Does cannabis interact with antidepressants or lithium?
Cannabis and antidepressants
Cannabis or marijuana can interact with tricyclic antidepressants (TCAs), such as amitriptyline, imipramine and dothiepin.
Both cannabis and TCAs can cause an abnormally fast heartbeat (tachycardia) and high blood pressure (hypertension). There’s also a risk of other side effects, such as confusion, restlessness, mood swings and hallucinations.
There’s a risk that using cannabis while you’re on any of these medicines could lead to problems such as tachycardia, even if you don’t already have a heart condition.
Little research has been done into the interaction of cannabis with other types of antidepressants, such as SSRIs.
Cannabis and lithium
Lithium is used to treat bipolar disorder, a condition where people can switch between depression and extreme excitement and agitation (mania).
There’s little evidence to suggest that people who use cannabis should normally not take lithium, but this hasn’t been properly researched.
Side effects of cannabis
It’s not clear how often cannabis itself can cause anxiety or depression, but research suggests this can happen.
It’s therefore recommended that if you’re anxious or depressed and you use cannabis regularly, you should try giving up and see if that helps.
Tachycardia, dizziness, anxiety, drowsiness, nausea and vomiting, difficulty sleeping and confusion are all possible side effects of cannabis.
These side effects can also be caused by certain antidepressants, so using cannabis at the same time can make them worse.
If you have any concerns about the medicines you’re taking, talk to your GP or pharmacist.
You can also phone NHS 111 or Talk to Frank, a friendly confidential drugs helpline, on 0300 123 6600.
- Antidepressant drugs
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Page last reviewed: 27 March 2018
Next review due: 27 March 2021
Cannabis or marijuana is usually smoked and typically mixed with tobacco. It can interact with certain types of antidepressants, such as tricyclic antidepressants (TCAs), which share similar side effects.
Mixing Marijuana and Antidepressants: What You Need to Know
You don’t need a study to recognize that mood elevation is one of the prime reasons people consume marijuana. It is, after all, called “getting high.” Still, studies do exist, such as one in the journal Depression and Anxiety that notes that easing anxiety is among the top five symptoms for which people in North America use medical marijuana.
When a blue mood persists or anxiety is chronic, however, many people choose to take an antidepressant medication, such as fluoxetine (Prozac), citalopram (Celexa), or sertraline (Zoloft). According to the American Psychological Association , nearly 8% of people between the ages of 20 and 39 have taken prescription antidepressants in any given month.
If you’re already among this population, or you’re considering trying a prescription antidepressant and you’re a regular cannabis user, you’ll probably want to know how these meds and weeds interact. Do they enhance each other? Undermine the benefits? Are there any dangers to continuing weed use while you’re on an antidepressant?
Daniele Piomelli, Ph.D. , director of the University of California , Irvine, Center for the Study of Cannabis , said, “Truth be told, there is precious little work done” on this topic.
“There have been a few trials that looked at CBD or THC for anxiety and depression going back to the 1980s,” he said. “In general, the results have been positive, showing that cannabis has some effectiveness in countering mood disorders.” But, he added, the number of study participants was so small — just 25 in one case — “that it’s impossible to draw any medical conclusions.”
What we do know, he said, is that our built-in endocannabinoid system (ECS) plays an important role in mood regulation, including stress disorders and major depression. An endocannabinoid called anandamide, which has been dubbed “the bliss molecule,” is especially vital to our body’s ability to cope with stress in a healthy manner.
A study that Piomelli led in 2015 demonstrated that anandamide heightens motivation and happiness. Now, he’s looking at whether an anandamide deficiency might be linked to post-traumatic stress disorder (PTSD).
Synergies for Weed and Antidepressants
This research raises the prospect of synergy between marijuana and antidepressants. Could a few hits of your favorite strain along with 10 or 20 milligrams of paroxetine (Paxil) or Prozac counter distress more effectively than either alone?
“That is very possible,” Piomelli said. “We’ve certainly heard anecdotally from a lot of people that cannabis helps them with stress and depression and I have no problem believing them. But, the endocannabinoid system is a very fine-tuned, delicate machine. It’s evolved over millennia to regulate our ability to deal with stress in a positive way and it can easily be thrown off balance.”
