Psychosis incidence highly variable internationally

Rates of psychosis can be close to eight times higher in some regions compared to others, finds a new study led by researchers at King's College London, UCL and the University of Cambridge. The study, published today in JAMA Psychiatry , was the biggest international comparison of incidence of psychotic disorders, and the first major study of its kind in more than 25 years. 'It's well-established that psychotic disorders, such as schizophrenia, are highly heritable, but genetics don't tell the whole story. Our findings suggest that environmental factors can also play a big role,' said the study's lead author, Dr James Kirkbride from UCL. 'We need more in-depth research to understand why people in some areas may be at greater risk of developing a psychotic disorder, which could help us understand the roots of the condition and guide health care planning,' he said. The authors estimated the incidence of psychotic disorders across 17 areas in six countries - the UK, France, Italy, the Netherlands, Spain and Brazil - using comparable methodology. Their data was drawn from people aged 18-64 who contacted mental health services after a suspected first psychotic episode, which included 2,774 incident cases in total.