OBJECTIVE: To determine the prevalence of depression and anxiety and their associations with body mass index (BMI) among high school students in Qazvin, Iran in 2013-2014.

METHODS: A descriptive and analytical cross-sectional study using cluster-sampling method recruited 1,040 students among high schools in Qazvin, Iran from March 2013 to April 2014. Data were collected using questionnaires including demographic, Beck depression inventory and Beck anxiety inventory, and were analyzed with SPSS-19 by descriptive analyses, t-test, Chi-square and Pearson correlation.

RESULTS: The prevalence of depression and anxiety was 31.8% and 14.9%, respectively and these amounts were significantly higher in girls than in boys (p<0.05). Respondents showed 23.75% and 11.07% mild to moderate symptoms of depression and anxiety, respectively as well as 8.08 and 3.75% severe symptoms of depression and anxiety, respectively. There was a positive and significant association between depression and anxiety (r=0.256, p<0.001) and between depression and body mass index (BMI) (r=0.333, p<0.001), however there was an inverse association between anxiety and BMI (r=0.086, p<0.006).