Major depression and allergy: does neuroticism explain the relationship?

OBJECTIVE To determine the association between major depression, neuroticism, and self-reported allergy among adults in the community. METHODS Data were drawn from the Midlife Development in the United States Survey, a nationally representative sample of 3,032 adults age 25 to 74. ANOVA and multiple logistic regression analyses were used to determine the association between depression and allergy and the role of neuroticism in these relationships. These links were also examined by gender. RESULTS Among adults in the community, major depression was associated with a significantly increased likelihood of allergy (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.14-1.98). Higher levels of neuroticism were also significantly associated with increased likelihood of allergy (OR, 1.22; 95% CI, 1.04-1.43). Among women, major depression was associated with a significantly increased likelihood of allergy (OR, 1.67; 95% CI, 1.15-2.41), and this relationship persisted after adjusting for demographic characteristics and neuroticism. Among men, there was no significant relationship between allergy and depression, yet neuroticism was related to allergy (OR, 1.42; 95% CI, 1.42-1.82), which persisted after adjustment for depression. CONCLUSION These data are consistent with results of previous studies showing an association between major depression and allergy among adults and extend these data by providing preliminary evidence suggesting that this association is specific to women and independent of the effects of neuroticism among women. In addition, the data provide preliminary evidence that neuroticism may be related to allergy among men, though no link between depression and allergy was found among men. Future research with prospective, longitudinal studies is needed next to understand the possible biological underpinnings of these associations.