Introduction Asthma is the most common chronic disease in childhood and has been designated a public health problem due to the increase in its prevalence in recent decades, the amount of health service expenditure it absorbs and an absence of consensus about its aetiology. The relationships among psychosocial factors and the occurrence, symptomatology, and severity of asthma have recently been considered. There is still controversy about the association between asthma and child's mental health, since the pathways through which this relationship is established are complex and not well researched. This study aims to investigate whether behaviour problems are associated with the prevalence of asthma symptoms in a large urban centre in Latin America.

Methods Cross-section study of 869 children between 6 and 12 years old, residents of Salvador, Brazil. The International Study of Allergy and Asthma in Childhood (ISAAC) questionnaire was used to evaluate prevalence of asthma symptoms. The Child Behaviour Checklist (CBCL) was employed to evaluate behavioural problems.

Results 19.26% (n=212) of the children presented symptoms of asthma. We found good evidence of an association between behaviour problems and asthma symptoms (PR: 1.53; 95% CI 1.13 to 2.08. p=0.007) and this association remained statistically significant after adjustment for sex, age, maternal education, income, parental asthma, minor psychiatric disorders in the mother, Alcohol use, allergens in dust and smoking (PR: 1.43; 95% CI 1.10 to 1.85. p=0.01).

Conclusion These results suggest an association between behavioural problems and paediatric asthma, and support the inclusion of mental healthcare in the provision of services for asthma morbidity.