How does cannabis affect bipolar disorder?

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A few days ago, one of the newspapers with the greatest impact in Spain published an article entitled “Cannabis can trigger bipolar disorder“, in which Dr. Eduard Vieta, head of psychiatry at Hospital Clínic, warns about the risks of cannabis consumption. The headline’s statement has generated impact, especially among those seeking alternatives within the world of cannabis, such as CBD.

Bipolar disorder is a mental health condition characterized by extreme mood swings, ranging from episodes of euphoria to periods of deep depression. Given the growing popularity of cannabidiol (CBD) and the medical and recreational use of marijuana, many people with bipolar disorder are wondering how these cannabinoids might affect them. Here’s an overview of the scientific research on the relationship between CBD and THC use in bipolar disorder, highlighting potential risks and areas of uncertainty.

What is bipolar disorder?

Bipolar disorder is a complex psychiatric condition that causes abrupt mood swings that can interfere with work, relationships and daily activities. There are two main types:

Bipolar I disorder: characterized by at least one episode of mania, usually accompanied by depressive episodes.
Bipolar II disorder: characterized by recurrent depressive episodes and hypomanic episodes (a less severe form of mania).

Approximately 2.4% of the world’s population lives with this condition (1). Treatment usually includes mood stabilizers (such as lithium or valproate), antipsychotics and psychosocial therapy.

Any substance that affects the brain, including marijuana, can complicate treatment and potentially aggravate the symptoms of bipolar disorder.

How does cannabis act in the brain?

Cannabis contains numerous cannabinoids, the best known being THC (tetrahydrocannabinol) and CBD (cannabidiol). THC produces the “high” or psychoactive effect, while other cannabinoids, such as CBD, have minor or no psychoactive effects.

Vapear H4CBD HHC THC — Frequent THC use in young people may increase risk of altered brain chemistry

Because cannabinoids such as THC have their effects on the brain, it is important to note that the younger the person who uses marijuana frequently or heavily, the greater their vulnerability to experiencing alterations in brain chemistry may be (2). This is due, in large part, to the effects of THC on the brain.

Tetrahydrocannabinol (THC) is the main psychoactive compound in marijuana. THC acts on the endocannabinoid system, which plays a key role in regulating mood, sleep and stress response. However, frequent use can disrupt this balance, especially in young people whose brains are still developing.

The THC content of marijuana has increased significantly in recent decades, rising from approximately 4% to as much as 35% THC in less than 30 years. This increase in the potency of cannabis amplifies the risks associated with its use today.

There are now THC-free cannabis strains, CBD, with a THC content of less than 0.2%. In fact, some people use CBD to quit joints.

Cannabis use in bipolar disorder

Several studies show that people with bipolar disorder may use cannabis more frequently than the general population. Reasons for this tendency include self-medication to mitigate symptoms of anxiety or insomnia, the coexistence of other substance use disorders, and certain genetic or environmental predispositions (3).

Although some people claim that cannabis relieves anxiety or depressive symptoms, scientific evidence on its efficacy remains limited and sometimes contradictory.

Potential risks of marijuana use in bipolar disorder.

One of the most consistent findings in the literature is that marijuana use can worsen manic or hypomanic symptoms (3). Not everyone reacts the same, but frequent or heavy use has been linked to a greater likelihood of prolonging or triggering manic episodes, increasing impulsivity, and promoting risky behaviors (2).

Although it has been observed that marijuana may aggravate mania, some people report short-term relief of their depressive symptoms. However, these experiences are largely subjective and are not supported by conclusive clinical studies. In addition, self-medication with marijuana in bipolar disorder can be dangerous, and a mental health professional should always be consulted.

Does marijuana use cause bipolar disorder?

So far, marijuana use has not been proven to be the direct cause of bipolar disorder. However, in people predisposed to mood disorders, frequent marijuana use may trigger the first bipolar episode. A scientific review indicates that regular marijuana users are more likely to develop bipolar disorder for the first time, suggesting that marijuana may act as a trigger in vulnerable individuals (2). In addition, heavy and prolonged marijuana use has been associated with an increased risk of psychosis in individuals who are prone to develop such symptoms (4), although not all people with bipolar disorder who use marijuana will develop psychosis.

Does CBD cause bipolar disorder?

No, there is no scientific evidence that CBD causes bipolar disorder. In fact, some studies suggest that it may have potential benefits, although its use in bipolar disorder still requires more research.

CBD in bipolar disorder

Unlike THC, CBD is non-psychoactive and has attracted medical research interest for its potential anxiolytic, anti-inflammatory and neuroprotective properties. Some preliminary studies suggest that high doses of CBD may help treat depressive symptoms in bipolar disorder. In addition, its potential antipsychotic effect has been investigated in diseases such as schizophrenia.

While there is no evidence that CBD worsens bipolar disorder, studies are still limited, and more clinical trials are needed to determine its effectiveness and safety as part of treatment.

