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.
Gallup.com: “14% of Americans Say They Use CBD Products.”
What to Know About CBD and Schizophrenia
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.
Do your research
“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.”
One additional problem exists with CBD. It is a strong cytochrome p450 3A4 inhibitor, which means it has the potential to slow the metabolism (thus increase the dose, perhaps to toxic levels) of 60% of common medications, including many benzodiazepines, antipsychotics, opioids, antibiotics, heart medications, and even meds for organ transplant rejection (see the list of “substrates” on this Wikipedia page.) While that hemp oil gummy you get at the gas station might have 0-1% CBD (but who knows how much?), a stronger product could cause some real problems for people on many different types of medications. As these supplements become more popular and it’s likely there will be some competition between CBD products at the dispensaries vs the FDA approved forms which will be covered in warnings about interactions, it’s very important for doctors and pharmacists to know about these issues.
Because much of the early research showed that CBD probably attenuated the psychotic effects of THC in different strains of marijuana, most of the completed studies of CBD have been in schizophrenia as an additional treatment on top of standard medications and therapies. The largest was of a randomized controlled trial of 88 people by McGuiare et al showing significant improvement in cognitive processing and lower levels of psychotic symptoms such as hallucinations.
Hemp-derived CBD oil is also sold as Hemp oil in all sorts of forms over the counter with almost no regulation and at dispensaries in states that have them. You can get anything from gummies to drops to vape oils to dog biscuits. Unless you get the oil from a regulated dispensary (or are somehow prescribed the FDA-approved version), it’s unclear how much CBD oil is actually in the product you are consuming. The real stuff tends to be expensive ($70-120 for a couple of ounces). Another very important thing to know is that cannabis oil, available from dispensaries, is not the same as CBD or cannabidiol oil, and is usually very high in THC. You absolutely do not want to mix up these two substances.
What are the downsides of CBD, besides the expense and the very real possibility of confusing it with cannabis oil? FDA-approved Epidiolex has a warning to watch for liver damage, and large amounts of CBD in mice is toxic to the liver (by a lot, compare 20 mg/kg recommended dose of Epidiolex to 614 mg/kg that typically induced liver damage in the mice. So if you have the means to purchase large amounts of CBD oil, I certainly would not recommend drinking 30 grams of it at a time.
Another study of 42 people back in 2012 also showed some benefit for improving both hallucinations/delusions and disordered thinking in schizophrenia. A study of 36 folks with chronic, stable schizophrenia symptoms on a somewhat lower dose of CBD showed no difference between CBD and placebo with either positive effects or any bad side effects other than a little sedation. All told that’s less than 200 people. It’s certainly interesting, perhaps even promising, and while we don’t know precisely how it works, it doesn’t seem to work like any of the other medications used for schizophrenia, and it also doesn’t have many of the side effects of other meds (though without long term studies, we can’t assess longer-term side effects).
THC is known for causing the psychoactive “high” of the marijuana experience, which can extend to paranoia, but can also perhaps aid pain relief and induce sleep and relaxation, at least the short term. CBD is short for cannabidiol, and it does not cause a high. A form of CBD, Epidiolex, was recently FDA approved for the treatment of seizures associated with certain rare conditions in childhood, and is a schedule V drug (this is relatively low restriction, with schedule I being illegal things like heroin, and schedule II being many prescription opiates and stimulants with higher potential for abuse).
In Massachusetts and several other states, cannabis products (with some regulation) are legal for both medical and recreational use. While cannabis as a plant has hundreds of chemicals called cannabinoids, many of which may have medicinal, toxic, or psychoactive effects, the two we know the most about are THC and CBD.
Negative symptoms of schizophrenia include blunted emotions, a decrease in the frequency of speech, a deterioration in the ability to plan, start or continue any activity, and a reduction in the perception of positive emotions or interest. These symptoms can cause severe problems in social interaction and daily life.
These understandings have driven the attention of scientists to provide more scientific evidence on the effects of CBD on patients who suffer from schizophrenia.
The opposite effects of THC and CBD
The dose-response curve was also observed in healthy volunteers subjected to anxiety induced by the simulation of public speaking test and by public speaking in real settings. In the first situation, volunteers were asked to speak for a few minutes in front of a video camera, while in the second each subject had to speak in front of a group of other research participants. In both situations, treatment with CBD 300 mg was associated with significant decreases in anxiety symptoms, but this effect was not observed with lower or higher doses.
This led the scientists to carry out a pioneering study to test the effects of CBD on laboratory animals. The stereotypy induced in rats was clearly reduced by CBD, without producing catalepsy, the study has found. The next step was to evaluate the effects of CBD in a patient with schizophrenia. The patient was a chronically psychotic young female who has experienced many adverse effects from traditional antipsychotics, which presented the ethical justification for the first clinical test. After four weeks of treatment, the patient had a marked reduction in her psychotic symptoms.
The third group – cognitive symptoms of schizophrenia include disorganized thinking, slow thinking, difficulty understanding, poor concentration, poor memory, difficulty expressing thoughts, and difficulty integrating thoughts, feelings, and behavior.