Gender differences in negative mood states in secondary school students: health survey in Catalonia (Spain).

Objective: To determine the prevalence of negative mood states in adolescents according to gender, to analyze variability among schools, and to evaluate the associated factors.

Methods: A cross-sectional study with a cluster design was carried out. We administered the High-school students health survey to a sample of 9,340 students (aged 14-16 years) in the third and fourth year of Compulsory Secondary Education in Catalonia, Spain, during the 2005-6 academic year. The main outcome measure was evidence of a negative mood state. A multilevel logistic regression model stratified by gender was used to identify the factors associated with negative mood states and to determine variability among distinct schools.

Results: Approximately 19% of adolescents reported evidence of a negative mood state, with a higher prevalence in girls (25%). The most significant factors associated with negative mood states were "use of tranquilizers" and "having eating disorders" in girls and "not exercising" and "poor self-perception of health status" in boys. In both genders, variability was found among schools in the prevalence of negative mood states (girls: variance = 0.078; p <0.001; boys: variance = 0.079; p = 0.012).

Conclusions: The prevalence of negative mood states in adolescent boys and girls was high. Differences were observed between genders in the factors related to these health states. The variability observed in the prevalence of negative mood states among distinct schools could not be explained by the study variables. Our results emphasize the association between the use of tranquilizers and negative mood states.