Objective of the study were: to specify the features of clinical presentations and dynamics of anorexia nervosa (AN) developed in adolescence during the current depression; to study affective disorders preceding the onset of AN and to analyze comorbidity of these two pathologies. We examined 21 female patients, aged from 15 to 17 years old (mean age 16.7±0.8 years). It was shown that depressive symptoms developed 4-11 months (mean 7.9±2.5 months) before the onset of AN. The development of AN was associated with depression and might be considered as one of mechanisms of formation of eating disorders that might be termed as affective mechanism. Thus, we can specify a variant of adolescent/juvenile depression, or depression with eating disorders. The variant represents a protracted depressive state with overvalued ideas to improve body image and to restrict calories which is combined with adynamic affect associated with anxiety, melancholy and dysphoria.