Urban adolescents at greater risk of psychosis, study shows

A new study from King’s College London and Duke University has shown that living in a city could significantly increase young people’s vulnerability to psychotic experiences.

Published in Schizophrenia Bulletin, the study found that British adolescents raised in major cities in England and Wales were over 40 per cent more likely to report psychotic experiences (e.g. hearing voices and feeling extremely paranoid) than their rural counterparts.

The report highlighted that among adolescents who had grown up in the most adverse neighbourhoods and been victim of a violent crime, 62 per cent reported psychotic experiences. This high rate of psychotic experiences was almost three times greater than among adolescents living in more favourable neighbourhoods.

The researchers from King’s interviewed more than 2,000 British 18-year-olds about psychotic experiences since the age of 12. Adolescents were considered to have psychotic experiences if they reported at least one out of thirteen potential experiences including, for example, that they heard voices that others could not, believed they were being spied on, or their food was being poisoned.

Levels of ‘urbanicity’ were assigned to each participant via their postcode, using data from the Office of National Statistics. Neighbourhood social factors, such as trust, support and cooperation between neighbours, and signs of threat like muggings, assaults and vandalism were measured through surveys of over 5,000 immediate neighbours of the participants. Finally, personal victimisation by violent crime was assessed through interviews with the participants themselves.

Among those who lived in the largest, most densely populated cities, 34 per cent subsequently reported psychotic experiences between age 12 and 18, compared to 24 per cent of adolescents in rural settings.

The study authors suggested a number of reasons why living in a city could pose a risk for psychotic experiences, including a heightened biological response to stress, which can in turn disrupt the activity of dopamine in the brain. Excess dopamine is the best biological explanation researchers currently have for psychotic illnesses such as schizophrenia.

Jo Newbury, first author of the study, from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London, said: “Our study suggests that the effects of city life on psychotic experiences are not limited to childhood but continue into late adolescence, which is one of the peak ages at which clinical psychotic disorders are typically diagnosed.”

Dr Helen Fisher, senior author from IoPPN at King’s College London, said: “These findings highlight the importance of early, preventative strategies for reducing psychosis risk and suggests that adolescents living in threatening neighbourhoods within cities should be made a priority. If we intervene early enough, for example by offering psychological therapies and support to help them cope better with stressful experiences, we could reduce young people’s risk for developing psychosis and other mental health problems further down the line.”

Professor Candice Odgers, senior author from Duke University, said: “As increasing numbers of young people around the world are living in cities, there is a growing need to improve our understanding of how both built and social features of urban settings are supporting and challenging young people’s mental health.”