Objectives:
The aim of the study was to investigate whether the prevalence of self-declared depressive symptoms among adolescents attending secondary schools in Krakow is associated with increased frequency and type of psychoactive substance use, and whether depressive symptoms, viewed as a categorical or dimensional variable, may be important in detecting risk of psychoactive substance use among adolescents.

Methods:
A cross-sectional analysis was performed in a group of 1,515 17-year-old students with the use of the Beck Depression Inventory and an original Stimulants questionnaire.

Results:
The analysis of the risk of using psychoactive substances was carried out in relation to independent variables expressed as continuous variables. In the group of boys, each additional point on the Beck scale increased the overall risk of substance use by 3.3%, cigarette smoking by 2.7%, drinking alcohol by 2.7%, and drug use by 4%. In the group of girls, each additional point on the Beck scale increased the risk of substance abuse – overall by 3.7%, cigarette smoking by 3.6%, drinking alcohol by 3.1%, and drug use by 5.9%. Depressive symptoms, approached as a continuous variable, increase the risk of psychoactive substance use in both boys and girls, in particular a strong relationship is observed in the group of girls with low severity of symptoms.

Conclusions:
The presence of declared depressive symptoms increases the risk of using psychoactive substances, especially alcohol and tobacco, and to a lesser extent drugs, in both boys and girls. The use of a dimensional approach made it possible to identify the relationship between increasing depressive symptoms and psychoactive substance use in the group of girls regarded as ‘healthy’ (‘with a negative screening diagnosis’) in the categorical approach.