal Peoples (6,30,31). Prior to collecting data, we obtained letters of support from the Nuxalk Band Council, the Bella Coola Transitional Health Authority, and the Central Coast Regional District for a comprehensive study on a broad range of determinants of health for people living in the Bella Coola Valley. There were also community meetings where we explained the types of health projects we were doing and planning to do and answered public questions. We obtained approval to collect and summarize chart data from the research ethics committees located at the University of British Columbia and the University of Northern British Columbia. The results and the manuscript were reviewed and approved for publication by both Nuxalk health professionals and United Church Health Services health professionals. A family physician who has worked in Bella Coola for over 15 years did 2 separate chart reviews. The first chart review was done in August and September 2001 to define an active clinic population, that is, to determine who was still living in the Bella Coola Valley. With the exclusion of clinic charts of people not living within the Bella Coola Valley, 2375 patients made up the October 2001 clinic population list—approximately 104% of the May 2001 census estimate for the Valley. After the Bella Coola Medical Clinic population was defined, the 2375 active clinic charts were reviewed in the spring of 2002 for demographic information (that is, age, sex, and Aboriginal status). People suffering from a depression–anxiety disorder in 2001 were identified, as were those prescribed antidepressant medications in the same year. The indications for prescribing that particular antidepressant medication were also recorded (32–35). Figure 1 Detailed map of Bella Coola Valley 
The antidepressant medications prescribed included tricyclic antidepressants (amitriptyline, clomipramine, desipramine, doxepin, imipramine, nortriptyline, and trimipramine), selective serotonin reuptake inhibitors (fluoxetine, fluvoxamine, paroxetine, sertraline, and citalopram), a reversible monoamine oxidase inhibitor (moclobemide), a norepinephrine and dopamine modulator (bupropion), serotonin antagonist and reuptake inhibitors (nefazodone and trazodone), and a serotonin norepinephrine reuptake inhibitor (venlafaxine). Patients presenting to a family physician with affective depressive disorder, situation depression, anxiety disorder, a mixture of debilitating depressive–anxiety symptoms, or bipolar disorder were classified as suffering from a depression–anxiety disorder. Patients seen for relatively minor stress or anxiety symptoms alone were not classified as having a depression–anxiety disorder. Patients designated as having an anxiety disorder had to have a recognizable DSM-IV anxiety disorder diagnosis (for example, panic attack disorder, agoraphobia, obsessive–compulsive disorder, posttraumatic stress disorder, or generalized anxiety disorder). In this study, anxiety disorder does not include patients seen only once or twice who were said to be suffering from a few anxiety symptoms alone (29). In Canada, 3 groups of Aboriginal people are recognized: First Nations (formerly referred to as Indians), Métis, and Inuit (9,12). An estimated 3.6% of the entire British Columbia population is Aboriginal. To determine the Aboriginal status of people living in the Bella Coola Valley, we used information from multiple sources, including Nuxalk Band lists, archived birth and death vital statistics, and a comprehensive genealogy of the Nuxalk people constructed in the 1990s. Some Aboriginal people living in the Bella Coola Valley were not Nuxalk people. We identified these individuals from a review of their charts, from their responses to a survey question asking about Aboriginal status, or by asking directly whether they had Aboriginal ancestry. According to the Bella Coola Medical Clinic population data, approximately 47% of the residents of the Bella Coola Valley were of Aboriginal descent, almost exactly the same percentage reported by the May 2001 census (46%). We entered chart-derived information into an electronic spreadsheet from which results were summarized, graphs created, and the data sent to statisticians and other researchers for further analyses (36). We analyzed the data using the Statistical Package for Social Sciences (SPSS) for Windows (37). The main outcome measure was the percentage of the patient population who were given a prescription for the specified classes of drugs in 2001. We conducted Pearson chi-square (Asymp Sig [2-sided]) and logistic regression analyses on the data to identify differences between male and female patients, between Aboriginal and non-Aboriginal people, and between increasing ages (38). ResultsWe identified 177 people living in the Bella Coola Valley as suffering from a depression–anxiety disorder in 2001. Of these, 110 (62%) clearly had a major affective depressive disorder; 11 (6%) had situational depression; 21 (12%) had an anxiety disorder; 32 (18%) had a mixture of debilitating depressive–anxiety symptoms; and 3 (2%) had bipolar disorder. Of the 177 people with a depression–anxiety disorder, 164 were over age 18 years, and antidepressants were prescribed for 136 of them. One-year prevalence rates are summarized in Tables 1 and 2 for the total Bella Coola Valley clinic population and for the adult (over age 18 years) clinic population.
