6.1. Overview of the results

The results of this study revealed that at epidemiological level, skin prick test positive females exhibit an up to 1.8-fold greater risk of developing lifetime depression when compared with prick test negative subjects. In addition, the corresponding risk increased up to 2.7-fold among females, who had a positive skin prick test together with self-reported allergic symptoms.

Second, when assessing whether the strength of the association between atopic disorders and depression was dependent on the severity of depression, it was found that the risk of depression – defined with the help of doctor-diagnosed lifetime depression and the HSCL-25 depression subscale – increased in line with the increased severity of depressive symptoms in atopic but not in non-atopic females ranging from 3.0 to 4.7-fold. Among males the corresponding statistically significant association was seen only in the highest depression scores (mean HSCL-25 score over 2.0), adjusted OR being even 6.3-fold.

Third, while investigating the hospital admissions due to both atopic and depressive disorders, the results showed that hospital-treated atopic disorders increased the probability of hospital-treated depression up to three-fold, independently of the subjects’ gender and sociodemographic characteristics.

Finally, when examining the association between family atopy variables and depression of the study subjects, the major finding was that maternal atopy or atopies in both parents combined with the subject’s own atopy were the most important predictors of a female proband’s lifetime depression, the odds ratios being over 4-fold. Maternal atopy alone almost doubled the risk of lifetime depression in female probands when compared with families in which no maternal atopy existed. Neither parental nor siblings’ atopies predicted any type of depression in male probands.