Risperidone for Irritability in Autism Spectrum Disorder

Key inclusion criteria were: (a) presence of PDD (autism, PDD-NOS, Asperger’s disorder) established by DSM-IV-TR clinical criteria¹ and corroborated by the Autism Diagnostic Interview-Revised (ADI-R);^{36 (link)} (b) age 4 to 13 years inclusive; (c) ≥ 18 on the Irritability subscale of the parent-rated ABC; ^{37 (link),38 (link)} (d) CGI—Severity score ≥ 4; (e) medication free for two weeks for most psychotropic drugs, and for four weeks for fluoxetine and/or depot neuroleptics; (f) IQ ≥ 35 or mental age ≥ 18 months as assessed by Stanford Binet, Leiter International Performance Scale, or Mullen Scales of Development; and (g) if taking anticonvulsant, seizure-free for ≥ six months and with stable dose for four weeks. Exclusion criteria included (a) positive Beta HCG pregnancy test for girls; (b) prior adequate trial of risperidone; (c) other PDD (i.e., Rett’s disorder, Childhood Disintegrative Disorder); (d) lifetime diagnosis of schizophrenia, other psychotic disorder, bipolar disorder, or current diagnosis of major depression, obsessive compulsive disorder, or substance abuse; (e) significant medical condition (e.g., heart, liver, renal, pulmonary disease), unstable seizure disorder, or significant abnormality on routine laboratory tests.^{12 (link)}