The objective of this study is to assess the efficacy ofSimvastatin in the treatment of autism. 40 children between the ages 4 and 12 years with a DSM-5 clinical diagnosis of autistic disorder and who will be outpatients from a specialty clinic for children will be recruited. The children should present with a chief complaint of severely disruptive symptoms related to autistic disorder. Patients will be randomly allocated into simvastatin (20 mg/day for children below 10 years old and 40 mg/day for children older than 10 ) + Risperidone (1-3.5mg/day) or Placebo + Risperidone (1-3.5mg/day) for a 10-week, double-blind, placebo-controlled study. Patients will be assessed at baseline and after 5 and 10 weeks of starting medication. The primary outcome measure is the Aberrant Behavior Checklist-Community (ABC-C) Rating Scale (Irritability subscale).
IRCT registration information
IRCT registration number:IRCT201602041556N86
Registration date:2016-02-04, 1394/11/15
Name of organization / entity
Roozbeh Psychiatric Hospital, Tehran University of Medical Sciences
Iran (Islamic Republic of)
+98 21 5541 2222
Tehran University of Medical Sciences
Expected recruitment start date
Expected recruitment end date
Actual recruitment start date
Actual recruitment end date
Trial completion date
Simvastatin added to risperidone in the treatment of Autism: a double blind and placebo controlled trial
Simvastatin in the treatment of Autism
Inclusion criteria: DSM-5 clinical diagnosis of autistic disorder; children between the ages of 4 and 12 years old; presence of behavioral problems such as aggression, overactivity or repetitive behaviors (indication of treatment with risperidone).
Exclusion criteria: presence of any active medical problem; any other psychiatric diagnosis except for mild mental retardation; receiving any psychotropic medications during past two weeks prior to the trial; presence of hepatic disease; history of seizure; history of allergy to simvastatin or intolerance of it; neutropenia, anemia or thrombocytopenia and renal disease.
From 4 years old to 12 years old
Groups that have been masked
Target sample size:
Randomization (investigator's opinion)
Blinding (investigator's opinion)
Other design features
Name of ethics committee
Ethics Committee of Tehran University of Medical Sciences
Tehran University of Medical Sciences, Ghods St., Keshvarz Blvd.
Ethics committee reference number
Health conditions studied
Description of health condition studied
ICD-10 code description
Severity of Autism
Baseline and weeks 5 and 10 after beginning of treatment