Psychosis is a severe mental health problem whereby sufferers lose some contact with reality. Two main symptoms of psychosis are hallucinations, where people hear or see something that others cannot, and delusions, where a person has strong beliefs that are not shared by others. People with a psychotic disorder are approximately 2-3 times as likely to have had adverse childhood experiences (ACEs) compared to those without this diagnosis. However, the exact mechanisms linking childhood trauma to psychosis and whether certain characteristics can reduce this risk are unknown. The prevalence of psychotic symptoms reduces from childhood into early adulthood, suggesting that most psychotic experiences in young people are short-term. However, less is known about what factors may predict the persistence of these symptoms. Much of the literature investigating the role of ACEs in the onset of psychosis has been based on study designs which only provide weak evidence about causation. For example, much of the literature relies on case-control studies which can only detect associations, rather than causal relationships between ACEs and psychosis, as a third, unaccounted variable may explain the association.

This project will examine:
(1) The trajectories of psychotic experiences from childhood into early adulthood and whether exposure to ACEs predicts the persistence of symptoms;
(2) whether social factors and cannabis use make the relationship between ACEs and psychosis stronger or weaker; and
(3) pathways linking ACEs to psychosis, namely cannabis use, self-esteem and PTSS (posttraumatic stress symptoms).