Does Cannabis Use Affect Bipolar Disorder Symptoms?

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 disorder.

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 study 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 investigation 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.

Evidence suggests cannabis use may have a negative impact on symptoms of bipolar disorder.

Many researchers suggest that people with bipolar disorder should exercise caution when considering using cannabis either for recreational or medicinal purposes.

In 2017, a review from the Alcohol and Drug Abuse Institute examined related studies and reported that cannabis use for bipolar disorder was often linked to:

• increased likelihood of symptoms of psychosis, such as hallucinations and delusions
• increase in the frequency of mood episodes, with the average being four episodes in 1 year
• increased likelihood of suicidal thoughts or attempts
• more severe symptoms during episodes of mania or depression
• decreased chances of a long term-remission
• increased likelihood of experiencing challenges in task performance
• earlier onset of symptoms of bipolar disorder

Symptoms of psychosis refer to altered perceptions or thoughts. Examples are hallucinations and delusions.

In some cases, cannabis use has been associated with higher chances of experiencing these symptoms in the general population.

A 2019 study, for example, found that daily use of cannabis was linked to a higher chance of psychotic disorder.

Results also indicated that people who used high-potency cannabis (concentrations of 10% THC or more) were up to six times more likely to experience symptoms of psychosis.

Older related research has also suggested that cannabis use is associated with a greater rate of psychosis in people living with bipolar disorder as well as more frequent hospitalizations and longer mood episodes.

A 2021 study also suggests that cannabis use, particularly among young adults living with bipolar disorder and other mood disorders, may lead to a higher chance of:

• self-harm
• psychiatric hospitalizations
• mental health emergency visits

A 2010 study found that people who had both cannabis use disorder and bipolar disorder also presented with:

• higher levels of disability
• higher rates of symptoms of psychosis
• more frequent manic and depressive episodes

Cannabis use has been linked to many health effects in the general population.

Some ways cannabis use may affect your body and brain include:

• increased chance of heart disease (when smoked)
• memory impairment
• increased challenges in attention, coordination, and reflexes
• chances of experiencing anxiety, depression, and paranoia

If you live with bipolar disorder, many treatment options are still available to you.

Traditional bipolar treatment includes the use of medications, talk therapy, and self-help methods.

Common prescriptions may include:

• mood stabilizers
• antipsychotics
• anticonvulsants
• antidepressants

Talk therapy may include:

• psychoeducation
• cognitive behavioral therapy
• family-focused therapy
• interpersonal and social rhythm therapy
• dialectical behavioral therapy

Self-care strategies for bipolar disorder may include:

• mood tracking and journaling
• establishing daily routines
• sticking to treatment plans, even when feeling better
• creating a safety plan for a crisis situation
• support groups
• stress-relief activities

As a natural option, cannabis for bipolar disorder treatment may be appealing to you at first.

However, while there’s limited evidence of cannabis having some benefits for people with bipolar disorder, most studies on the topic point to inconclusive results or indications that the risks outweigh those benefits.

Cannabis use for mental health conditions is an emerging area of study. More information is needed to establish guidelines.

In the case of bipolar disorder, existing evidence suggests severe side effects of cannabis use, including symptoms of psychosis in some instances.

If you’ve received a diagnosis of bipolar disorder or are exploring alternative treatment options, consider talking with a health professional who specializes in bipolar disorder.

These resources can help you get started:

• American Psychiatric Association’s Find a Psychiatrist tool
• American Psychological Association’s Find a Psychologist tool
• National Alliance on Mental Illness Helplines and Support Tools
• National Institute of Mental Health’s Helpline Directory