Grant: Project Grant

Biological markers of risk for serious mental illness, particularly psychotic symptoms, in youth are absent. When a young person develops troubling signs, care providers have no objective criteria with which to diagnose or treat. Patients and parents are left without answers. The proposed study builds on decades of research in blood-based molecular testing and neuroimaging to identify predictive biomarkers in youth seeking care for mental health. Psychotic disorders are a leading cause of disability among youth. Evidence suggests that immune system and stress-related changes measurable in blood may be useful predictors of psychosis symptoms. However, existing work has focused on youth a) already with a first episode of psychosis, or b) meeting strict high risk criteria for psychosis. Unfortunately, these criteria only identify ~5% of individuals who eventually develop a psychotic disorder. As such, an alternative strategy of identifying the majority of youth who develop psychosis - before experiencing a first episode - is needed. We will test a blood panel of 26 stress and inflammatory biomarkers in 900 treatment-seeking youth presenting with mental health concerns to identify stable vs. unstable indicators of psychosis symptoms at baseline and, in a subset of participants, over three years of follow-up. We will also use MRI scans to understand how these biomarkers affect the brain, providing novel insight into the mechanisms linking peripheral blood and the central nervous system. Our work will harness the recently launched Toronto Adolescent and Youth CAMH Cohort Study, a seminal Canadian study of 3000 youth between the ages of 11-24 years, who will be followed over 5 years. This work has the immediate potential to identify relationships of blood biomarkers with psychosis symptoms over time, which may lead to a) robust and generalizable predictors of psychosis symptoms in youth, and b) refined biological and neural targets for interventions and treatments.