Edited by: Hans-Uwe Simon
Allergy is associated with suicide completion with a possible mediating role of mood disorder – a population-based study
Version of Record online: 8 DEC 2010
© 2010 John Wiley & Sons A/S
Volume 66, Issue 5, pages 658–664, May 2011
How to Cite
Qin, P., Mortensen, P. B., Waltoft, B. L. and Postolache, T. T. (2011), Allergy is associated with suicide completion with a possible mediating role of mood disorder – a population-based study. Allergy, 66: 658–664. doi: 10.1111/j.1398-9995.2010.02523.x
- Issue online: 7 APR 2011
- Version of Record online: 8 DEC 2010
- Accepted for publication 11 November 2010
- mood disorder;
- population study;
- suicide risk
To cite this article: Qin P, Mortensen PB, Waltoft BL, Postolache TT. Allergy is associated with suicide completion with a possible mediating role of mood disorder – a population-based study. Allergy 2011; 66: 658–664.
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.