In a study of those who had committed suicide, it was discovered that a significant percentage had suffered from specific seasonal allergies. Is there a link between allergies and suicide?
In an article by Jun Yan in Psychiatric News, a study found that nonviolent suicide rates in women were more than four times higher in spring than any other time of year. For the research, this seemed to correlate to higher tree pollen levels during that part of the year.
Animal studies have shown an increase in anxiety and depression in mice with allergies. When combined with a stressful environment, these mice showed more aggressive behavior.
Other studies have shown that allergies caused by tree pollen doubled the risk of suicide in both men and women. Some of these studies showed the increased risk was not high enough for allergies to necessarily be a determining factor. It was also found that the risk was greater in those who had never been treated for anxiety or depression in the past, meaning there was a reduced risk for suicide in those who had been previously treated for psychiatric disorders.
Allergies affect the immune system and cause a production of chemicals in the brain. These allergy-produced chemicals reduce of the amount of mood-elevating chemicals in the brain which can lead to depression. Current cold and allergy medicines may alleviate symptoms of allergy but do not change the chemical reactions that occur.
Although there have been increased reports of mood changes in allergy sufferers who take certain prescription medications for allergy symptoms, it has not been shown that these medications are to blame for the mood changes. It is quite possibly because the medications do not effect the mood lowering chemicals caused by the allergies themselves.
For those who suffer from seasonal allergies, this does not mean there will automatically be an increased risk for suicide. However, those experiencing symptoms of depression or anxiety more during the spring with the onset of environmental allergies should notify a doctor of any changes in mood.
If a mood disorder occurs with the onset of allergies, treatment is available for those symptoms as necessary. Researchers are still not quite sure exactly what about allergies might cause higher suicide rates. Whether it is an affect of the allergies themselves, the medications or even underlying mood condition, it remains to be seen if there is one specific trigger responsible for the link between allergies and suicide.
Jun Yan; What Accounts for the Link between Allergy and Suicide?; Psychiatric News
Mitchel L. Zoler; Seasonal allergies linked to depression, suicide; BNET Health Publications
P. Qin, et al.; Allergy is associated with suicide completion and a possible mediating role of mood disorder – a population-based study; Allergies