Ask around discreetly and you’ll find that cannabis is often used to self-medicate mental health conditions like anxiety, depression, PTSD, and even ADHD. What is less clear, however, is whether that cannabis use provides actual medical benefits. There is also the question of short-and long-term consequences.
“The cannabis industry is so far ahead of us with its marketing—it’s kind of the wild west right now,” says Michael McDonell, associate professor in the Elson S. Floyd College of Medicine at Washington State University Health Sciences Spokane. “There are lots of claims being made that may or may not be true and, in most cases, we don’t have the scientific evidence yet.
“At the same time, researchers have to go through many hoops to do a basic study—to see if the claims they are making are even valid. So, the public doesn’t have the balance of information they need to make an informed decision.”
McDonell is 1 of nearly 100 WSU researchers investigating cannabis since its legalization in Washington state opened the doors for wider study.“We are learning and responding as we go,” he says.
A child psychologist, McDonell works with adolescents who are developing serious mental health problems like schizophrenia, which typically begins in the teens or early twenties. He and other members of his team are evaluating a new program focused on first episode psychosis called New Journeys.
“We want to treat kids when they get their first symptoms of psychosis and are struggling to function—for example, hearing voices or seeing things that aren’t there,” he says. “Instead of waiting until they are hospitalized, jailed, or disabled, we try to intervene with the kids right away.”
Schizophrenia has long been anecdotally linked with cannabis use and there is some evidence for a genetic predisposition and sensitivity to THC.
McDonell says studies show that smoking cannabis worsens symptoms in people with schizophrenia, but it can also lead to psychotic symptoms in those without the disease, especially when using the higher THC products.
“It’s dose dependent,” he says. “The higher the THC dose you get, the worse your psychotic symptoms get.”
In contrast, early evidence suggests that cannabidiol or CBD might help counteract psychosis by regulating certain areas of the brain. In one study, children at high risk for developing psychosis and normal controls were given CBD. In all cases, subsequent brain scans showed the brain areas associated with psychosis were stabilized.
“The bottom line is that we need to fully understand the impacts of THC and CBD on mental health,” McDonell says. “The number of people using cannabis daily is steadily increasing, especially in those of college age.
“In Washington dispensaries, you can buy cannabis products with a THC concentration of 70 percent or more. Using high-potency pot on a daily basis is likely to impair functioning in some way. Also, CBD oil is being promoted as a cure-all but it is not closely regulated by the FDA, so you really don’t know what you’re getting when you buy it.”
McDonell worries that people might turn to cannabis as a solution for mental health problems before they try more conventional treatments. “We have a lot of great evidence-based interventions that work for anxiety and depression,” he says, “And most, especially psychotherapy, don’t have side effects.”
That sentiment is shared by Carrie Cuttler, WSU assistant professor of psychology, who compares cannabis to a Band-Aid that temporarily masks symptoms of mental health problems but does not treat the underlying cause.
Cuttler has conducted numerous surveys and studies examining the effects of cannabis on conditions like anxiety, PTSD, and depression. Using a data-collecting app called Strainprint, her participants self-report symptoms before and after smoking cannabis.
“I’d say the best evidence is for the treatment of PTSD,” Cuttler says. “There’s some indication that using cannabis can reduce nightmares and hypervigilance, and generally improve quality of life.”
For anxiety, the evidence is mixed. “In small doses, THC can reduce anxiety but in high doses, it can increase anxiety or even trigger a panic attack and paranoia,” she says. “So, short-term use might be beneficial but not for the long term.
“If you don’t treat the root cause, the symptoms will keep coming back when the high wears off, and people can become dependent on cannabis,” Cuttler cautions. “It’s much better to seek proper treatment with a clinical psychologist to address the issues that are maintaining these disorders.”
Cuttler reports that it is also very common for people to self-medicate depression with cannabis. Using her Strainprint app, she found that many patients reported a 50 percent reduction in depression symptoms right after cannabis use.
“The problem, however, was the longer they used cannabis to treat depression, the worse their baseline symptoms became over time,” she says. “Again, like a wound festering under the Band-Aid, short-term use may help but long-term could exacerbate symptoms.”
Cuttler says regular cannabis use can interfere with the body’s natural endocannabinoid system, which has a wide range of functions including regulating pain, fear, appetite, stress response, and mood.
“We have THC-like substances in our brain called endocannabinoids that are produced as needed by the body,” she says. “Endocannabinoids contribute to the ‘runner’s high,’ for example.
“One of the reasons we think medical cannabis has so many effects is because the endocannabinoid system is so pervasive throughout the body and brain. If that system becomes dysfunctional, it could leave people more vulnerable to depression and anxiety.
“Scientists are now looking at ways to augment this natural system without the use of THC,” says Cuttler. “They hope to develop drugs that will prevent the breakdown of natural endocannabinoids in order to retain higher levels in the brain. They’re just starting clinical trials and it’s showing potential promise for treatment of conditions like PTSD.”