With respect to antidepressant medications, 229 different antidepressant prescriptions were prescribed for 179 people (Table 3) in 2001. The greater number of prescriptions reflects the fact that some people received more than one kind of antidepressant during 2001.
Of the 179 people who were prescribed antidepressants, 136 were suffering from a depression–anxiety disorder. These 136 patients with a depression–anxiety disorder received prescriptions for 181 different antidepressants in 2001. Antidepressant medications were prescribed for chronic pain (n = 31 patients) and insomnia (n = 12 patients) in patients not suffering from a depression–anxiety disorder. Amitriptyline (n = 8) and trazodone (n = 4) were the antidepressants used to treat insomnia. Tricyclics and trazodone (n = 2) were used for treating chronic pain, with amitriptyline (n = 26) being the most commonly prescribed antidepressant for this indication. The general pattern of antidepressant medication use among Aboriginal and non-Aboriginal people living in the Bella Coola Valley was as follows (Figure 2):
Pearson chi-square and logistic regression statistical analyses of the antidepressant prescription data revealed significant differences between male and female patients (P < 0.001) and with increasing age (P < 0.001); however, no significant differences appeared between Aboriginal and non-Aboriginal people (P = 0.942). DiscussionThe 1-year (2001) prevalence rate of depression–anxiety disorders for the Bella Coola Valley population was 7.5%. Excluding patients with obvious anxiety disorder and those with bipolar disorder results in a depression prevalence rate of about 6.4%, which is a little higher than previously reported Canadian prevalence rates of depression (1–4). Approximately 77% of the people suffering from depression–anxiety disorders were prescribed antidepressants. Untreated patients included those who had less severe disease, those who refused to take antidepressant medications, those who received formal cognitive psychotherapy, and those who received less formal psychotherapy. Unfortunately, we did not quantify any of these groupings. Interestingly, the number of people with depression–anxiety disorders who were not prescribed an antidepressant was almost identical to the number of people who were prescribed antidepressants for indications other than depression–anxiety, namely, chronic pain and insomnia. Tricyclics accounted for 29% (66/229) of the total antidepressant prescriptions, and SSRIs accounted for 51% (117/229) of the total, which is consistent with Canada-wide prescribing patterns for anti- depressants (4,39). According to our data for Bella Coola Valley, 11% of the Aboriginal population and 10.5% of the non-Aboriginal population over age 25 years received a prescription for antidepressants in 2001. The peak use of antidepressants occurred among Aboriginal women aged 45 to 64 years, with a prescription rate of 17.8% (Figure 2); this rate is roughly the same as that reported for status Indian women of British Columbia (9). Our finding that rates in male and female patients were lowest in the youngest and oldest age groups has been reported by others (4), as has our finding that women had higher rates of depression (1,40). As previously mentioned, the provincial health officer for British Columbia reported that 12% of status Indian adults over age 25 years received a prescription for antidepressants in 2000 (9). Health care planners and policy makers such as the provincial health officer should be aware of the limitations of using antidepressant prescription rates as a health indicator: not all patients with depression–anxiety disorders are being prescribed antidepressants, and not everyone prescribed an antidepressant has a depression–anxiety disorder. Our data were subject to the limitations inherent in collecting medical chart information—especially, incomplete information and a lack of standardized diagnostic criteria. It was difficult to make precise DSM-IV diagnoses on the basis of the retrospective chart data provided. Some physicians wrote very short notes with little elaboration of the rationale behind the diagnosis of depression, whereas others