The association between multiple chemical sensitivity and mental illness: Evidence from a nationally representative sample of Canadians

OBJECTIVE

The goal of the present study was to investigate the association between multiple chemical sensitivity (MCS) and major depressive disorder (MDD), generalized anxiety disorder (GAD), MDD and GAD comorbidity (MDD+GAD), severe distress, and positive mental wellbeing.

METHODS

This cross-sectional investigation was carried out using the 2012 Canadian Community Health Survey - Mental Health Component. The study population consisted of 21,977 individuals aged 20 and older, from Canada's ten provinces. Odds ratios were computed using multinomial logistic regression to calculate estimates of the association between MCS and mental illness. All analyses were weighted to take into account the complex survey design.

RESULTS

Individuals with MCS had 2.37 (1.55, 3.64) times greater odds of MDD, 3.09 (1.80, 5.30) times greater odds of MDD+GAD, and 2.60 (1.67, 4.07) times greater odds of severe distress. No association between MCS and GAD was observed. A sex difference was observed with males with MCS having lower odds of positive mental wellbeing, whereas no association was observed in females.

CONCLUSIONS

The present study findings supported an association between MCS and mental illness. The causal mechanism supporting this association remains unclear.

Frequency and content analysis of chronic fatigue syndrome in medical text books

Text books are a cornerstone in the training of medical staff and students, and they are an important source of references and reviews for these professionals. The objective of this study was to determine both the quantity and quality of chronic fatigue syndrome (CFS) information included in medical texts. After reviewing 119 medical text books from various medical specialties, we found that 48 (40.3%) of the medical text books included information on CFS. However, among the 129 527 total pages within these medical text books, the CFS content was presented on only 116.3 (0.090%) pages. Other illnesses that are less prevalent, such as multiple sclerosis and Lyme disease, were more frequently represented in medical text books. These findings suggest that the topic ofCFS is underreported in published medical text books.