Inclusion Criteria:

• Aged 6-18 years
• Generally healthy and a score of ≥ 18 on the Aberrant Behavior Checklist in the context of one or more Axis I Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) childhood psychiatric disorders, including conduct disorder, oppositional defiant disorder, disruptive behavior disorder, autism, pervasive developmental disorder, attention deficit disorder, schizophrenia and bipolar affective disorders
• Children's Global Assessment Scale (CGAS) score ≤ 60
• Not previously treated with an antipsychotic; individual subjects with remote, brief prior antipsychotic exposure may be considered for enrollment by the PI on a case by case basis
• Patient assent and informed consent obtained from the parent or guardian
• No clinically significant (based on PI determination) changes in permitted medications (e.g., stimulants and selective serotonin reuptake inhibitors [SSRIs]) for approximately 1 month prior to Baseline evaluations

Exclusion Criteria:

• Active suicidality or primary dx of major depressive disorder
• Any lifetime use of antipsychotics or non-serotonin selective reuptake inhibitor (non-SSRI) anti-depressants

• The presence of any serious medical disorder, based on PI determination, that may confound the assessment of relevant biologic measures or diagnoses, including:

  • significant organ system dysfunction;
  • endocrine disease, including type 1 or type 2 diabetes mellitus;
  • coagulopathy;
  • anemia;
  • or acute infection.
• Subjects regularly taking any glucose lowering agent, lipid lowering agent, exogenous testosterone, recombinant human growth hormone, or any other endocrine agent that might confound substrate metabolism, oral glucocorticoids (glucocorticoid inhalants and nasal sprays are permitted), antihistamines, sedating antihistamines (non-sedating antihistamines such as but not limited to Claritin (loratadine) and Zyrtec (cetirizine) are permitted), and certain mood stabilizing agents, as some medications may themselves worsen or otherwise alter weight gain, glucose and lipid regulation or otherwise make it difficult to assess the effects of the antipsychotic alone; (note that exposure to many psychotropic agents including stimulants and SSRI's is permitted in order to maintain the generalizability of the sample);
• Intelligence quotient (IQ) < 70 (based on school records and/or evaluation by clinician)
• current substance abuse
• Past history or currently has dyskinesia
• Stimulant dosage significantly higher (per PI judgment)than the equivalent of approximately 2mg/kg/day methylphenidate equivalent dose.