Cognitive deficit in endogenous mental disorders in children and adolescents is studied less than in adults, particularly age of onset influence. There is very few data about the connection between degree of cognitive deficit and age of psychiatric illness onset in children and adolescents. It’s difficult to determine the specificity of cognitive deficits depending on the clinical form of endogenous mental disorders (schizophrenia).

93 patients (11.8±2.3 years) with childhood schizophrenia (F20.8, 26 patients), schizotypical disorders (F21, 59 patients), unspecified schizophrenia (F2x.x, 8 patients). We used adaptation of ICD-10 for RF.

Assessment of degree of cognitive deficit relative to age of onset and diagnosis.

Tests assessing cognitive processes: memory, attention, thinking. Z-scales were used for estimation of cognitive deficit.

Age of onset was divided into three periods: early, preschool and school age. The least degree of all cognitive functions occurs in patients with school age of onset. F20.8 and F2x.x with early and preschool age of onset have severe thinking deficit.

F21 demonstrates decreasing of cognitive deficit degrees in all functions with increasing of age of onset. Degree of cognitive deficit is connected with clinical diagnosis. Patients with F20.8 have strong deficit in all cognitive functions (memory, attention, thinking). F21 patients demonstrate a variety of cognitive deficit degrees including age norm outstrip. F2x.x patients keep intermediate position.

Age of onset might be important in determination of degrees of cognitive deficit. The last depends on diagnosis, age of onset & kind of cognitive process.