Association of psychiatric disorders, asthma and lung function in early adulthood.

Objective: To examine the association between psychiatric disorders, asthma, and lung function in young adults.

Study Design: Data were from the Mater-University of Queensland Study of Pregnancy (MUSP). The study was based on 2443 young adults (1193 male and 1250 female) for whom data were available on psychiatric disorders, asthma, and respiratory function. Life time and last 12 months' generalized anxiety, panic, posttraumatic stress disorder (PTSD), and depressive disorders were assessed using a computerised version of the Composite International Diagnostic Interview (CIDI-Auto). A Spirobank G spirometer system was used to measure forced vital capacity (FVC), forced expiratory volume in one second (FEV(1)), and forced expiratory flow between 25% and 75% of forced vital capacity (FEF(25-75%)).

Results: Participants with mental health disorders were more likely to have experienced asthma before or to use asthma medication at 21 years. However, for both males and females, life time and last 12 months' experience of generalized anxiety, panic, PTSD, and depressive disorders were not statistically significantly associated with FVC, FEV(1), and FEF(25-75%), except a modest association with major depressive disorders for males.

Conclusion: There is an association between mental health and asthma, but the relationship between mental health and lung function appeared to be confounded by the respondent's gender. More narrowly based prospective studies are required to determine the causal pathway between mental disorders and asthma.