Is Marijuana a Depressant?

Marijuana is a psychoactive drug that can act as a depressant for some people and as a stimulant for others. Learn more about marijuana's short- and long-term effects.

Marijuana as a Depressant

Despite decades of research on marijuana's effects, researchers still don't fully understand exactly how it works. Marijuana can have a depressant effect, but it’s not technically or chemically a depressant. Some people might experience depressant effects while using marijuana, whereas others might not.

The strain of marijuana also plays a role. Some strains are energizing; others are more sedating.

Marijuana Use for Mental Health Conditions

It bears repeating that research on the use of marijuana for mental health is in its very early stages. Therefore, whether this drug is effective or safe to use for certain mental health disorders is still unclear.

For example, a possible link between depression and marijuana is often discussed, whether as a cause or a treatment, but there's no evidence to back either claim. Some research does indicate that the depressant effects of marijuana might worsen depression symptoms in some people.

As for safety, studies show that combining marijuana with other drugs (whether prescribed, over the counter, or illicit) can be harmful, These include warfarin, clobazam, and central nervous system depressants such as alcohol, barbiturates, and benzodiazepines.

Effects of Marijuana Use

The most common short-term effects of marijuana use include: 

• Altered senses, i.e., seeing colors more vividly or hearing music more loudly
• Difficulty thinking
• Feeling an altered sense of time
• Memory impairment 
• Mood swings 

When smoked, the effects of marijuana are more immediate than when ingested. In the latter case, effects can take several minutes to hours to appear because the drug must pass through the digestive system first. Marijuana's effects also last longer when ingested.

Research is just beginning to uncover associations between brain health and long-term cannabis use. In a 2014 study, researchers found that marijuana use could affect neural connectivity in parts of the brain that carry out memory and learning functions. A 2022 study found that long-term use is connected to cognitive deficits and decreased hippocampal volume in midlife.

Can Marijuana Be a Stimulant or Hallucinogen?

In addition to having depressant effects, marijuana can act as a stimulant or hallucinogen, depending on method, strain, and amount. 

Stimulant Effects

Stimulants are psychoactive drugs that increase brain activity, similar to what one would experience while in a manic state. They cause a disruption in the normal communication which typically occurs in the brain's neurons and circuits.

Marijuana sometimes has stimulant effects and research has found that the more a person anticipates these effects, the heavier and more frequent their marijuana use. This type of use can potentially lead to marijuana dependency and addiction. 

Stimulants are also associated with side effects such as increased anxiety, nausea, tremors, and seizures. 

Hallucinogenic Effects

Hallucinogens are drugs that are capable of altering your view of reality. For example, when using a hallucinogen, a person might hear or see things that aren’t there. Although rare, marijuana can cause mild hallucinogenic effects.