diagnosed depression from Beck Depression Inventory scores. No one referred to DSM-IV criteria when making the diagnosis of depression, suggesting that this system does not adequately meet the needs of the primary care physicians working in this remote rural community. Last, it is possible that some Bella Coola Valley residents were suffering from depression–anxiety and were never seen by a family physician in 2001. A recent review of family physician visits to the Bella Coola Medical Clinic in 2001 revealed that 26% of the population did not see a family physician at all that year and that 15% of the population accounted for 52% of all visits (Thommasen and colleagues, unpublished). ConclusionThe depression prevalence rate for the Bella Coola Valley population was 6.4%. The rates were similar for the Aboriginal and non-Aboriginal populations. Antidepressant medications were commonly prescribed to both Aboriginal and non-Aboriginal people. When using antidepressant medication prescriptions as a community health indicator, health care administrators should be aware that antidepressant medications are commonly prescribed for conditions other than depression–anxiety disorder. AcknowledgementsWe acknowledge Bill Tallio, Director of the Nuxalk Wellness Program, and Dr R McIlwain, Director of the United Church Health Services, for their support of this project. Funding and SupportDr Thommasen received financial support for this project from the Community-Based Clinician-Investigator Program. References1. Parikh SV, Wasylenki D, Goering P, Wong J. Mood disorders: rural/urban differences in prevalence, health care utilization, and disability in Ontario. J Affect Disord 1996;38:57–65. 2. Bland RC, Newman SC, Orn H. Period prevalence of psychiatric disorders in Edmonton. Acta Psychiatr Scand 1988;77(Suppl 338):33–42. 3. Beaudet MP. Depression. Health Reports 1996;7(4):11–24. 4. Hemels MEH, Koren G, Einarson TR. Increased use of antidepressants in Canada: 1981–2000. Ann Pharmacother 2002;36:1375–9. 5. Blazer D, Burchett B, Service C, George LK. The association of age and depression among the elderly: an epidemiologic exploration. J Gerontol 1991;46(4):M210–M215. 6. Smylie J, Aboriginal Health Issues Committee. A guide for health professionals working with Aboriginal peoples: health issues affecting Aboriginal peoples. J SOGC 2001;100:54–68. Available: http://sogc.medical.org/sogcnet/ sogc_docs/common/guide/pdfs/ps100_2.pdf. Accessed 2005 Mar 9. 7. Young TK. The health of Native Americans: towards a biocultural epidemiology. New York: Oxford University Press; 1994. 8. Newbery PJ. Family practice perspectives on psychiatric care in the Northwest. Can Fam Physician 1988;34:1597–9. 9. British Columbia Provincial Health Officer. A report on the health of British Columbians: Provincial Health Officer’s annual report 2001. Feature report: the health and well-being of Aboriginal people in British Columbia. Victoria (BC): BC Ministry of Health and Ministry Responsible for Seniors; 2002. 10. MacMillan HL, MacMillan AB, Offord DR, Dingle JL. Aboriginal health. CMAJ 1996;155:1569–78. 11. Malchy B, Enns MW, Young TK, Cox BJ. Suicide among Manitoba’s Aboriginal people, 1988 to 1994. CMAJ 1997;156:1133–8. 12. Canadian Institute for Health Information. Aboriginal peoples’ health. In: Improving the health of Canadians. Canadian Institute for Health Information; 2004. Available: http://secure.cihi.ca/cihiweb/dispPage.jsp?cw_page= AR_322_E. Accessed 2004 March 1. 13. Mitura V, Bollman RD. The health of rural Canadians: a rural-urban comparison of health indicators. Rural and Small Town Canada Analysis Bulletin 2003;4(6):1–23. (Statistics Canada cat no 21-006-XIE.) 14. British Columbia Provincial Health Officer. A report on the health of British Columbians: Provincial Health Officer’s annual report 1996. Victoria (BC): BC Ministry of Health and Ministry Responsible for Seniors; 1997. 15. Thiede-Call K, Casey M, Radcliff T. Rural beneficiaries with chronic conditions: does prevalence pose a risk to medicare managed care? Man Care Q 2000;8(3):48–57. 16. Rohrer J, El-Urdaneta M, Vaughn T, Merchant JA. Physician visits in a farming-dependent county. J Rural Health 1998;14:338–45. 