Lexington, Ky. – The rapid expansion in medical marijuana use means psychologists need to better understand the drug’s effects, a noted cannabis researcher and experimental psychologist told a packed house at the Kentucky Psychological Association’s annual convention in late October.
But Ryan Vandrey, Ph.D., also said more questions than answers remain about what conditions cannabis might help and whether the negative effects outweigh the positive.
“There’s not a lot of good science behind the medicinal use of cannabis,” said Vandrey. “We know about the acute and chronic effects of cannabis use and that’s about it.”
Vandrey is an associate professor at the Johns Hopkins University Behavioral Pharmacology Research Unit. His research includes controlled laboratory studies with volunteers, clinical trials, web-based surveys and studies of populations that have used cannabis for medicinal purposes.
That research points out the many variables that surround the use of cannabis: Many different types exist and it can be taken in a variety of ways, including as a vapor, in food or smoked. Vandrey is studying those variables, including the different effects if cannabis is taken as an edible or a vapor and the differences that 10-, 25- and 50-milligram doses have on participants.
But so much research remains to be done, Vandrey said, that medical professionals have few solid facts to go on when trying to decide if cannabis could help a patient.
Medical marijuana is legal in 29 states and the District of Columbia. But because federal law classifies it as a Schedule 1 drug with no accepted medical use, research into the drug is tightly controlled and difficult to accomplish. “It’s different than a normal drug,” Vandrey said, pointing out that manufacturers must study the safety and effectiveness of a “normal drug” before it’s allowed on the market. That’s not required for cannabis.
A study released in early 2017 by the National Academies of Sciences, Engineering and Medicine says that cannabis has the potential to help with certain medical conditions, but needs to be rigorously researched with expanded, well-funded studies. “The big question is, is it a cure-all or snake oil?” Vandrey said.
He said it appears that cannabis doesn’t help patients with dementia or depression associated with pain, but there’s conclusive evidence that it can help patients with multiple sclerosis, chronic pain and nausea from chemo-therapy, as well as moderate evidence that it can help with sleep dysfunction.
Sleep psychologist Deirdre Conroy, Ph.D., said in a phone interview that she has many patients who use marijuana and say it helps them sleep. But their recreational use of marijuana may affect that.
She found in a community sample of 98 young adults that 39 percent of daily marijuana users had clinically significant insomnia while only 10 percent of those who used marijuana intermittently had insomnia. When researchers removed those who had anxiety and depression, the differences disappeared, said Conroy, clinical director of behavioral sleep medicine program at the University of Michigan.
Conroy said if patients ask about using marijuana to help them sleep she talks to them about available research and the pros and cons. “I take a really neutral approach about whether it’s right or wrong,” she said. “If they feel comfortable and it’s helping, then OK. But I tell them to treat it like it’s any other medication and take it at the same time each day.”
Conroy suggests psychologists educate themselves as much as possible about marijuana use before talking with patients. “The thing is that physicians and psychologists really don’t have any training in this.” She said if patients are using marijuana, their psychologist should talk with them about where they are getting it and how they are using it.
“It may play a big role in what you’re trying to treat,” she said. “You might uncover that they’re cannabis impaired.”
For his part, Vandrey said that “if nothing else works, why not try it?” He cautioned that if psychologists advise someone to use cannabis, they should suggest starting with a small dose and increasing it gradually, “but not until they’re high.”
Other speakers at the Kentucky convention included Arthur C. Evans Jr., Ph.D., chief executive officer of the American Psychological Association. He noted that the organization’s goals include the increased visibility of psychology, building up the APA brand, recognizing psychology as a science and increasing APA’s advocacy.
“What we do is both an art and a science,” said Evans, a clinical and community psychologist. “Not all the answers are in science, but some of them are. We need to pull from all of those.”
About 350 people attended the convention.