March 27, 2019

expert reaction to urban living, air pollution and psychotic experiences in adolescents

Research published in JAMA Psychiatry demonstrates that air pollution exposure was associated with increased odds of adolescent psychotic experiences.

Dr Daniel Maughan, Associate Registrar for Sustainability at the Royal College of Psychiatrists, said:

“This new research builds on increasing evidence of a likely link between air pollution and mental health issues.

 “While the paper has not proved air pollution causes psychosis, the findings are concerning as they suggest that increased psychosis rates in urban areas are potentially linked to air pollution.

 “We need a radical approach to air pollution as it is very likely damaging the mental health of young and older people alike.”

Prof Andreas Meyer-Lindenberg, Director, Central Institute of Mental Health, Mannheim, University of Heidelberg, said:

“It has long been known that the risk for psychotic experiences is higher in people born and brought up in cities but which aspects of city life are to blame is still unclear. In this paper, the authors find that people exposed to high levels of air pollutions in adolescence were more likely to have psychotic experience, which points to a role of air quality in city risk. While this is a careful study of a large cohort, it should be borne in mind that researcher did not actually measure, but modelled, air quality and also could not know when participants were where. Also, most evidence points to the relevance of early childhood in psychosis risk, a period the study did not cover. While the authors looked at many potential factors that could influence air quality and psychosis risk, such as neighbourhood socioeconomic status, the findings should be replicated in a setting where pollution and location are directly measured before firm conclusions can be drawn.”

Dr Evangelos Vassos, Senior Clinical Research Fellow, King’s College London, said:

“It is very interesting work, implicating air pollution as a risk factor of psychotic experiences in youth. In my view, the evidence appears robust, in particular due to appropriate adjustment for potential confounders. For example, one can obviously think that people growing up in more polluted areas, probably come from lower socioeconomic status, and have higher exposure to substance use or traumatic experiences, both of which are associated with psychotic experience. I noticed with interest that the association of pollution with psychotic experiences remained practically unchanged after adjustment for the above and other family and neighbourhood factors.

“Of course, before making clinical interpretations or public health recommendations, it is important to understand the clinical relevance of the observation, i.e. does the higher level of reported psychotic experiences translate to higher morbidity of psychosis or other mental illnesses?

“The authors imply a causal relationship in their conclusion “global efforts are needed to reduce air pollution levels and protect mental … health of young urban citizens”. These adjustments make a causal relationship between air pollution and psychotic symptoms more likely, but it needs to be noted that this study design cannot prove causality.”

Dr Stefan Reis, Science Area Head, Atmospheric Chemistry and Effects, NERC Centre for Ecology & Hydrology (CEH), said:

“The study makes a valuable contribution to the growing body of evidence that air pollution may affect more than just cardio-vascular and respiratory health. This new study makes a compelling case to investigate a range of mental health outcomes of air pollution exposure. Other variables worth studying could include academic attainment in early life stages and cognitive decline in old age due to early-life exposure to air pollution.

“The OECD (Organisation for Economic Co-operation and Development) established costs of ill mental health at £94 billion a year¹, compared to somewhere between £8bn and £20bn² estimated by the Environment Audit Committee for other causes in 2018. It’s important that we further our understanding of if and how air pollution is related to mental health outcomes which could in future have implications for air quality policies. Findings from future work may well push the ratio between benefits due to avoided health costs versus costs of air pollution control further up and highlight the overall societal benefits of air quality policies.”

Dr Sophie Dix, Director of Research at MQ: Transforming Mental Health, says:

“This study adds important new insight to the discussion on the links between mental health and urban living. The relationship between living in a city and increased mental illness has been something that has been explored for a long time, with many factors considered responsible. This study is significant because it provides a starting point with a possible link between pollution and psychosis, giving future research a platform to build upon. Ruling risk factors in, or out, is helpful in determining how we can best address the issue.

“There is more work that needs to be done with this study. There is no evidence that pollution necessarily causes psychosis or whether this is one of many factors or acting in isolation. There is a bigger picture here, but that does not diminish the importance of these findings and the potential that comes from this.”

‘Association of Air Pollution Exposure with Psychotic Experiences During Adolescence’ by Joanne Newbury et al. was published in JAMA Psychiatry at 15:00 UK time on Wednesday 27th March.

Declared interests

Prof Andreas Meyer-Lindenberg: No COIs.

Dr Evangelos Vassos: Apart from working at the same department as the main authors of the study, I have no other conflicts of interests to report.

Dr Stefan Reis: I declare no conflict of interest or involvement in the study.

Dr Sophie Dix: MQ funds Helen Fisher’s fellowship, although we did not fund this specific piece of work.

None others received.