Schizophrenia usually begins in adolescence or early adulthood and affects approximately1% of the population. EOS begins before the age of eighteen, while VEOS begins before the age of thirteen. Since etiopathogenesis remains unclear, there are various theories about the emergence of schizophrenia: the dopamine theory, the genetic theory, the psychodynamic theory, the environmental theory and other. Schizophrenia is a multidimensional disease characterized by heterogeneous symptoms. The psychotic symptoms are present in children and adolescents even before the diagnosis of the disease. The symptoms are divided into positive, negative and disorganisation symptoms. The expression of symptoms in children differs from those in adults due to the cognitive variation of different ages. The delay of the cognitive development is quite often in EOS. The cognitive impairment is a basic symptom of schizophrenia and it has an influence on the course and recovery. DSM-V define the criteria for the diagnosis: delusions, hallucinations, disorganized speech or behaviour, and negative symptoms. The indicators of a worse outcome are: worse cognition, male sex, earlier beginning, poor economic condition, long non-treated period, previous lower social adjustment, and negative symptoms. The most common comorbidity is drug abuse. The conditions considered for differential diagnosis are: general medical conditions, other psychotic disorders, pervasive developmental disorder and autism. Therapy include: antipsychotics, psychoeducation and psychotherapy. Antipsychotics are the first-line therapy, and the atipycal antipsychotics are the first choice. Typical (classical) and atypical (newer) antipsychotics are used in therapy. It is necessary to include psychotherapy, particularly cognitive therapy and psychoeducation.