Asthma, life events and psychiatric disorders: a population-based study

Although asthma and other chronic physical conditions have been shown to be associated with psychiatric symptoms, the relative contributions of negative life events to this association and impaired quality of life (QOL) are not clear. This is a cross-sectional study of a nationally representative sample of Singaporean adults aged 20-59 (n = 2,847). Individuals were grouped by asthma, other chronic physical conditions, and no chronic physical conditions. Participants were assessed life events (list of threatening experiences questionnaire), psychiatric disorders [schedule for clinical assessment in neuropsychiatry diagnoses of psychiatric disorder including any psychiatric disorder, major depressive disorder (MDD) and generalized anxiety disorder (GAD)], and QOL (medical outcomes study 12-item short form). In multivariate analyses controlling for confounding variables, asthma and other chronic physical conditions, compared to no chronic physical conditions, both showed similarly (two- to four-fold) elevated odds ratio (OR) of association with MDD and GAD. However, the asthma group reported more life events as compared to other chronic physical conditions (OR = 4.33, 95 % CI: 2.09-8.95) or no chronic physical conditions (OR = 7.64, 95 % CI: 3.87-15.06). Life events accounted significantly for excess coexistence of psychiatric disorders with asthma over participants without chronic physical conditions. It also contributed significantly to relatively worse QOL observed among individuals with asthma. In this cross-sectional study, life events among adults in Singapore appeared to mediate the co-occurrence of psychiatric disorders and functional impairment with asthma, more than with other chronic physical conditions. This should be further investigated in longitudinal studies.