Objective. Clinical analysis of affective disorders in the structure of acute transitory psychosis in adolescents and young adulthood. Material and methods. We examined 40 patients, 12 men and 28 women, mean age 18±1.3 years, with acute transitory psychosis (ICD-10 item F23). Psychometric scales PANSS, HAMD-21 and YMRS were used for assessment of patient’s mental state. Results and conclusion. Marked affective disturbances were characteristic of acute psychotic disorders. The inversion of depressive affect was more frequently observed in psychoses with the symptoms of schizophrenia compared to those without schizophrenic symptoms. Mixed mania with the following residual affective symptoms may be considered as a predictor of the repeated psychotic episode. The results obtained in the study allow to classify 25% of the cases as atypical onset of schizophrenia that gives grounds to prescribe supportive therapy after the clinical reduction of the first psychotic episode.