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Schizophrenia – Medical Marijuana Research Overview

The following information is presented for educational purposes only. Medical Marijuana Inc. provides this information to provide an understanding of the potential applications of cannabidiol. Links to third party websites do not constitute an endorsement of these organizations by Medical Marijuana Inc. and none should be inferred.

Schizophrenia is a serious mental disorder that affects about 1% of Americans. Studies have shown cannabidiol (CBD), a cannabinoid found in cannabis, has antipsychotic properties and can thereby reduce psychotic symptoms.

Overview of Schizophrenia

Schizophrenia is a chronic and severe mental illness that interferes with the ability to think clearly, regulate emotions and connect to others. The disabling brain disorder can develop at any age, but the average age of onset is late teens to early 20s for men and late 20s to early 30s for women.

Common symptoms associated with schizophrenia include hallucinations, delusions, negative symptoms (being emotionally flat and disconnected), and disorganized thinking or cognitive issues. It can cause people to hear voices that don’t exist or may make them to believe others are reading or controlling their minds and thoughts. A person with schizophrenia may not make sense when talking or may sit for long hours without talking or moving. For a diagnosis of schizophrenia, symptoms must be present for a minimum of six months.

While the exact cause of schizophrenia remains unknown, according to the National Alliance on Mental Illness, research suggests that genetics, environment, brain chemistry and substance abuse may play a role in the disease developing. The illness occurs in 1 percent of the general population, but 10 percent of people with a first-degree relative with have the disorder develop.

There is no cure for schizophrenia, but psychotherapy and self-management strategies can help manage its symptoms. Antipsychotic medications help reduce psychotic symptoms, like hallucinations and breaks with reality.

Findings: Effects of Cannabis on Schizophrenia

While use of cannabis high in the psychoactive cannabinoid tetrahydrocannabinol (THC) has been found to be associated with an increased risk of developing psychotic disorders, numerous studies have shown that cannabidiol (CBD), a nonpsychoactive cannabinoid found in cannabis, has antipsychotic properties (Schubart, et al., 2014) (Zuardi, et al., 2012) (Robson, Guy & Di Marzo, 2014) (Roser & Haussleiter, 2012). Both animal and human subject studies have demonstrated that CBD has antipsychotic-like properties and is both safe and well tolerated (Zuardi, et al., 2006). One study found that CBD caused significantly lower degrees of psychotic symptoms (Schubart, et al., 2011). Another study found that CBD restored recognition and working memory, and social behavior to normal levels (Osborne, et al., 2017). Evidence suggests that CBD can ameliorate both positive and negative symptoms of schizophrenia (Deiana, 2013).

Researchers have suggested that cannabinoids like CBD offer antipsychotic effects because of their activation of the CB2 receptors of the endocannabinoid system. Psychotic disorders have been associated with an alteration of the immune system, which is regulated by the endocannabinoid system. Through their activation of the CB2 receptors, CBD could be helping modulate the body’s immune system and as a result, reducing psychotic symptoms (Bioque, et al., 2013). One study found that CBD inhibits the degradation of anandamide, an endocannabinoid that when elevated has been shown to be inversely correlated to psychotic symptoms and caused a significant clinical improvement (Leweke, et al., 2012).

States That Have Approved Medical Marijuana for Schizophrenia

No states have approved medical marijuana for the treatment of schizophrenia. However, in Washington D.C., any condition can be approved for medical marijuana as long as a DC-licensed physician recommends the treatment. In addition, various other states will consider allowing medical marijuana to be used for the treatment of schizophrenia with the recommendation from a physician. These states include: California (any debilitating illness where the medical use of marijuana has been recommended by a physician), Connecticut (other medical conditions may be approved by the Department of Consumer Protection), Massachusetts (other conditions as determined in writing by a qualifying patient’s physician), Nevada (other conditions subject to approval), Oregon (other conditions subject to approval), Rhode Island (other conditions subject to approval), and Washington (any “terminal or debilitating condition”).

Recent Studies on Cannabis’ Effect on Schizophrenia


Bioque, M., García-Bueno, B., MacDowell, K. S., Meseguer, A., Saiz, P. A., Parellada, M., Gonzalez-Pinto, A., Rodriguez-Jimenez, R., Lobo, A., Leza, J.C., and Bernardo, M. From the FLAMM-PEPs study—Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM). (2013). Peripheral Endocannabinoid System Dysregulation in First-Episode Psychosis. Neuropsychopharmacology, 38(13), 2568–2577. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3828529/.

