After all, cannabis is natural and could be an appealing alternative to some of the usual bipolar disorder medications and their side effects.

But is cannabis actually effective in managing symptoms of bipolar disorder? Or could it make it worse?

Research is inconclusive so far. Most of the available information on bipolar disorder and cannabis use is anecdotal.

In general, cannabis use for bipolar disorder is associated with the development of more severe symptoms and lower compliance to traditional treatments. A few benefits have been suggested from small-scale studies.

Cannabis is a plant that’s been used both recreationally and medicinally.

The cannabis plant contains more than 500 chemical compounds known as cannabinoids. The most known compounds are cannabidiol (CBD) and delta-9 tetrahydrocannabinol (THC).

Although both CBD and THC affect brain function, THC is the major psychoactive agent present in cannabis.

What many people call cannabis actually refers to the products made from parts of the plant with the highest concentrations of THC. For example, the flowers. This is what we refer to as smoked cannabis.

CBD is often extracted from the stems and leaves of some types of cannabis plants. It’s been used as a therapeutic oil and as an ingredient in other products, such as gummies and lotions. It contains little to no THC.

You may or may not have used cannabis before or have an idea of what effects cannabis has on your mood.

A 2019 research review, published in Neuroscience and Biobehavioral Reviews, found that as many as 24% of people living with bipolar disorder use cannabis or have experienced cannabis use disorderTrusted Source.

The effects of cannabis use in people with bipolar disorder aren’t clear because of the absence of controlled clinical trials and some contradictory evidence.

In other words, whether cannabis has true medicinal benefits for symptoms of bipolar disorder is still under research.

Most of the evidence on cannabis use for bipolar disorder comes from personal testimonials, otherwise known as anecdotal reports, though a few smaller studies on its impact do exist.

The limited data suggests cannabis may have some positive effects on some people with bipolar disorder by offering:

• relief of varying symptoms
• a positive influence on daily outlook
• short-term relief of symptoms
• no cognitive impairment

Relief of varying symptoms

The effects of THC in the body may depend on many factors, such as dose, frequency, personality, and how you take it — smoked or ingested, for example.

This is why for some people, smoked cannabis may bring on some euphoria and excitation, while for some others, the effects include relaxation and sedation.

For example, a 2005 research review indicated that THC could reduce anxiety symptoms in some doses but could have the opposite effect in higher doses.

The same review indicated other pharmacological properties of THC that could be therapeutic for some people with bipolar disorder, such as:

• improvement in mood
• antidepressant effects
• hypnotic effects
• low toxicity

Older anecdotal information also suggests that some people find smoking cannabis beneficial for treating some of their bipolar symptoms. Specifically, this report from 1998 — based on limited case studies — found these effects:

• relief of prescription medication side effects
• relief of manic symptoms, including rage
• decreased need for medications
• improvement in depressive symptoms

Positive affect

A 2015 studyTrusted Source suggests cannabis use is associated with more positive emotions in some people with bipolar disorder.

The results of the study have a few limitations, though. For one, the study sample consisted of only 24 participants.

Also, those participants who experienced subsequent positive affect after using cannabis were already feeling well and not experiencing severe bipolar symptoms at the moment.

Short-term relief of symptoms

In 2016, PLOS One published a pilot investigationTrusted Source that explored the effects of cannabis use on mood and neuropsychological performance of people living with bipolar disorder.

The preliminary evidence suggested that people with bipolar disorder who also smoked cannabis experienced relief of some of their symptoms within 4 hours.

Specifically, smoking cannabis was associated with a decreased experience in emotions such as:

• anger
• depression
• tension or stress

Higher levels of vigor were also reported after cannabis use among people living with bipolar disorder.

Also, researchers did not find any additional cognitive deficits or impairment among cannabis smokers compared with nonsmokers who also have bipolar disorder.

No cognitive impairment

Along the same lines, a 2020 research review, published in Psychiatry Research, didn’t find any conclusive evidence regarding the effects of cannabis use on the cognitive function of people with bipolar disorder.

Of the six studies reviewed, most indicated cannabis use with bipolar disorder wasn’t directly linked to significant cognitive impairment. Among those six studies, one did suggest cannabis use was associated with worse overall cognition.

However, the authors noted that the scope of knowledge in this field is still limited, and additional research is needed.