Depression affects an estimated 17 percent of American adults each year. Marijuana is the most widely used illicit drug in America. More than 20 million people over age 12 have tried marijuana at least once.
It’s also a popular recreational pastime and medical treatment for nausea during chemotherapy. The question is whether using it to treat depression actually does any good — or if it could even make things worse. We’ll look at some of the evidence on both sides.
Marijuana is the most commonly used illegal drug in America (more than 22 million Americans aged 12 or older have taken it at least once). In addition, more than one out of every five high school students has smoked pot.
And while its use as a medicine dates back thousands of years, since 1970, when researchers first began studying cannabis’ effects on anxiety disorders, hundreds of studies have looked into its potential benefits and side effects. But what about those who suffer from clinical depression? Does smoking marijuana help them feel better? Or does it just cloud their judgment?
Marijuana is not classified as a depressant. Instead, it is considered a psychoactive drug that can have a range of effects on the mind and body. Specifically, it contains compounds called cannabinoids, which can interact with the brain’s endocannabinoid system to produce various effects, including relaxation, euphoria, altered perception, and changes in appetite and mood. While marijuana may have some depressant-like effects, such as slowing down certain bodily functions, it is not classified as a depressant in the same way that alcohol or sedatives are.
This article will examine how marijuana can be used medically and recreationally to treat depression and why people suffering from major depressive disorder might not want to try it.
To start, let’s talk about how marijuana works medicinally. Then we’ll look closely at research that shows whether you should consider giving up your spliff to beat depression. Finally, we’ll discuss the possible adverse health risks associated with smoking weed — including whether it increases depression risk.
But before we delve into our discussion of depression treatments involving marijuana, here are some basic facts about the plant that may prove helpful.
Medicinal Uses
There are two primary compounds found in marijuana plants — delta9 Tetrahydrocannabinol (THC) and cannabidiol (CBD), often referred to collectively as THC. These chemicals affect the body differently and work together to create a euphoric feeling without stoning users.
CBD doesn’t produce mind-altering effects like alcohol because it only binds to specific receptors in the brain, unlike THC, which attaches to all cannabinoid receptors, known as CB1 and CB2. However, CBD reduces animal inflammation by blocking pain pathways, while THC seems to stimulate these same pathways.
Both substances seem to inhibit cancer cell growth, but they do so through different mechanisms, according to a study published in March 2012 in Cancer Prevention Research. Researchers believe CBD inhibits tumor growth via an antioxidant effect, whereas THC stimulates immune cells to fight tumors [Source: Fox].

Although scientists still aren’t sure exactly how cannabinoids interact with endocannabinoid systems within the human body, they know they regulate calcium levels, blood vessel dilation, memory formation, and mood.
Cannabinoids attach themselves to specific proteins called G protein-coupled receptors throughout the body. When activated, these receptor sites trigger chemical reactions that release neurotransmitters such as dopamine, serotonin, and glutamate, which cause feelings of pleasure. Some experts say that the main active ingredient in marijuana helps to regulate sleep patterns.
Because cannabinoids target areas of the central nervous system involved in appetite regulation and energy balance, it makes sense that they would potentially improve symptoms related to obesity and metabolic syndrome, such as insulin resistance.
This theory is supported by animal studies showing that mice lacking key endocannabinoid system components were resistant to diet-induced weight gain.
Since marijuana contains natural hallucinogens, users sometimes experience visual distortions and hallucinations similar to LSD trips. In addition, although rare among experienced smokers, paranoia and panic attacks have also been linked to heavy marijuana consumption.
People who smoke too much marijuana can become short-tempered, irritable, paranoid, and aggressive. They may also think negatively about other people and events, possibly leading to suicidal thoughts. Other mental problems include impaired concentration, poor decision-making skills, and slowed cognitive function.
Now that we’ve seen what marijuana can do under normal circumstances, let’s see where depression fits. We’ll break down the case against marijuana users who suffer from severe bouts of sadness on the next page.
Recreational Use
Despite its medicinal uses, marijuana remains classified as a Schedule I substance in the U.S., meaning it has no accepted therapeutic value. Twenty-three states allow physicians to prescribe medical marijuana to alleviate patient conditions, but Florida and North Carolina are the only ones that don’t permit its distribution.