The challenge in self-medicating with marijuana for depression or anxiety is it’s difficult to find the right dose. Too little, and there’s no impact; too much, and especially for novice users, there’s a risk of experiencing a panic attack. Without professional oversight, self-medicators also may overlook some other underlying condition.
“When physicians prescribe antidepressants or antipsychotic drugs,” Piomelli said, “they’re very careful, typically starting out with a very low dose and if that’s insufficient, increasing the dose slowly until the response is satisfactory.
“Now imagine a plant, like cannabis, that comes in a thousand different shapes and forms. You go to a dispensary and you’re relying on budmasters to help you navigate everything.” Even the most astute budmaster can’t guarantee you’ll be able to repeat the experience you had a week ago.
“Reproducibility is complicated,” Piomelli said. “Because cannabis products aren’t regulated by the FDA, you can’t count on consistency. You might find a product that is useful to you but when you go back to the same dispensary and purchase it again, the amount of THC, cannabidiol (CBD) , or other cannabinoids it contains might be slightly different and you’ll have a different response.”
One challenge to researching how cannabis might interact with antidepressant medications has been the difficulty to reproduce conditions for clinical study, argues Daniele Piomelli, Ph.D., director of the University of California, Irvine, Center for the Study of Cannabis. Any variation in the THC, cannabidiol (CBD), or other cannabinoid levels in marijuana could produce different experiences and interactions. (Gina Coleman/Weedmaps News)
How Weed Impacts Potency of Meds
There’s another knotty issue: Namely, experts don’t know how weed affects what’s known as the “pharmacokinetics” properties of antidepressant medication. That term refers to how the body absorbs, processes, and disposes of a drug.
“If cannabis consumption inhibits the metabolization of an antidepressant drug that would essentially increase its potency because there’s more of the drug hanging around the body,” Piomelli said. “This is a very important element of which we really have no understanding.” The lack of data, he said, can put physicians in danger of prescribing an inappropriate dose of an antidepressant medication. And that, in turn, could mean a delay in relieving depression or even a worsening of the symptoms.
To safeguard against this, Piomelli recommended a few things. First, have a frank conversation with your physician about your cannabis use in the past, present, and future. If your doctor isn’t open to this conversation, you’ll probably want to find one who is.
“This is something we have to work on as a society,” Piomelli said. “As a physician, your job is to help your patients feel better. Cannabis is used by millions and millions of people in the U.S. It’s now a legal product in a majority of the states. There’s no excuse for doctors not knowing how it interacts with the body.”
Still, since there’s so much we don’t know about potential interactions between antidepressants and cannabis, Piomelli said that finding the right balance between both substances takes a lot of experimentation and has to be personalized to each patient. “That might not be what people want to hear,” Piomelli said, “but it’s where we are right now.”
The Case Against Quitting Cold Turkey
Whatever you do, Piomelli said, if you decide to start taking an antidepressant, don’t quit cannabis cold turkey, especially if you’ve been a heavy user.
“The effects of cannabis withdrawal include depression, irritability, anxiety, loss of sleep and appetite, even suicidal ideation,” he said. Plus, keep in mind that it takes several weeks for antidepressants to begin working, and even longer to find the optimal dose.
If you intend to cut down your cannabis use as you introduce antidepressants, or, conversely, if you’re currently taking an antidepressant and want to see if you can lower the dose by combining it with nightly vaping, go slow on titrating the dosages of both. As much as you can, try to be consistent in the cannabis products you use.
“If you shift to another kind of cannabis with a higher or lower level of THC, you might imbalance your endocannabinoid system and lose the ability to control your symptoms or precipitate a deeper depression or greater anxiety,” Piomelli said.
You might also want to throw non-psychoactive tools into the mix, like mindfulness meditation, yoga, or tai chi.
“There are lots of things,” Piomelli said, “that don’t come in a pill and can help lift your mood and counter stress.”
Feature image: With antidepressant medication and cannabis use prevalent in segments of the population, what happens when weed and meds are combined? Health experts cannot say for certain. (Gina Coleman/Weedmaps News)
Mixing Marijuana and Antidepressants: What You Need to Know You don’t need a study to recognize that mood elevation is one of the prime reasons people consume marijuana. It is, after all, called