Atypical neuroleptics in the treatment of early onset schizophrenia.

The most complex problems in the use of neuroleptics for schizophrenia are the frequency of nonresponders, the severity of extrapyramidal side effects and tardive dyskinesia, especially in chronic treatment, the persistence of treatment-refractory symptoms, such as negative symptoms. All these problems are more frequent and severe in children and adolescents with early-onset schizophrenia. The classic neuroleptics act on the postsynaptic dopaminergic receptors, especially the D2 receptors, situated in various areas of the Central Nervous System. More recently, the so-called dopaminergic hypothesis of schizophrenia has been criticized and other neurotransmitter systems have been involved, particularly serotonin. The more recently synthesized neuroleptics, with combined action on dopamine and serotonin receptors, have been called atypical neuroleptics; the atypical neuroleptics currently used in clinical practice are clozapine and risperidone. These anti-psychotic drugs are known to be clinically more effective, especially on negative symptoms, have a lower incidence of extrapyramidal side effects, produce significant improvements in some refractory patients. A large number of the studies concern adults; the studies on young populations are much fewer and less rigorous. The aim of this critical review is to describe clinical use of atypical neuroleptics clozapine and risperidone in children and adolescents with early-onset schizophrenia.