Allergies Linked to Increased Risk of Psychiatric Disorders

Individuals with allergic diseases such as asthma, allergic rhinitis, and atopic dermatitis are at higher risk for developing psychiatric disorders, according to a study published last spring in Frontiers in Psychiatry. The study was led by Nian-Sheng Tzeng, M.D., an assistant professor of psychiatry at Tri-Service General Hospital in Taipei, Taiwan.

The subjects were selected from the database of the Taiwan National Health Insurance Program. They included 186,588 patients who had allergic diseases and 139,941 controls matched for sex and age; 5,038 (10.8 percent) of the allergy group developed psychiatric disorders compared with 9,376 (6.7 percent) in the control group.

The researchers found that patients with atopic dermatitis alone and allergic rhinitis plus atopic dermatitis showed a lower risk of psychiatric disorders, but the other four groups studied—bronchial asthma alone, allergic rhinitis alone, bronchial asthma plus allergic rhinitis, and bronchial asthma plus atopic dermatitis—and the combination of all these allergic diseases were associated with a higher risk of psychiatric disorders.

Results from the Taiwan study echo the findings of similar research that demonstrates a link between allergic diseases and the increased risk of psychiatric disorders. In the October 14, 2016, issue of BMJ Open, for example, lead author Lene Hammer-Helmich, Ph.D., Real World Evidence Lead for Depression for Copenhagen-based Lundbeck Pharmaceuticals, reports that Danish children with these conditions had more emotional, conduct, and hyperactivity problems than children without symptoms of these diseases.

In an interview with Psychiatric News, Alex Dimitriu, M.D., a sleep medicine specialist and founder of Menlo Park Psychiatry and Sleep Medicine, pointed out that allergies can indeed impact mental health, at the very least because of the effect they have on sleep.

“Nasal congestion can often lead to mouth breathing and possibly bring on or worsen sleep apnea, and can result in significant next-day fatigue,” he explained. “Furthermore, many allergy medications can cause fatigue and drowsiness.” Certain allergy medications, such as leukotriene inhibitors and oral beta-blockers, can also increase the risk for depression and suicidal tendencies.

“There is a very fine line between depression and fatigue,” Dimitriu continued. “The two share so many common features—such as low energy, low motivation, and decreased ability for enjoyment—and one is often confused for the other.”

Dimitriu said that the feeling of breathlessness or not getting enough air often experienced by asthma sufferers can also mimic anxiety or panic disorder because the symptoms can resemble each other.

A developing field of research is exploring the link between inflammatory conditions such as allergies and psychiatric disorders. In the Nordic Journal of Psychiatry, published online November 6, 2017, study authors led by Jeanette Brun Larsen of the Department of Mental Health at the Norwegian University of Science and Technology, report in “Association of Psychosis, Affective Disorders, and Diseases Affecting the Immune System,” that research has shown indications of altered immune activity in depressed and psychotic patients compared with healthy controls.

A study published in the December 2016 issue of The Journal of Clinical Psychiatry supports these findings. The study, led by M. Soledad Cepeda, M.D., Ph.D., director of epidemiology at Janssen Research & Development, found that people with depressive symptoms had, after adjustment, C-reactive protein levels that were 31 percent higher than subjects with no depressive symptoms. ■

“Increased Risk of Psychiatric Disorders in Allergic Diseases: A Nationwide, Population-Based, Cohort Study” can be accessed here. “Mental Health Associations With Eczema, Asthma, and Hay Fever in Children: A Cross-Sectional Survey” is available here. “Association of Psychosis, Affective Disorders, and Diseases Affecting the Immune System” is located here. “Depression Is Associated With High Levels of C-Reactive Protein and Low Levels of Fractional Exhaled Nitric Oxide: Results From the 2007–2012 National Health and Nutrition Examination Surveys” is posted here.