OBJECTIVE: To study the frequency of borderline mental disorders in children of secondary general education schools. MATERIAL AND METHODS: We examined 1013 male and female schoolchildren, aged 12-14 and 15-17 years. In the first stage, the they completed a screening questionnaire to estimate the presence of a range of psychosomatic syndromes. An analysis of medical history and clinical examination were performed as well. The second stage included medical examination using DAWBA for the children with total scores on The Strengths and Difficulty questionnaire >/= 16; with the score >/= 6 on the emotional scale and with the score