17. Yesalis CE, Lemke JH, Wallace RB, Kahout FJ, Morris MC. Health status of the rural elderly according to farm work history: the Iowa 65+ rural health study. Arch Environ Health 1985;40:245–53. 18. Nemet GF, Bailey AJ. Distance and health care utilization among the rural elderly. Soc Sci Med 2000;50:1197–208. 19. Wood E, Sallar A, Schechter M, Hogg R. Universal health care? Poor men more likely to die from “avoidable” causes in British Columbia. The Evidence Speaks Monograph Series, (Monograph Number 1). Available: www.cheos.ubc.ca/publications.html. Accessed 2005 March 10. 20. Gobrial M, Mekael H, Anderson N, Ayers D, Thommasen HV. Diabetic blood sugar control: an urban/rural comparison. B C Med J 2002;44:537–43. 21. McGrail K, Schaub P. British Columbia health atlas. Vancouver (BC): Centre for Health Services and Policy Research, University of British Columbia; 2002. 22. British Columbia Vital Statistics Agency. P.E.O.P.L.E. 27. BC stats.Victoria (BC): BC Ministry of Management Services; 2002. 23. British Columbia Vital Statistics Agency. 2001 British Columbia census. Victoria (BC): Government of British Columbia; 2003. 24. Kennedy DID, Bouchard RT. Bella Coola Indians. In: Suttles W, editor. Handbook of North American Indians. Washington (DC): Smithsonian Institute; 1990. p 323–39. 25. McIlwraith TF. The Bella Coola Indians. Volumes 1 and 2. Toronto: University of Toronto Press; 1992. 26. Thommasen HV. Prehistoric medicine on BC’s central coast. B C Med J 1999;41:343–6. 27. Acheson S. Culture, contact, demography and health among the Aboriginal peoples of British Columbia. In: Stephenson PH, Elliott SJ, Foster LT, Harris J, editors. A persistent spirit: towards understanding Aboriginal health in British Columbia. Canadian Western Geographical Series, Vol 31. Victoria: Western Geographical Press; 1995. p 1–42. 28. Bella Coola General Hospital. Welcome to the Bella Coola General Hospital. Available: http://bellacoola_hospital.tripod.com/. Accessed 2002 Aug 12. 29. Thommasen HV, Newbery P, Watt WD. Medical history of central coast of British Columbia. B C Med J 1999;41:464–70. 30. Macaulay AC, Gibson N, Freeman W, Commanda L, McCabe M, Robbins C, and others. Participatory research maximizes community and lay involvement. BMJ 1999;319:774–8. 31. Cave AJ, Ramsden VR. Hypothesis: the research page. Participatory action research. Can Fam Physician 2002;48:1671–2. 32. American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 4th ed. Washington (DC): American Psychiatric Association; 1994. 33. Reesal RT, Ewing H. The art of managing depression in primary care. Can J CME. 2001;13:209–20. 34. Remick RA. Diagnosis and management of depression in primary care: a clinical update and review. CMAJ 2002;167:1253–60. 35. Hutchison R. Full remission: more likely with newer antidepressant drugs. Patient Care Canada 2002;13:25–33. 36. Harvey G. EXCEL for dummies. 2nd ed. Foster City (CA): IDG Books; 1994. 37. SPSS Inc. Statistical package for the social sciences. Version 10 Chicago (IL): SPSS Inc; 1999. 38. Snedecor GW, Cochran WG. Statistical methods. 7th ed. Ames (IA): Iowa State University Press; 1980. 39. Las Cuevas CD, Sanz EJ, La Fuente JAD. Variations in antidepressant prescribing practice: clinical need or market influences? Pharmacoepidemiol Drug Saf 2002;11:515–22. 40. Angst J, Gamma A, Gastpar M, Lepine JP, Mendlewicz J, Tylee A. Gender differences in depression: epidemiological findings from the European DEPRES I and II studies. Eur Arch Psychiatry Clin Neurosci 2002;252:201–9. Author(s)Manuscript received March 2004, revised, and accepted July 2004. 1. Rural Family Physician, Prince George, British Columbia; Associate Clinical Professor, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia. 2. MSc Student, University of Northern British Columbia, Prince George, British Columbia. 3. Research Assistant, University of Northern British Columbia, Prince George, British Columbia. 4. Statistical Consultant, University of Northern British Columbia, Prince George, British Columbia. Address for correspondence: Dr HV Thommasen, 4202 Davie Avenue, Prince George, BC V2M 4G7 e-mail: thommash@unbc.ca
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