There is much anecdotal evidence from people with bipolar disorder to suggest that using cannabis is beneficial for symptoms of this condition. However, scientists are not so sure.

Certain studies show that cannabis can worsen bipolar disorder symptoms. However, other research suggests cannabis can improve some symptoms of bipolar, such as those related to attention and memory, while negatively affecting others. For example, cannabis has associations with higher levels of manic and depressive episodes.

This article discusses research on cannabis as a treatment for bipolar disorder. It also explores other medical uses for cannabis and alternative approaches for managing bipolar disorder.

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Bipolar disorder is a mental health condition. According to the National Institute of Mental Health, it causes shifts in:

  • mood
  • energy
  • activity levels
  • the ability to carry out everyday tasks

People with bipolar disorder can have manic episodes where they feel elated and energized for periods. They may also have depressive episodes where they feel sad, indifferent, or hopeless. The shift between the two can be extreme.

People with the condition may also experience delusions and hallucinations.

The exact cause of the condition is unknown, although it appears to stem from a combination of environmental, biological, and genetic factors.

Many people with bipolar disorder use cannabis to help manage and treat their symptoms. Anecdotally, many reports claim the substance is beneficial, although the scientific evidence remains unclear.

The cannabis plant comprises more than 480 chemical compounds. These include delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), which are the most well-known of these cannabinoids.

THC is responsible for the “high” that many people associate with cannabis use, whereas CBD is gaining popularity as an alternative treatment for numerous conditions, including some mental health issues.

People should note that many studies investigating the effect of cannabis on bipolar disorder have focused on the use of THC.

Negative effects

There have been numerous studies on the link between bipolar disorder and cannabis. Some of these studies feature in a 2017 review from the Alcohol and Drug Abuse Institute (ADAI).

The report found a link between cannabis use and the following health issues:

  • development of bipolar at an earlier age
  • longer or worse manic episodes
  • higher likelihood of suicide attempts
  • rapid cycling or quickly shifting from manic to depressive episodes
  • suicidal ideation in people who were heavy users of THC

A 2021 review of research investigated the link between substance use disorder (SUD) and bipolar disorder. One substance a person with SUD may misuse is cannabis. The researchers found that SUD may lead to:

  • development of more severe bipolar disorder
  • more frequent hospitalizations
  • more frequent relapses
  • higher rates of violence and suicide

Additionally, a 2018 review of research explored a range of studies, some of which found that people with bipolar disorder who used cannabis were less likely to go into remission for their condition than those who did not.

Positive effects

Not all the studies into the effects of cannabis on bipolar disorder have been negative. A small 2016 pilot study asked people with the condition to rate their feelings after using the substance. Within 4 hours of using the drug, people reported the following:

  • less anger
  • less tension
  • less depression
  • higher energy levels

Additionally, an older study from 2010, which looked at 133 people with the condition, stated that the participants who used cannabis showed improvements in:

  • reasoning speed
  • attention
  • memory


However, both the ADAI report and the 2018 research review concluded that there was more evidence of negative effects of cannabis on bipolar disorder than positive ones.

The risks of cannabis use include:

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

  • Ask the tough question: “Are you considering suicide?”
  • Listen to the person without judgment.
  • Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
  • Stay with the person until professional help arrives.
  • Try to remove any weapons, medications, or other potentially harmful objects if it’s safe to do so.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The 988 Suicide and Crisis Lifeline is available 24 hours a day at 988. During a crisis, people who are hard of hearing can use their preferred relay service or dial 711 then 988.

Find more links and local resources.

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Many U.S. states have legalized cannabis for medical use. Some doctors recommend the substance to treat mental health conditions such as:

However, the patient advocacy group Mental Health America warns that the evidence supporting this recommendation mainly comes from anecdotal reports and animal studies. Therefore, researchers need to conduct more studies before drawing firm conclusions about the effects of cannabis use.

Scientists have been studying the effects of cannabis on health conditions for a long time.

According to the National Institute on Drug Abuse, THC does have medical benefits when used in certain medicines.

For example, healthcare professionals use dronabinol (Marinol) and nabilone (Cesamet) to treat nausea in people who undergo chemotherapy. These same drugs can stimulate appetite in those with wasting syndromes related to AIDS.

In Canada, the United Kingdom, and some European countries, doctors can prescribe nabiximols (Sativex). It is a mouth spray containing THC and CBD, which can help people with the symptoms of multiple sclerosis.

In the United States, doctors can recommend a CBD-based liquid medication called Epidiolex for two forms of severe childhood epilepsy: Dravet syndrome and Lennox-Gastaut syndrome.

Recently, scientists have investigated whether CBD can help with bipolar disorder.

CBD is usually an oil that manufacturers and pharmaceutical companies extract from the cannabis plant. Depending on the growing method and extraction process, CBD products may contain varying amounts of THC.

Currently, health experts cannot confirm if CBD helps those with bipolar disorder. For example, a small 2020 study found that some participants’ bipolar symptoms improved after using the substance. However, other individuals saw no difference.

Researchers need to conduct more studies before they can conclude that CBD is safe and can help those with bipolar disorder.

Is CBD legal?The 2018 Farm Bill removed hemp from the legal definition of marijuana in the Controlled Substances Act. This made some hemp-derived CBD products with less than 0.3% THC federally legal. However, CBD products containing more than 0.3% THC still fall under the legal definition of marijuana, making them federally illegal but legal under some state laws. Be sure to check state laws, especially when traveling. Also, keep in mind that the FDA has not approved nonprescription CBD products, and some products may be inaccurately labeled.

Many supplements and remedies claim to help people manage the symptoms of bipolar disorder. However, scientists have found limited evidence to support them, so most people with the condition need to take medication.

Despite this, there are many ways for individuals to ease their symptoms. A person can monitor their symptoms to learn the triggers that can worsen them.

Factors that can exacerbate bipolar disorder symptoms are different for everyone, but they may include stress, seasonal changes, or a lack of sleep. These are things that people may be able to manage with natural remedies and certain behaviors, such as maintaining an active, healthy daily routine.

People with bipolar disorder may wish to try the following:

  • sticking to a strict daily schedule with set times for eating, socializing, working, and relaxing
  • getting regular exercise
  • keeping to a strict sleep schedule
  • eating a healthy and balanced diet

It is also vital that people continue to take their medications — do not stop or skip doses unless advised to do so by a healthcare professional.

Many people with bipolar disorder use cannabis to treat their symptoms. There is plenty of anecdotal evidence to support its use.

However, while there is little scientific evidence to support the efficacy of cannabis in treating bipolar disorder, some studies conclude the substance may, in fact, worsen symptoms.

Some people also use cannabis to treat other mental health disorders, but there is limited evidence of its effectiveness.

Individuals should consult with a doctor before using cannabis to treat bipolar disorder, as there are some potential risks associated with the drug.