Five of the ten leading causes of disability in young people are mental illnesses, of which psychotic disorders, such as schizophrenia, are the most severe and disabling. The Health Service Executive recently launched a National Clinical Programme for Early Intervention in Psychosis, which emphasizes the importance of identifying young people at elevated risk of psychosis before illness onset. This approach highlights the possibility of psychosis prevention. Recent research has shown that the principle current approach used to identify young people at elevated risk of psychosis (called an ‘at risk mental state’) only detects a very small minority of psychosis cases. It is clear, therefore, that if we are to realise the potential of psychosis prevention set out in the National Clinical Programme, we need new, higher capacity strategies to identify more young people at risk of psychosis. Longitudinal research has shown that people who develop psychosis have higher rates of many different childhood problems, including emotional, interpersonal, language, cognitive and motor impairments. Importantly, these are all problems that can lead to referral to child and adolescent mental health services (CAMHS). Therefore, although psychosis is uncommon in childhood, risk for future psychosis might be elevated in children who attend CAMHS. This study will use large European healthcare registers to identify the relationship between CAMHS contact and risk for psychosis. The study will (1) identify the proportion of psychosis cases preceded by CAMHS contact, which will tell us the potential for psychosis prevention in CAMHS (2) determine the risk of psychotic disorders among CAMHS attenders, (3) create a clinical risk calculator for quantifying risk of psychosis in patients who attend CAMHS, (4) investigate medications that may help to reduce the risk of psychosis and (5) produce an information resource for young people with, or at risk of, psychosis, co-designed by service users.