Despite legalization efforts in several states, federal law prohibits doctors from prescribing it or helping patients obtain it legally. So people hoping to self-medicate must either buy it illegally or grow their own. Nevertheless, California voters legalized recreational marijuana in November 2008, and Colorado became the latest state to pass legislation allowing residents to possess small amounts of weed for personal use.
Because marijuana remains illegal, little information exists about how well it works as a depressant. Even though marijuana is considered a highly addictive substance, many people choose to use it anyway, perhaps believing it can lift their spirits.
According to recent estimates, nearly 12 percent of adult men and 6 percent of women between 18 and 29 reported using marijuana in 2010. The reasons for doing so included relaxing after a long day, experiencing negative emotions, relieving physical discomfort, and trying to “feel something.” Another reason cited was curiosity/to try new experiences.
While marijuana certainly isn’t a cure for depression, proponents argue that it can ease the emotional distress common to depressed individuals. Many claim that it reduces stress, lowers inhibitions, and relieves tension.
Others think that marijuana dulls unpleasant memories and gives them temporary relief from fear and despair. Still, others contend that smoking marijuana can help relieve insomnia and manage chronic pain caused by illnesses such as multiple sclerosis. Cannabis enthusiasts may also use the herb to enhance sex life and induce relaxation when anxious.
Not everyone agrees, however. For example, Dr. Allen Frankel, director of behavioral sciences at Beth Israel Medical Center in New York City, told WebMD that marijuana’s sedative properties make it helpful in treating anxiety rather than depression, especially social phobia.
He notes that marijuana depresses the respiratory rate, slows the heart rate, and constricts blood vessels, contributing to dizziness and fatigue. Consequently, marijuana makes him lazy and sleepy, which he attributes to his low productivity.
Also, despite anecdotal claims, marijuana probably cannot suppress REM sleep, Frankel says. Instead, it simply induces lighter dreams, thus prolonging sleeping time. Furthermore, according to a 2009 investigation conducted by the National Academy of Sciences panel on marijuana, inhaling marijuana smoke causes bronchial swelling, chest tightness, and coughing, further worsening lung capacity.
Now we’ll explore some scientific literature on marijuana’s effectiveness as an antidepressant.
According to data collected by Gallup polls beginning in 1975, 30 percent of Americans said they’d never heard of marijuana. By 1997, however, that number jumped to 55 percent. So why did public awareness increase so quickly?
One explanation could be that marijuana became increasingly available following Prop 19, which allowed Californians to vote yes or no on legalizing commercial production and the sale of marijuana for medicinal purposes. If passed, Prop 19 would legalize marijuana sales nationwide, although it wouldn’t change existing laws prohibiting its possession or use.

Treating Depression With Weed Faqs
Studies show that marijuana improves people’s coping with everyday stresses while reducing anxiety and promoting introspection. So far, we’ve learned that marijuana possesses anti-inflammatory qualities and may help control appetite and metabolism.
As for how marijuana treats depression specifically, it’s hard to pinpoint the exact mechanism responsible, but it likely involves the part of the brain called the hippocampus, which regulates learning and memory. Since marijuana alters perception and thought processes, it stands to reason that it could influence mood and cognition, improving overall quality of life.
One study suggests that marijuana can relieve depression faster than traditional antidepressants. Published in January 2011 in JAMA Psychiatry, the results showed that, compared to SSRIs, marijuana significantly improved depression scores in patients diagnosed with moderate to moderately severe unipolar depression.
Patients took placebos instead of actual drugs for comparison. After eight weeks, participants taking marijuana scored 25% higher than those on a placebo. At week 16, those receiving marijuana saw a 26% improvement in symptoms, while subjects on placebos experienced 15% less improvement. During the second testing phase, lasting eight months, those given marijuana fared even better.
Compared to those taking placebos, they averaged 32% lower depression scores and 21% greater satisfaction with daily functioning. Of note, marijuana didn’t interfere with sexual desire or alter pain tolerance.
Another 2011 study published in the Journal of Psychopharmacology offers additional support for marijuana’s ability to act as an effective antidepressant. Participants consumed varying dosages of Tetrahydrocannabinol (the psychoactive component of marijuana) and then completed various tests designed to measure anxiety, confusion, anger, happiness, and overall contentment.
Results indicated that anxiety decreased slower than the other variables tested, lending credence to the idea that marijuana can effectively combat stress but not necessarily depression.