There is a lack of epidemiological evidence on the prevalence and incidence of mental health disorders in adolescence in Croatia. Depressive disorder and paranoid symptoms have been demonstrated to be closely related in adult community samples or patients with adult depression. The present study used a cross-sectional design to evaluate a sample of Croatian adolescents.

Examine the prevalence of paranoid symptoms in adolescents attending grammar school as a preliminary study of clinical characteristic of depression in adolescence.

A sample of 450 individuals, average age 15.7 (SD=0.45); female 232 (51.6%), male 218 (48.4%). The screening was followed by the use of a structured psychiatric interview (HAMD-21), which was administered to confirm the presence or absence of depression disorder. Item paranoid symptoms were administered to evaluate the level OD symptoms (0–none; 1–suspicious; 2–ideas of reference; 3–delusions of reference and persecutions).

A total of 450 participants were screened, using HAMD-21, paranoid symptoms occurred (44.9%). Depressed adolescents: moderate, severe and very severe, defined as more than 14 points in HAMD-21 presented paranoid symptoms 68.1%, and non-depressed 32.2%.

The depressive group displayed more frequent and intense paranoid symptoms than the control group (P<0.001). Among non-depressed the incidence of paranoid symptoms is a surprisingly high. This could be the consequences of the war in Croatia, transition, as well as the influence of social networks on adolescent communication. This requires future studies.