Study Finds Increased Risk of Psychiatric Disorders Linked to Asthma, Allergies

Allergic diseases such as asthma were associated with a 1.66-fold increased hazard of psychiatric disorders in Taiwan, according to a large study published in Frontiers in Psychiatry. The researchers said it is the first study to find a connection between common allergic diseases and the overall risk of developing psychiatric disorders.

Almost 11% of patients with common allergic diseases developed a psychiatric disorder within a 15-year period, compared to only 6.7% of those without.

The data was drawn from the Taiwan National Health Insurance Program. A total of 186,588 enrolled patients, with 46,647 study subjects who had suffered from allergic diseases, and 139,941 controls matched for sex and age, from the Longitudinal Health Insurance Dataset of 2000-2015, were selected from a sub-dataset of the National Health Insurance Research Database.

Results showed that 5038, or 10.8%, developed psychiatric disorders, a statistically significant difference from the control group&shy;—9376, or 6.7%. A risk model analysis showed that the adjusted hazards ratio was 1.659 (95% CI, 1.602-1.717; P <.001).

Having atopic dermatitis alone, or allergic rhinitis plus atopic dermatitis, was associated with a lower risk of psychiatric disorders.

But these other groups were associated with a higher risk of psychiatric disorders:

• Bronchial asthma alone
• Allergic rhinitis alone
• Bronchial asthma plus allergic rhinitis
• Bronchial asthma plus atopic dermatitis
• A combination of all 3 allergic diseases above

Bronchial asthma was associated with the risk of individual psychiatric disorders, such as dementia, anxiety disorders, depressive disorders, eating disorders, bipolar disorders, sleep disorders, and psychotic disorders.

Results showed the association between overall allergic diseases and the risk of psychiatric disorders, which echoed the findings of other studies on the association between overall allergic or atopic diseases and the risk of psychiatric disorders. Several studies have reported the associations between bronchial asthma or other atopic diseases and psychiatric disorders, such as affective disorders, anxiety disorders, schizophrenia, substance-related disorders, autism-spectrum disorders, or attention deficity hyperactivity disorder.

The underlying mechanism of the association between allergic diseases and psychiatric disorders remains unclear, but researchers speculated that inflammation may be a common link.

They also found that oral prednisolone usage was associated with a lower risk of developing psychiatric disorders in patients with bronchial asthma. They also found that usage of certain asthma drugs like leukotriene receptor antagonists or the drug aminophylline, with or without prednisolone, also was linked to a lower rate of psychiatric disorders. Why that is so is not known and needs further study, they said.

Reference

Tzeng NS, Chang HA, Hsiang CH, et al. Increased risk of psychiatric disorders in allergic diseases: a nationwide, population-based, cohort study [published online April 24, 2018]. Front Psychiatry. doi: 10.3389/fpsyt.2018.00133.