In 2012, Bentall and collaborators in Maastricht published a meta-analysis of the research literature on childhood trauma and psychosis, considering epidemiological, case-control, and prospective studies. This study found that the evidence that childhood trauma confers a risk of adult psychosis is highly consistent, with children who have experienced trauma (sexual abuse, physical abuse, loss of a parent or bullying) being approximately three times more likely to become psychotic than non-traumatised children; there was a dose-response effect (the most severely traumatised children were even more likely to become psychotic) suggesting that the effect is causal. This finding, and other findings suggesting that there are many social risk factors for severe mental illness, has led to Bentall's current interest in public mental health.