Chapters in the Epidemiology of child and adolescent mental health: risk factors, prevention, treatment and outcomes
Mental illnesses are a substantial burden in Canada and worldwide. Early life conditions and experiences make individuals more susceptible to developing diseases. The primary goal of this thesis is to understand mental health issues in children and adolescents and to provide a basis for prevention planning and policy. The four core studies in this thesis utilize a variety of epidemiological methods and data sources. The first study, a systematic review and meta-analysis of longitudinal studies, found that early childhood maltreatment is a strong risk factor for the latter onset of depression and anxiety disorders. Proportion attributable fractions (PAFs) indicated a very large reduction in depression and anxiety could result from reducing childhood maltreatment. The second study explored epigenetic changes (DNA methylation) linked to depression. This systematic review found inconsistent results for candidate genes (e.g. BDNF, SLC6A4, NR3C1, OXTR, and others) and genome-wide studies. There was high heterogeneity in terms of experimental and statistical methodologies among the studies. Future studies should apply standardized experimental and laboratory methodologies and adopt longitudinal designs to trace changes overtime. The third study using clinical administrative data examined whether current child and adolescent mental health services effectively improved clients’ psychosocial functioning. Treatment was found to be effective though the initial severity of the problem affected outcomes. While shortening the length of treatment might improve resource use efficiency, it would be detrimental to some clients. Personalized treatment is required to meet clients’ specific needs. Finally, the potential iatrogenic effects (Bipolar Disorder (BPAD)) of pharmacological treatment (stimulant) of children and adolescents for ADHD is examined using a cohort study design and provincial administrative data. After adjusting for psychiatric comorbidity, it was found that stimulant use by itself does not lead to the development of BPAD, but rather the severity of the initial disease and comorbidity are predictors of future BPAD. The clear message of this research is that early reduction in risk factor exposure in utero and in childhood and adolescence and the early treatment of mental health problems has a very positive effect in reducing the onset and further development of psychiatric diseases and mental health problems.
DegreeDoctor of Philosophy (Ph.D.)
DepartmentSchool of Public Health
CommitteeSzafron, Michael; D'Arcy, Carl; Farag, Marwa; Meng, Xiangfei; Dyck, Erika
Copyright DateJuly 2018