INTRODUCTION: According to WHO, depression, anxiety and behavioural problems are major causes of illness and disability among adolescents. Recognition of such disorders is crucial for social functioning, physical and mental health, and the ability to lead fulfilling lives.

AIM(S): This study examined the prevalence of mental and behavioural problems in adolescents, with a focus on gender differences.

METHOD(S): The study included data of 168 individuals (56% girls) aged 15-18 years from Kraków, Poland, and the surrounding area, participants of the Kraków birth cohort study. Mental and behavioural problems were assessed using the Youth Self-Report (YSR) for ages 11-18, 2001 version, a widely used self-report measure of adolescent mental health.

RESULTS: The most common problem was anxiety/depression (12.5% of total population), which is a component of the broader internalizing problems that were observed in 10.1% of the total population. Overall, boys exhibited a slightly higher prevalence of mental and behavioural difficulties compared to girls, as they more frequently showed internalizing problems (13.5% of boys vs. 7.4% of girls) and externalizing problems (6.8% of boys vs. 5.3% of girls). Among boys, the most frequently reported problems were anxiety/depression (20.3%), and, based on DSM-oriented scales, DSM-classified anxiety (14.9%). In the group of girls, the most common issues were withdrawn behaviour (8.5%) and aggressive behaviour (7.4%). Regarding DSM-oriented scales, affective problems were most common among girls (8.5%). Boys had significantly higher prevalence of anxiety/depression (p = 0.007) and DSM-classified anxiety (p = 0.017) compared to girls.

CONCLUSIONS: These findings highlight the importance of adolescent mental health screening, with attention to gender-specific symptom patterns. Increasing awareness and providing appropriate support may help improve mental health, social functioning, and overall quality of life in late adolescence.

FINANCIAL SUPPORT: The study was funded by project N41/DBS/000725.