Clozapine demonstrated superior efficacy in treatment-resistant patients with EOS, whereas ziprasidone failed to demonstrate efficacy in the treatment of EOS. Our review also focuses on the onset of action and weight gain associated with AAPs. The data on onset of action of AAPs in pediatric psychiatry are scanty and inconsistent. Olanzapine appears to cause the most significant weight gain in patients with EOS, while ziprasidone and aripiprazole seem to cause the least.