Grant: Pr. Gr. - PA: Human Development Child and Youth Health - Mid Career Support

Childhood and adolescence are crucial periods for mental health, with 75% of mental illness cases starting before age 18 and 35% between 11-15 years. Mental illness can take many forms. Having one disorder increases the risk of developing others. Psychosis spectrum symptoms (PSS)-similar to those in psychotic disorders but not severe enough for diagnosis- are linked to worse functioning, more severe symptoms, lower cognitive performance, and higher suicide risk. Our Toronto Adolescent and Youth (TAY) Cohort study team found that youth with PSS have significantly poorer clinical profiles than those without. The TAY study uniquely fills a research gap by longitudinally following young people with mental illness, providing insights into who is most at risk for persistent mental health problems. To deepen our understanding, we will use normative brain modelling, which compares an individual's brain structure to general population data. Deviations from this reference, such as centile scores or brain age gaps, offer valuable insights into brain health and its relevance to mental health risks. By integrating brain imaging with clinical, cognitive, and social data from the TAY study, we aim to connect these deviations to specific mental health outcomes. Our 5-year study of youth aged 11-24 receiving mental health care will use brain scans and other data to explore the relationship between PSS and brain development. We will model changes over time to identify patterns that predict long-term outcomes, like persistent PSS. We will also investigate factors like sex, trauma history, and socioeconomic status that may influence these brain development trajectories. Ultimately, our goal is to develop a predictive model to identify youth at the highest risk for severe or persistent mental health problems, leading to earlier interventions that could improve long-term outcomes.