Cannabis—let’s talk about it

Cannabis is now legal in many places globally and in the United States—and for good reason! Compared to other legal substances like alcohol, cannabis is safer and many people are able to use it without issues. In addition, we know cannabis also has many medical benefits and clinical applications (chronic pain, severe or persistent muscle spasms, chemotherapy-induced nausea, and specific seizure disorders to name a few). Decriminalization also allows scientists to study the effects, benefits, and risks of cannabis.

But it’s also important to discuss the downsides of cannabis, especially with long-term use. While cannabis is generally less harmful than alcohol, it can have significant negative effects, especially since the concentration of THC in marijuana products (aka: potency) is higher than its ever been before—so let’s talk about it!

What is cannabis doing in my brain?

The main psychoactive molecule in cannabis is delta-9-tetrahydryocannabinol (delta-9 THC) and it interacts with the cannabinoid receptor CBR1R. Activation of CB1 receptor moderates the release of other neutotransmitters like dopamine, glutamate, and GABA. This receptor is found in the cingulate gyrus, hippocampus, cerebellum, cortex, and basal ganglia which are regions in the brain involved with cognition, memory, motor control, and reward.

Is it addictive?

Many people believe cannabis doesn’t cause symptoms of addiction, like dependence and withdrawal. However, cannabis use disorder occurs in approximately 1 in 10 regular users and some studies have shown that as many as a third of daily users meet criteria for cannabis use disorder.

Cannabis use disorder includes many symptoms, for example: using despite physical harm, neglecting social obligations in favor of using cannabis, tolerance, withdrawal symptoms, and an inability to stop. Three major risk factors for developing cannabis use disorder include the amount of THC, how often you consume it, and your age. Withdrawal symptoms include irritability, aggression, anxiety, disrupted sleep, decreased appetite and weight loss, restlessness, depressed mood, and even physical symptoms like shaking, sweating, abdominal pain, and headaches.

What are the concerns with long term use?

Heavy cannabis use can lead to (or worsen) depression and anxiety. It can also worsen social withdrawal, which in turn can intensify loneliness. Many people feel that cannabis actually helped with these symptoms when they first started using it—and it likely did at first. But with persistent use, these symptoms can get stronger.

An interesting study pointed out the connection between cannabis use and loneliness. People who felt lonely were more likely to use cannabis, but in turn, were also more likely to isolate. Since cannabis affects the reward system, the feeling of “boredom” or isolation doesn’t feel as bad. So it’s easier to spend a lot of time doom-scrolling, browsing the internet, and not doing much of anything.

Now there’s a lot of research looking into cannabis and permanent brain damage, so we can’t say anything definitively quite yet. Many studies have found an association between heavy cannabis use and decreased working memory, perceptual reasoning, and inhibitory control—but research is still ongoing.

However, we do know that heavy cannabis use in teenagers is especially bad. There is very strong evidence that teen users are more likely to develop psychotic disorders, depression, and anxiety. In one study, people who first used cannabis prior to the age 15 had nearly a 50% lifetime risk of developing cannabis use disorder later in life.

Should I tell my psychiatrist about my cannabis use?

Please do! Cannabis is a psychoactive drug that can affect your mental health and it can interact with psychiatric medications. So it’s important for your doctor to know so we don’t unintentionally cause more harm.

Even if you use cannabis infrequently or consider yourself a “light” or recreational user, it can be helpful for you and your psychiatrist to monitor changes in use. For example, if you start to use cannabis more frequently than normal, it can be an indication of worsening mood or anxiety symptoms.

Remember, for most people, cannabis use doesn’t cause long term problems and it’s generally less dangerous than alcohol. But like any psychoactive substance, moderation is key. For people who already struggle with their mental health, it’s important to also consider the risks as well.

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