Editor's note: This article was updated on 1/5/2021.
Many people say CBD helps them manage health issues like pain, anxiety, sleep trouble, and PTSD. CBD is short for cannabidiol, a natural compound in cannabis (also known as marijuana) and hemp plants. It has the same chemical makeup as cannabis but doesn’t cause a high.
In 2018, the FDA approved a form of CBD to treat seizures in children. Scientists are also studying CBD oil -- the most concentrated form -- for dozens of other health conditions, including schizophrenia.
What the Experts Say
Joseph Pierre, MD, a psychiatrist and professor at the University of California, Los Angeles, says CBD’s potential role in schizophrenia treatment starts with tetrahydrocannabinol (THC), the compound in cannabis that causes a high. THC can cause psychotic symptoms in some people, he says. And long-time cannabis users, especially those who start when they’re young, may be more likely to get a disorder like schizophrenia.
“Since CBD opposes some of the effects of THC in the brain, it makes sense it could be useful in treating psychotic disorders,” Pierre says. “There’s also some evidence that CBD has properties similar to antipsychotic drugs.”
But Pierre says people with schizophrenia shouldn’t try CBD on their own. The risks and benefits aren’t clear, and products sold without a prescription don’t always contain what they claim.
He also notes that the FDA doesn’t regulate CBD products.
“We have many FDA-approved medications from plant sources,” Pierre says. “For example, the heart medication digoxin is derived from the foxglove plant. But if someone needs digoxin, I wouldn’t recommend they go pick some foxglove, bake it into a brownie, and eat it.”
Peter Bongiorno, ND, a naturopath and acupuncturist in New York, recommends CBD for some people as part of an approach that includes lifestyle changes, balanced hormones, and lower levels of inflammation. He urges those who take other medicines or who have mental health conditions to “work with someone who has experience with CBD.”
What to Know About CBD and Schizophrenia
If you have schizophrenia but antipsychotic medications don’t work for you or have serious side effects, you might be tempted to give CBD oil a try. But there are some important things to keep in mind.
Because of its link to schizophrenia or psychotic episodes, THC is strictly off-limits if you have schizophrenia or if it runs in your family. So it’s crucial to know what you’re getting. That’s not easy, because the market is flooded with products. Many don’t contain what the label claims, and the terms may be confusing.
- Full-spectrum CBD oil comes from the whole hemp plant. It contains all the compounds called cannabinoids, including traces of THC (0.3% or less). It’s a small amount, but you should still skip this one.
- Broad-spectrum CBD oil doesn’t contain THC but has all the other cannabinoids. Bongiorno says they may help CBD work better.
- Pure CBD oil means 100% CBD. “Pure CBD products are supposed to only have CBD, but unfortunately, even those sold in dispensaries sometimes contain THC or don’t contain any CBD at all,” Pierre says.
- Hempseed oil is tricky. To avoid legal trouble, some manufacturers label CBD oil as hemp oil. Hempseed oil is made from hemp seeds and contains no CBD.
Do your research
Find out how the company grows, tests, and processes its CBD products.
- Check the certificate of analysis, or COA. This shows that each batch is tested by an independent lab. It should say exactly what’s in the product and what isn’t, like toxic metals and pesticides. You can find the CoA online, by email, or with the product. If not, steer clear.
- Ask about sources. The best CBD usually comes from organic plants grown on small farms in the U.S. and Canada.
How much to take
“If you’re going to use CBD for mental health, ask your practitioner for a high-quality version,” Bongiorno says. The amount you take can vary. “The studies tend to use pure CBD, which requires a higher dose. I use CBD with other cannabinoids at lower doses.”
CBD is normally very safe but can have side effects in some people. The most common are dry mouth, feeling dizzy or irritable, anxiety, diarrhea, and nausea. There’s a chance of liver damage at very high doses.
CBD can affect how your body handles other medicines. This means you may have higher or lower amounts in your blood than you should. Penn State University researchers found 60 drugs that interact with CBD or cannabis. Be extra careful if you take blood thinners, heart medicine, or drugs that weaken your immune system after transplant surgery. Pierre says that even some psychiatric medicines, including antipsychotics, could interact with CBD. You should ask your doctor if CBD is safe to use.