Allergy is associated with suicide completion with a possible mediating role of mood disorder - a population-based study

Allergy. 2011 May;66(5):658-64. doi: 10.1111/j.1398-9995.2010.02523.x. Epub 2010 Dec 8.


Background: With increasing research suggesting a role of allergy on suicidality, this study, on a population level, delved into how allergy affects risk for suicide completion in the context of mood disorder and other factors.

Methods: Based on the entire population of Denmark, we included 27,096 completed suicides and 467,571 live controls matched on sex and age with a nested case-control design. We retrieved personal information on hospital contacts for allergy and other variables from various Danish longitudinal registries and analyzed the data with conditional logistic regression.

Results: We noted that 1.17% suicide victims, compared with 0.79% matched controls, had a history of hospital contact for allergy and that a history of allergy predicted an increased risk for suicide completion; however, the effect was confined to allergy that led to inpatient treatment (IRR: 1.59, 95% CI: 1.41-1.80). The increased risk was attenuated somewhat but remained significant when adjusted for personal psychiatric history and socioeconomic status. Meanwhile, we observed a nonsignificantly stronger effect in women than in men, and a significant age difference with a stronger effect for individuals at high ages. Moreover, we detected a significant interaction between allergy and mood disorder - even an antagonism effect of the two exposures. Allergy increased suicide risk only in persons with no history of mood disorder, whereas it eliminated suicide risk in those with a history of mood disorder.

Conclusions: The findings support a link between allergy and suicidality, with a possible mediating role of mood disorder.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Case-Control Studies
  • Denmark / epidemiology
  • Female
  • Hospitalization
  • Humans
  • Hypersensitivity / psychology*
  • Inpatients
  • Male
  • Mood Disorders / psychology*
  • Risk Factors
  • Sex Factors
  • Social Class
  • Suicide*