Studies on aging and mental health in Canada
Date
2023-09-27
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0000-0002-4335-2618
Type
Thesis
Degree Level
Doctoral
Abstract
ABSTRACT
Mental diseases among older adults are believed to contribute significantly to the disease burden in Canada and globally. Given the considerable increase in aging populations and the change in population compositions over the past decades, both trends and determinants for mental health status among older adults deserve to be studied further. To design effective public health intervention programs and policies, it is required therefore to establish the evidence that could serve as a foundation for interventions. The primary goal of this thesis is to get a deeper understanding of the risk factors, mediators, and trends in mental disorders among older adults in Canada using a wide range of population-based data sources and a variety of epidemiological and statistical approaches. The guiding theoretical framework is a transdisciplinary biopsychosocial model of mental illness which examines biological, psychological, and socio-environmental factors in the development of mental illness looking at these factors in isolation and at their interconnectedness. In this thesis, we look at socio-demographic and psychological factors. Some of the social and psychological factors in mental illness are potentially changeable and thus targets for intervention and prevention.
This thesis consists of seven chapters. The first introductory chapter describes the changes that have occurred in demographic and socioeconomic characteristics and the mental health of Canadian older adults in the past decades. The second chapter describes the study designs, data sources, and statistical analyses used in the following substantive chapters.
In the first substantive study (Chapter 3), we examined the changes in a variety of mental health indicators of older Canadians from 1978 to 2018 using a large set of repeated national cross-sectional surveys. The results of this study revealed that there was a slight decrease in the prevalence of psychological distress and a weak sense of belonging over the past 4 decades among older Canadians. Other mental health indicators, including frequency of consulted mental health professionals, self-reported diagnosed mood disorders, anti-depressant medication use, self-perceived poor mental health, and life dissatisfaction, all displayed significant increases over the past forty years. There seems to be a willingness to acknowledge having mental health problems. Gender differences were evident.
There are a variety of behaviors that have been associated with an increased prevalence of mental illness. Chapter 4, examines whether the relationship between the selected health risk behaviors (physical inactivity, alcohol consumption, and smoking) and their association with depression among Canadians 65+ born in eight cohorts between 1910-1914 to 1945-1949 have changed. We used pooled data drawn from 11 nationally representative health surveys conducted by Statistics Canada between 1994 and 2014. A Cochran-Armitage trend test for categorical outcomes and a log-binomial modeling for binary outcomes were used to estimate the risk ratios across cohorts. We found that physical inactivity and smoking were consistently associated with a significantly increased risk of depression among Canadian residents 65+, with smoking becoming more firmly connected to depression risk in more recent birth cohorts. In contrast, moderate alcohol use was associated with a decreased risk of depression, but that protective effect diminished over time and ceased in the most recent birth cohorts.
The third study (Chapter 5) analyzed the contributions of chronological aging, specific temporal (time) periods, and birth cohort effects on the trends in the major depressive episode (MDE) prevalence among Canadian seniors during the period 1994 to 2018 using data from national health surveys. Our findings showed the presence of strong chronological age and cohort effects and weaker period effects on the prevalence of late-life depression in Canadian seniors. In addition, we found that females 65+ were consistently more likely to be depressed than males 65+ and age exerts a greater effect on females’ probability of developing MDE than males. Our moderation analysis also indicated that lower levels of education significantly contributed to the higher rates of depression among cohorts born earlier in the 20th century.
Chapter 6, tests the associations and interactions between two protective factors and a negative risk factor on feelings of positive mental health and psychological distress among older Canadians. Using data from a large nationally cross-sectional mental health survey, our fourth substantive study (Chapter 6) investigated the complex mediating role of physical activities and social support both separately and combined in influencing the relationships between chronic disease and mental health among older Canadian adults. Our detailed analysis indicated that both physical activity and social support are significant partial mediators between chronic diseases and psychological distress as well as chronic diseases and positive mental health.
A final chapter, Chapter 7, presents the conclusions derived from this research as well as comments on practical implications and directions for future research.
Description
Keywords
Aging, mental health, older adults
Citation
Degree
Doctor of Philosophy (Ph.D.)
Department
School of Public Health
Program
Epidemiology