Behavioural factors enhancing mental health - preliminary results of the study on its association with physial activity in 15 to 16 year olds.

Introduction: Reliable information on the influence of behavioural factors on adolescent mental health may help to implement more effective intervention programmes.

Objective: The objective of the study was to determine whether physical activity influences the variability of selected indices of mental health.

Methods: The study comprised 2,015 students aged 15-16, who were investigated as part of the HBSC survey (Health Behaviour in School-aged Children) in the 2013/14 school year. The dependent variable was the mental health index GHQ-12 (0-36 points) and its two domains (social dysfunction, anxiety and depression). Physical activity was measured with the MVPA (moderate-to-vigorous physical activity). Multivariable linear models were estimated, with overall GHQ index and partial indices as dependent variables.

Results: Adolescents reported a mean GHQ-12 score of 12.57 (±7.06). In a multivariable analysis, the pressure with school work along with gender resulted to be the main GHQ-12 predictors. School achievements and a high level of physical activity were identified as strong protective factors. Taking into account other factors, the GHQ-12 index falls by 2.13 points when comparing adolescents with an extremely low and high MVPA. Protective effect of physical activity appeared to be stronger in small towns and villages than in big cities and was more visible in the domain of social dysfunction.

Conclusions: Physical activity remains an important predictor of mental health, even when the impact of sociodemographic and environmental factors as well as the respondents' school achievements are considered. Researches of such types, taking into account more complex determinants, wider behavioural factors' spectre as well as other outcome measures connected with teenagers' mental condition, should be continue.