28 Mar Urban Youth Exposed to Air Pollution Have Greater Risk of Psychotic Experiences
Posted at 14:05h
in Author Interviews, Environmental Risks, JAMA, Mental Health Research, Pediatrics
MedicalResearch.com Interview with:
Joanne B. Newbury, PhD
ESRC Postdoctoral Fellow
King’s College London
Social, Genetic & Developmental Psychiatry Centre
Institute of Psychiatry, Psychology & Neuroscience
London, United Kingdom
MedicalResearch.com: What is the background for this study?
Response: Urban living is one of the most well-established risk factors for adult psychotic disorders such as schizophrenia. However, less is known about the role of the urban environment in subclinical psychotic experiences in childhood and adolescence, such as hearing voices and extreme paranoia. These early psychotic experiences are a developmental risk factor for adult psychotic disorders and a range of other serious mental health problems such as depression and anxiety.
It is therefore important that we understand what factors might contribute to the development of early psychotic experiences so that we might be able to intervene and prevent their onset and progression.
In a cohort of over 2000 UK-born children (The Environmental Risk Longitudinal Twin Study), we have previously shown that subclinical psychotic experiences are also around twice as common among children and teenagers raised in urban versus rural settings. We have also shown that this appears to be partly explained by social features in urban neighbourhoods such as higher crime levels and lower levels of social cohesion.
However, no studies have examined the potential link between air pollution and psychotic experiences. This is despite air pollution being a major health problem worldwide (particularly in cities), and despite emerging evidence linking air pollution to the brain.

Dr. Mikkola[/caption]
Tomi Mikkola MD
Associate Professor
Helsinki University Hospital
Department of Obstetrics and Gynecology
Helsinki, Finland
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: In Finland we have perhaps the most comprehensive and reliable medical registers in the world. Thus, with my research group I have conducted various large studies evaluating association of postmenopausal hormone therapy use and various major diseases (see e.g. the references in the B;MJ paper). There has been various smaller studies indicating that hormone therapy might be protective for all kinds of dementias, also Alzheimer’s disease.
However, we have quite recently shown that hormone therapy seems to lower the mortality risk of vascular dementia but not Alzheimer’s disease (Mikkola TS et al. J Clin Endocrinol Metab 2017;102:870-7). Now in this upcoming BMJ-paper we report in a very large case-control study (83 688 women with Alzheimer’s disease and same number of control women without the disease) that systemic hormone therapy was associated with a 9-17% increased risk of Alzheimer’s disease.
Furthermore, this risk increase is particularly in women using hormone therapy long, for more than 10 years. This was somewhat surprising finding, but it underlines the fact that mechanisms behind Alzheimer’s disease are likely quite different than in vascular dementia, where the risk factors are similar as in cardiovascular disease. We have also shown how hormone therapy protects against cardiovascular disease, particularly in women who initiate hormone therapy soon after menopause.

Dr. Kuan-Pin Su[/caption]
Kuan-Pin Su, MD, PhD
China Medical University
Taichung, Taiwan
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Delirium, also known as acute confusional state, is a serious disturbance in mental abilities that results in confused thinking and reduced awareness of the environment. Delirium can often be traced to one or more contributing factors, such as a severe or chronic illness, changes in metabolic balance (such as low sodium), medication, infection, surgery, or alcohol or drug intoxication or withdrawal. It’s critically important to identify and treat delirium because some of the contributing factors could be life-threatening. However, there is no sufficient evidence for choice of medication to treat or prevent the symptoms of delirium.
A recent paper, Association of Delirium Response and Safety of Pharmacological Interventions for the Management and Prevention of Delirium A Network Meta-analysis, published in JAMA Psychiatry provides important findings of this missing piece in that important clinical uncertainty. The leading author, Professor Kuan-Pin Su, at the China Medical University in Taichung, Taiwan, concludes the main finding about treatment/prevention of delirium: “In this report, we found that the combination of haloperidol and lorazepam demonstrated the best option for treatment of delirium, while ramelteon for prevention against delirium.


Dr. Vallerand[/caption]
Isabelle Vallerand, PhD
Epidemiologist, MD Student
Department of Community Health Sciences
Cumming School of Medicine
University of Calgary
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: It is well known that patients with alopecia areata, a form of autoimmune hair loss, are at a higher risk of suffering from depression than the general population. But in practice, we often hear patients tell us that they believe their hair loss developed as a result of stress or problems with mental health – certainly the phrase “so stressed your hair is falling out” is something most people have heard of. Despite this, there has actually been very little research investigating the role that mental health may have on development of alopecia areata.
Interestingly, depression has recently been associated with increased systemic inflammatory markers, so there is biologic plausibility that depression could increase the risk of alopecia areata. Our group was interested in addressing this question, and used a large population-level health records database with up to 26 years of follow-up to study it. We ultimately found that not only does depression increase one’s risk of alopecia areata, but that it increases their risk by nearly 90% compared to people who have never had depression. We also found that using antidepressants can significantly decrease the risk of developing alopecia areata in patients with depression. So there appears to be an important link between mental health and development of hair loss from alopecia areata.