NOEL KING, HOST:
All right. Here in the U.S., a small but growing number of states are allowing medical marijuana to treat severe forms of autism. That's raised the hopes of some parents whose kids are autistic, but there's not a lot of science about the benefits and risks of marijuana use for these children. Lynn Arditi from the Public's Radio has the story.
LYNN ARDITI, BYLINE: It's midafternoon. And inside a raised ranch in Rhode Island, Kristal and Chris's 13-year-old son is just getting home from school. We're not using the family's last name to protect their privacy.
CHRIS: How was school?
DYLAN: No, bad.
ARDITI: Bad, Dylan says. He's a skinny kid with glasses, still small enough for his mom to wrap him in a bear hug if he gets out of control. He's had a lot of bad days. Dylan's parents review the daily reports the school sends home.
KRISTAL: So on this particular day, he had 27 instances of property destruction. He had 25 incidences of aggression. He had only one self-injurious behavior, which is - that's pretty low. They just...
ARDITI: These behaviors all can be associated with autism spectrum disorders. Symptoms can range from social awkwardness to a complete inability to communicate. In Dylan's case, his symptoms seem to defy treatment with traditional medicines.
KRISTAL: And you would think a lot of the medications he's been on would tranquilize a horse.
ARDITI: He's tried 16 different drugs, including Ritalin, Klonopin and Abilify.
KRISTAL: We gave him hundreds in dollars worth of berries and oils.
ARDITI: Nothing worked. Last winter, his behavior became so out of control he was hospitalized for nearly five weeks. But Kristal and her husband are finding reasons to be hopeful in online posts from other parents of autistic children.
KRISTAL: (Reading) Had to share this behavior chart from my son's...
ARDITI: Kristal is reading another mother's Facebook post about her autistic child's experience with medical marijuana.
KRISTAL: (Reading) The circled area highlights the major drop in behaviors. The difference between then and every single summer in the past and now - medical marijuana.
ARDITI: So that's what brings them here today - to Dr. Levine's office in Providence. Dylan starts to get agitated, so his mother tries to soothe him with a hug.
ARDITI: Dr. Levine is a psychiatrist at Women & Infants Hospital who specializes in working with autistic children. And he's open to seeing if medical marijuana can help Dylan.
TODD LEVINE: In some ways, I think about it like cancer care. If your kid has cancer and you're failing chemotherapy and someone at NIH says, we have an experimental drug, you'll go.
DAVID AMARAL: The research basis for a lot of the hopes for using medical marijuana for autism - it's really minimal.
ARDITI: That's David Amaral. He's research director of the MIND Institute at UC Davis in California.
AMARAL: I mean, there's very meager clinical evidence, you know, for effectiveness.
ARDITI: Meager evidence because there have been no large clinical trials to determine whether marijuana or its compounds are effective or safe in treating children with autism. Amaral says some research has linked a chemical in marijuana that gets you high, known as THC, to an increased risk of developing psychotic disorders like schizophrenia. That's one reason why New York doesn't allow medical marijuana to treat psychiatric disorders.
AMARAL: Unless there's a clinical trial that's done in the right way and showing the safety, No. 1, of the drug and then the benefit of it, you know, it may be that families are wasting their time and maybe exposing their family members to, potentially, a dangerous situation.
ARDITI: That's not to say that marijuana doesn't hold promise for autism treatment. In fact, the first large-scale clinical trial in the U.S. is underway at the Albert Einstein College of Medicine in New York. But parents like Kristal and Chris aren't waiting. In their kitchen, Kristal shakes a medicine bottle filled with homemade marijuana oil.
KRISTAL: OK. Do your medicine real quick.
DYLAN: No, [expletive] you.
ARDITI: Kristal uses a plastic dosing syringe to draw out 25 milligrams of homemade cannabis-infused olive oil and squirts it into Dylan's mouth. And already, his dad Chris says, they feel like it's working.
CHRIS: I notice in the morning he's been a little easier to get along with. He's not as angry. He's not waking up angry. He's waking up and, you know, just getting ready and doing his thing and...
DYLAN: (Yelling) Dad.
CHRIS: ...And asking to get dressed and asking for breakfast where it was a lot of yelling and swearing and I hate you and this and that.
ARDITI: These reports from parents, along with input from local doctors and a review of the medical literature, helped persuade Rhode Island health officials to add autism as a qualifying condition for medical marijuana. Dr. Nicole Alexander-Scott is director of the health department.
NICOLE ALEXANDER-SCOTT: Severe autism in particular is not a curable disease, and there are very few other treatment options. So there is a compassionate care element to this.
ARDITI: Rhode Island's new regulations require doctors to first try the FDA approved medications and consult with a child psychiatrist or pediatric neurologist before approving children for medical marijuana. Besides Rhode Island, at least six other states have added autism to the list of debilitating conditions that can qualify patients, including children, for medical marijuana. For NPR News, I'm Lynn Arditi in Providence.