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Autism researchers seek teens, young adults for drug trial

Scientists at Stanford are studying pregnenolone, a neurosteroid that may help treat irritability, sensory abnormalities and social deficits in adolescents with autism.

- By Erin Digitale

Antonio Hardan

Researchers at the Stanford University School of Medicine are seeking teenagers and young adults ages 14 to 21 to participate in a clinical trial of a compound, pregnenolone, that may reduce irritability and associated aggressive behaviors in autism spectrum disorder.

Irritability and aggressive behavior are the No. 1 reason that individuals with autism end up in emergency rooms. Without effective treatment, these behaviors can cause significant problems in daily life for people with autism and their families.

But available treatments have drawbacks. 

“The atypical antipsychotic medications we use to treat mood dysregulation in autism have a lot of side effects,” said lead investigator Antonio Hardan, MD, professor of psychiatry and behavioral sciences. The long-term side effects can include diabetes and involuntary motor movements.

Pregnenolone is a neurosteroid that has previously been shown to alleviate symptoms of other psychiatric conditions such as schizophrenia. Neurosteroids are naturally occurring steroid hormones synthesized in the brain and other organs. Recently, researchers have begun to understand their roles in sending signals to nerves in the brain.

“The biology of neurosteroids in other psychiatric disorders has been studied for about 20 years, but in autism not much is known,” said study investigator Lawrence Fung, MD, PhD, an instructor in psychiatry and behavioral sciences. “This study will give us a chance to understand their role in the pathophysiology of autism.” The trial may also enable the future development of biomarkers for autism, he said.

Some scientists hypothesize that individuals with autism have too much excitatory signaling or too little inhibitory signaling, or both, in their brain circuits. Metabolites of pregnenolone have been shown to increase inhibitory signaling. Thus, pregnenolone may benefit people with autism by “normalizing” the imbalance between excitatory and inhibitory signaling; it could possibly help treat mood dysregulation, sensory abnormalities and social deficits.

“Pregnenolone is very benign and usually very well-tolerated,” Hardan said. “Patients should know that the potential for benefit is modest, but we think it is still worth exploring its value in treating individuals with autism.”

Teens and young adults aged 14 to 21 with autism are eligible to enroll in the trial. Study participants will visit Stanford once every two weeks for the 14-week trial. Participants will be randomized to receive either pregnenolone or placebo and will not know which compound they receive until the 14-week period is over. After that, the subjects who receive placebo in the randomized phase will have the option to start taking pregnenolone.

More information about the trial is available online or by calling (650) 736-1235.

Stanford Medicine integrates research, medical education and health care at its three institutions - Stanford School of Medicine, Stanford Health Care, and Stanford Children's Health. For more information, please visit the Office of Communications website at

2022 ISSUE 1

Understanding the world within us

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