Teenagers who live in large cities could be at greater risk of having psychotic experiences, according to research examining the impact of urban life on mental health.
The finding ties in with previous studies and suggests that early interventions for young people in deprived urban neighbourhoods could be valuable.
“There is a growing interest in early interventions for psychosis and although it is important to highlight that the vast majority of these adolescents won’t go on to develop a psychotic disorder, early psychotic experiences are shown to be associated with a heightened risk for other mental health problems as well,” said Joanne Newbury, co-author of the research from King’s College London.
The research was published in Schizophrenia Bulletin by teams in the UK and US.
It drew on the Environmental Risk Longitudinal Twin Study, in which 2,063 18-year-olds in England and Wales were asked whether they had had any psychotic experiences since the age of 12, including delusions, hallucinations or concerns that their food had been poisoned. Just over 30% of the teens reported at least one psychotic experience over the period.
Once factors including family psychiatric history, socioeconomic status and alcohol or cannabis dependence were taken into account, the odds were 43% higher for adolescents living in very urban settings – such as cities like London or Birmingham – than for rural teens.
Further analysis revealed the effect was at least in partly down to low levels of social cohesion, meaning poor relationships between neighbours, and high levels of neighbourhood disorder.
“We found that these factors explained around half of the association, or the effect of urbanicity on psychotic experiences,” said Newbury.
Being a victim of violence made the odds of an adolescent having psychotic experiences three times greater, while teens living in neighbourhoods with high disorder and low social cohesion were more likely to have been victimised.
The rate of psychotic experiences was three times higher among that group, at 62%, than among those who lived in more favourable neighbourhoods and had not been the victim of violent crimes, for whom the rate was 21%.
However, the authors noted that the research does not prove that particular environmental settings are the cause of the higher rates of teen psychotic experiences. They pointed out that it was possible that those at greater risk of psychosis might move into urban environments.
But they said the study suggested that early interventions for the mental health of those living in urban neighbourhoods and deprived areas could prove valuable.
James Kirkbride, a psychiatric epidemiologist from University College London, said:
“We already know that people who are born, brought up in and live in cities have a higher chance of experiencing a psychotic disorder in their life. This new study shows that this extends to psychotic symptoms in adolescence as well.”
Kirkbride added that it was not yet clear what might be behind the link, although he noted that the latest study suggests that living in disadvantaged neighbourhoods or settings with high crime rates could be a factor.
“Above all, this data shows that our most disadvantaged communities face a disproportionate burden of psychosis-related health inequalities in the UK, and require the provision of appropriate mental health services to tackle this issue,” he said.
