Grant: Project Grant

Major affective or non-affective disorders (MP) affect 4% of the population. The human and financial costs are enormous. Because the exact causes in the brain are not yet exactly known, treatments are palliative, rarely curative. In the G7 nations, millions of children are born to a parent affected by MP. Not only have these youths a 15-fold risk increase to develop MP but they also carry early in life a load of developmental disorders that represent a challenge for paediatricians and child health care practitioners. Research on "clinical-high risk" (CHR) youths aged 17 to 28 have produced many findings in vulnerabilities and interventions, but the CHR stage might be a late phase of risk. Research on earlier phases of risk may be crucial to understand the neurodevelopmental roots of major psychoses. Understanding the developmental trajectory and the early sensitive periods of vulnerability in the life of children-adolescents at risk is of utmost relevance for developing efficient preventive and curative means. Stemming from the applicant's longitudinal research program that followed-up over 30 years a large sample of kindreds densely affected by MP, this study will assess the stages of the childhood "risk syndrome" of MP. This "risk syndrome" is defined by the clustering of risk indicators (such as cognitive impairments, electroretinographic anomalies, childhood psychotic-like experiences) under environmental stressors (e.g. abuse and neglect) that progressively aggregate during sensitive vulnerability windows along the risk trajectory until the CHR phase. Specifically, Maziade and colleagues will investigate the evolution of this clustering of risk indicators in a vulnerable child over time, and its association with a child's progressive functional deterioration. This will provide the basis for defining progressive preclinical stages in the child's risk status to be used in primary care and prevention.