Details: Scientific Studies on CBD and Bipolar Disorder

Preliminary studies suggest that CBD may have anxiolytic, anti-inflammatory and neuroprotective effects. However, scientific evidence on its direct efficacy in bipolar disorder is limited (5). Some researchers have raised the possibility that high doses of CBD (more than 300 mg per day) may help in bipolar depression, but clinical trials that solidly confirm this are lacking (6).

CBD has also been studied for its possible antipsychotic properties in schizophrenia (7), a disorder that sometimes shares features with bipolar mania. Although these findings are not directly applicable to bipolar disorder, they suggest that CBD may have some utility in controlling psychotic symptoms in manic episodes. Despite this, no clear negative effects of CBD in bipolar disorder have been described, although definitive data are still lacking.

Clinical implications of cannabis in bipolar disorder

Health professionals should routinely ask about cannabis use in people with bipolar disorder, as it could affect the course of the illness. Likewise, both patients and their families should be aware of the risks associated with the use of psychoactive substances such as marijuana, especially because of its relationship with manic relapses and cognitive impairment.

Although it has been suggested that CBD may be useful as an adjunctive treatment for bipolar depression (6), more research is needed. In the meantime, it is critical that people with bipolar disorder avoid self-medication without medical supervision, as it may unbalance mood and complicate established treatment.

Conclusion

Scientific evidence indicates that marijuana use may present risks for those with bipolar disorder, including increased risk of manic episodes, possible impairment of cognitive function, and treatment complications. Although some users report temporary relief from depression, these data do not have strong clinical support. In the specific case of CBD, larger clinical trials are required to accurately determine its benefits and risks in this disorder.

Note: This is an informative article with no prescriptive character, it is not intended to prevent, diagnose or treat any disease. Its content can complement, but should never replace, the diagnosis or treatment of any disease or symptom. If you or someone close to you is experiencing symptoms of bipolar disorder or are considering changes in your treatment (including the use of cannabis), consult with a health care professional. Cannactiva products are not medicines and are intended for external use. There may be new relevant scientific evidence since the date of publication. Consult with your physician before using CBD. Therapeutic advice should be personalized and depends on professional assessment.

References and further information

Zhong, Y., Chen, Y., Su, X., Wang, M., Li, Q., Shao, Z., & Sun, L. (2024). Global, regional and national burdens of bipolar disorders in adolescents and young adults: a trend analysis from 1990 to 2019. General psychiatry, 37(1), e101255 . https://doi.org/10.1136/gpsych-2023-101255.
Maggu, G., Choudhary, S., Jaishy, R., Chaudhury, S., Saldanha, D., & Borasi, M. (2023). Cannabis use and its relationship with bipolar disorder: A systematic review and meta-analysis. Industrial psychiatry journal, 32(2), 202-214 . https://doi.org/10.4103/ipj.ipj_43_23.
Lev-Ran, S., Le Foll, B., McKenzie, K., George, T. P., & Rehm, J. (2013). Bipolar disorder and co-occurring cannabis use disorders: characteristics, co-morbidities and clinical correlates. Psychiatry research, 209(3), 459-465. https://doi.org/10.1016/j.psychres.2012.12.014
Di Forti, M., Quattrone, D., Freeman, T. P., Tripoli, G., Gayer-Anderson, C., Quigley, H., Rodriguez, V., Jongsma, H. E., Ferraro, L., La Cascia, C., La Barbera, D., Tarricone, I., Berardi, D., Szöke, A., Arango, C., Tortelli, A., Velthorst, E., Bernardo, M., Del-Ben, C. M., Menezes, P. R., … EU-GEI WP2 Group (2019). The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case-control study. The lancet. Psychiatry, 6(5), 427-436. https://doi.org/10.1016/S2215-0366(19)30048-3
Khan, R., Naveed, S., Mian, N., Fida, A., Raafey, M. A., & Aedma, K. K. (2020). The therapeutic role of Cannabidiol in mental health: a systematic review. Journal of cannabis research, 2(1), 2. https://doi. org/10.1186/s42238-019-0012-y
Pinto, J. V., Crippa, J. A. S., Ceresér, K. M., Vianna-Sulzbach, M. F., Silveira Júnior, É. M., Santana da Rosa, G., Testa da Silva, M. G., Hizo, G. H., Simão Medeiros, L., Santana de Oliveira, C. E., Bristot, G., Campos, A. C., Guimarães, F. S., Hallak, J. E. C., Zuardi, A. W., Yatham, L. N., Kapczinski, F., & Kauer-Sant’Anna, M. (2024). Cannabidiol as an Adjunctive Treatment for Acute Bipolar Depression: A Pilot Study: Le cannabidiol comme traitement d’appointment de la dépression bipolaire aiguë : une étude pilote. Canadian journal of psychiatry. Canadian Journal of Psychiatry, 69(4), 242-251 . https://doi.org/10.1177/07067437231209650.
Leweke, F. M., Piomelli, D., Pahlisch, F., Muhl, D., Gerth, C. W., Hoyer, C., Klosterkötter, J., Hellmich, M., & Koethe, D. (2012). Cannabidiol enhances anandamide signaling and alleviates psychotic symptoms of schizophrenia. Translational psychiatry, 2(3), e94. https://doi.org/10.1038/tp.2012.15