NCT04278898 · Stanford University
Targeting the Neurobiology of RRB in Autism Using N-acetylcysteine: Single-dose
What this study is about
The goal of this study is to target the neurobiology of restricted and repetitive behaviors in children with autism spectrum disorder using N-acetylcysteine (NAC), a well-tolerated nutritional supplement that has shown promise for reducing symptom severity in recent small-scale trials.
View original scientific description
The goal of this study is to target the neurobiology of restricted and repetitive behaviors in children with autism spectrum disorder using N-acetylcysteine (NAC), a well-tolerated nutritional supplement that has shown promise for reducing symptom severity in recent small-scale trials. The findings from this research will shed light on the mechanisms of action underlying the clinical benefits of NAC.
Interventions
DRUG
N-Acetylcysteine
N-acetylcysteine Single Dose 2700 mg taken orally
Primary outcome measures
Change in glutamatergic neurometabolites (Glx) measured by proton spectroscopy Magnetic Resonance Imaging (MRI)
Time frame: 1 hour after single dose
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- children between 3 years and 12 years 11 months at the time of consent
- diagnosis of Autism Spectrum Disorder confirmed with the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule-2 (ADOS-2), or Brief Observation of Symptoms of Autism (BOSA), or Childhood Autism Rating Scale- Second Edition (CARS-2).
- at least moderate Restricted and Repetitive Behaviors severity defined by a Children's Yale-Brown Obsessive Compulsive Scale for children with autism spectrum disorder score ≥ 11,
- physical development indicative of prepubescence as defined by the criteria for Tanner Stage 1,
- medically stable,
- passes MR safety screening (e.g., no metal in the body).
Exclusion criteria
- presence of known genetic abnormalities associated with Autism Spectrum Disorder (e.g. Fragile X),
- current or life-time diagnosis of severe psychiatric disorder (e.g., schizophrenia),
- presence of significant medical problems that would interfere with participation,
- the inability of at least one caregiver to speak/read English to a sufficient level to complete study requirements and materials,
- individuals taking antioxidant agents and glutathione prodrugs, or
- the inability/unwillingness to swallow an agent during the screening visit.
Where
- Stanford, California
Collaborators
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 15, 2026 · Source of record for eligibility and locations