Grant: Project Grant

Like almost all other human health conditions, mental disorders are partially determined by 'familial' (i.e., shared) characteristics, which means that individuals are at higher risk if they have an affected relative. However, thus far, mental health service systems have failed to effectively account for this familial clustering. One reason for this is that most studies have focussed on establishing so-called 'individual' risk for mental disorders, assuming that this is causal and should be a focus of interventions. However, this is not true if mental disorders are primarily determined by familial characteristics and not individual risk. Recent statistical advances that take advantage of the unique similarity between twins, make it possible to understand whether familial factors or individual risk primarily cause mental disorders. Using health records of twins in Ontario, Canada, this project will observe the sex-specific emergence of mental illness and substance use disorder across key developmental ages and assess the extent to which these disorders are caused by family characteristics or individual risk as adolescents develop into young adulthood. This project will advance our understanding of the root causes of mental disorders in youth and may offer valuable insight into how we can more effectively prevent mental health and addictions burden before it becomes entrenched and chronic.