Allergies occur when the immune system identifies certain substances such as pollen, bee venom, nuts or pet dander as harmful and produces proteins known as antibodies to combat them. These antibodies, in turn, lead to the release of certain chemicals that lead to allergy symptoms such as congestion, runny nose, itchy skin, rash or hives. Depression is a medical condition that involves both the mind and the body and is characterized by feelings of sadness, irritability, loss of interest, reduced sex drive, insomnia and changes in appetite.
Incidence of Depression and Allergies
According to statistics published by the National Institute of Health, depression is the No. 1 cause of disability in the United States for individuals between the ages of 15 and 44. It affects 6.7 percent of adults in a given year. At the same time, a USA Today report published in March 2008 states that about 40 million people in the United States suffer from seasonal allergies. A link between allergies and depression can help in the management of both the conditions.
Mechanism
Allergies cause the immune system to release chemicals called cytokines, which are believed to be the major causes of depression and fatigue. According to 2008 USA Today article titled "Seasonal Allergies Could Spark Depression, Fatigue," Cytokines directly affect the central nervous system and lead to the release of a chemical in the brain called IL-1 beta. This chemical induces the feeling of weakness, lethargy, low mood and the inability to concentrate. Insomnia associated with allergies can also lead to depression as the patient's efficiency at day-to-day activities goes down. Another study published in the September 2002 edition of Psychiatric News reported similar findings in patients with ragweed allergies.
The Opposite Effect
Several studies have suggested that just as allergies can lead to anxiety and depression, the opposite is also true. Depressive disorder symptoms such as fear, anxiety and restlessness can also prolong the effect of allergies. A study published in the June 2009 edition of Psychoneuroendocrinology states that extended stress and anxiety can prolong the allergic responses associated with allergic rhinitis and worsen the asthma associated with it.
Treatment
The apparent connection between allergies and depression plays an important role in designing a treatment plan for patients with these conditions. Treatment of underlying allergies might benefit a patient with depressive disorder. The article published in USA Today recommends nasal saline and steroid drops instead of antihistamines to treat allergies and help patients sleep better and feel better.
Prevention
Prompt treatment of allergies and avoiding the allergens is the best way to prevent allergy-associated depression.
References
- National Institute of Mental Health: The Numbers Count: Mental Disorders in America
- USA Today: Seasonal allergies could spark depression, fatigue
- Psychiatric News: Ragweed Allergy May Trigger Depression, Malaise
- "Psychoneuroendocrinology"; How Stress and Anxiety Can Alter Immediate and Late Phase Skin Test Responses in Allergic Rhinitis; Janice K. Kiecolt-Glaser et al; June 2009
