Canadian Public Health Association Conference 2008 Annual Conference Public Health in Canada: Reducing Health Inequalities through Evidence and Action Halifax, Nova Scotia June 1-4, 2008 The Prevalence of Depressive Symptoms in Canadians at Midlife Conita Ip, M.A. PhD Student Jian Kang, PhD Candidate University of Calgary

Introduction Depression is a common health problem affecting 121 million people worldwide. By 2020, it is projected that depression would become the second leading cause of global disability and premature death (WHO, 2002).

Prevalence of Major Depressive Episode in Canada 1 in 7 adults (13.4%) identified symptoms that met the criteria for a mood disorder at some point during their lifetime. The lifetime prevalence for depression in adults aged 15 and over was 12.2% while the 12-month prevalence was 4.8% (men: 3.7%, women: 5.9%). (The human face of mental health and mental illness in Canada 2006 using data from the 2002 Mental Health and Well-being Survey (CCHS 1.2))

Suicide Rates in Canada Statistics Canada reported that suicide is one of the leading causes of death for both sexes from adolescence to middle age. In 2003, 3,765 Canadians died due to suicide. Among them, 1,337 were midlife adults aged 45-64, constituting 35.5% of all suicidal deaths. (Centre for Chronic Disease Prevention and Control, Public Health Agency of Canada using data from the Mortality File, Statistics Canada)

Rationale for the Current Study Midlife is a crisis stage during which people begin to detach from well-ordered life and experience changes in unanticipated ways (Levinson, 1978; Vaillant, 1977) or an opportunity for growth ? It is a period the middle-aged adults negotiate with a wide range of challenges in family, work and individual domains (Bumpass & Aquilino, 1995). Despite the challenges facing midlife adults, the rising mid-aged suicides and the fact that they constitute the largest subpopulation in the country, research effort focusing on midlife psychological wellbeing in Canada is limited. As such, an examination of the factors associated with midlife depression is warranted.

Recent Research on Midlife & Psychological Well-being Personality traits (low instrumentality, anger-in, pessimism and anxiety traits) and life course perspective/life events (becoming widowed, becoming a caregiver, having undergone surgical menopause, stressful life events and poor health status, having HIV infection or AIDS, having personal perception of risk of pandemic infection) are among the mainstream explanations (Bromberger & Matthews, 1996a; 1996b; Dennerstein et al., 2004; Kalichman et al, 2000; Klohnen, Vandewater & Young, 1996; Turner, Killian & Cain, 2004; Woods, Mitchell, 1997; Yu et al., 2005)

Limitations of Recent Research Studies Do not address the complex interplay of the individual differences and their relationship with the socio-structural environment. Almost all of the studies focused on middle-aged women instead of looking at both sexes, thus cannot extend its generalizability to the entire population. Sample bias – sample from higher socio-economic group or lack of ethnic diversity

Theoretical Framework for the Current Study Individual factors and aspects of one’s social environment are key elements related to health status (Keller-Olaman et al, 2004) Population health perspective has become significant in academic and health policy discourse (Hayes & Dunn, 1998). It refers to the health of a population as measured by health status indicators and as influenced by factors, including income and social status, social support network, education and literacy, employment and working condition, social environments, physical environments, personal health practices and coping skills, healthy child development, biology and genetic endowment, gender and culture (Hayes and Dunn, 1998; Health Canada, 2002; Marmot & Wilkinson, 1999). There is a growing body of evidence that social environments are crucially important for a healthy population. However, a systematic review of the social determinants of mental health in middle-aged Canadians is lacking.

Methods Canadian Community Health Survey (CCHS Cycle 2.1) is a cross-sectional survey that collects information on health status, health determinants and health care utilization for the Canadian population aged 12 or older, living in private dwellings. Data was collected between January 2003 and December 2003, for 126 health regions, covering all provinces and territories. In this study, we undertook an analysis of the cohort of 42,006 midlife subjects aged 40 to 59. After deletion of cases with missing values, the total sample for analysis was reduced to 13, month prevalence was estimated using logistic regression analysis.

Measurement Composite International Diagnostic Interview-Short Form (CIDI-SF) is a comprehensive, fully-standardised diagnostic instrument designed tp provide a 12-month prevalence estimates of depressive episodes in general population based on the definitions and criteria of ICD-10 (International Classification of Diseases, version 10) and DSM-III-R (Diagnostic and Statistical Manual of Mental Disorders, 3 rd ed., revised)

Variables Dependent/Outcome Variable: depression Independent Variables: Gender Age Marital Status Education Income Immigrant Status Chronic Health Conditions

Results (1) MDD Prevalence in relation to Demographic Variables VariableCategoryAnnual Prevalence(%) SexMale 7.5 Female 12.3 (Male)(Female) Age Marital StatusMarried Separated/Divorced/ Widowed Single EthnicityBorn in Canada Immigrant

Results (2) MDD Prevalence in relation to Demographic Variables VariableCategoryAnnual Prevalence(%) (Male)(Female) EducationLess than Secondary Secondary or above Annual IncomeLess than $15, $15,000-29, $30,000-49, $50,000 or above Chronic IllnessHas a chronic condition No chronic condition

Discussions Consistent with previous research, those who are women, with less education, less income, chronic illness, and being widowed, separated, divorced and single have higher prevalence of depressive symptoms. Immigrants experience lower prevalence of depressive episodes probably because the pre-entry process has screened out individuals with health problems, as well the cultural differences in expression of emotions.

Recommendations Structural Level – -Creating supportive environment -Reorienting health care delivery models (e.g. customer- oriented, training of GPs in identification of negative emotions) -Reorienting public policy Individual Level – -Enhancing personal capacity on recovery and reintegration into community.

Limitations CCHS 2.1 is a cross-sectional survey, does not reflect the causal relationship between variables. CIDI-SF is a non-clinical diagnostic instrument used by trained lay interviewers, lacks clinical judgement. Lots of missing data in the variables of work stress and social support which are two crucial areas for explaining the prevalence of depression.

Thank You