Cannabis Compound May Augment Antipsychotic Meds. (2016, April 21). Medscape. Retrieved from http://www.medscape.com/viewarticle/862312#vp_2.

Deiana, S. (2013, January). Medical use of cannabis. Cannabidiol: a new light for schizophrenia? Drug Testing and Analysis, 5(1), 46-51. Retrieved from http://onlinelibrary.wiley.com/wol1/doi/10.1002/dta.1425/full.

Levin, R., Peres, F.F., Almeida, V., Calzavara, M.B., Zuardi, A.W., Hallak, J.E.C., Crippa, J.A.S., and Abilio, V.C. (2014, February 6). Effects of cannabinoid drugs on the deficit of prepulse inhibition of startle in an animal model of schizophrenia: the SHR strain. Frontiers in Pharmacology, 5, 10. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3915876/.

Leweke, F.M., Piomelli, D., Pahlisch, F., Muhl, D., Gerth, C.W., Hoyer, C., Klosterkotter, J., Hellmich, M., and Koethe, D. (2012, March 20). Cannabidiol enhances anandamide signaling and alleviates psychotic symptoms of schizophrenia. Translational Psychiatry, 2, e94. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3316151/.

Long, L.E., Malone, D.T., and Taylor, D.A. Cannabidiol reverses MK-801-induced disruption of prepulse inhibition in mice. Neuropsychopharmacology, 31(4), 795-803. Retrieved from http://www.nature.com/npp/journal/v31/n4/full/1300838a.html.

Morgan, C.J.A., and Curran, H.V. (2008). Effects of cannabidiol on schizophrenia-like symptoms in people who use cannabis. The British Journal of Psychiatry, 192, 306-307. Retrieved from http://bjp.rcpsych.org/content/192/4/306.long.

Osborne, A.L., Solowij, N., Babic, I., Huang, X.F., and Weston-Green, K. (2017, June). Improved Social Interaction, Recognition and Working Memory with Cannabidiol Treatment in a Prenatal Infection (poly I:C) Rat Model. Neuropsychopharmacology, (42(7), 1447-1457. Retrieved from https://www.nature.com/npp/journal/v42/n7/full/npp201740a.html.

Robson, P.J., Guy, G.W., and Di Marzo, V. (2014). Cannabinoids and schizophrenia: therapeutic prospects. Current Pharmaceutical Design, 20(13), 2194-204. Retrieved from http://www.eurekaselect.com/111821/article.

Roser, P., and Haussleiter, I.S. (2012). Antipsychotic-like effects of cannabidiol and rimonabant: systematic review of animal and human studies. Current Pharmaceutical Design, 18(32), 5141-55. Retrieved from http://www.eurekaselect.com/102850/article.

Sarrazin, S., Louppe, F., Doukhan, R., & Schürhoff, F. (2015). A clinical comparison of schizophrenia with and without pre-onset cannabis use disorder: a retrospective cohort study using categorical and dimensional approaches. Annals of General Psychiatry, 14, 44. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4676097/.

Schizophrenia. (n.d.) National Institute of Mental Health. Retrieved from http://www.nimh.nih.gov/health/topics/schizophrenia/index.shtml#part_145430.

Schizophrenia. (n.d.). National Alliance on Mental Illness. Retrieved from https://www.nami.org/Learn-More/Mental-Health-Conditions/Schizophrenia.

Schubart, C.D., Sommer, I.E., Fusar-Poli, P., de Witte, L., Kahn, R.S., and Boks, M.P. (2014, January). Cannabidiol as a potential treatment of psychosis. European Neuropsychopharmacology, 24(1), 41-64. Retrieved from http://www.europeanneuropsychopharmacology.com/article/S0924-977X(13)00332-5/fulltext.

Schubart, C.D., Sommer, I.E., van Gastel, W.A., Goetgebuer, R.L., Kahn, R.S., and Boks, M.P. (2011, August). Cannabis with high cannabidiol content is associated with fewer psychotic experiences. Schizophrenic Research, 130(1-3), 216-21. Retrieved from http://www.schres-journal.com/article/S0920-9964(11)00224-6/fulltext.

Zuardi, A.W., Crippa, J.A., Hallak, J.E., Moreira, F.A., and Guimaraes, F.S. (2006, April). Cannabidiol, a cannabis sativa constituent, as an antipsychotic drug. Brazilian Journal of Medical and Biological Research, 39(4), 421-9. Retrieved from http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000400001&lng=en&nrm=iso&tlng=en.

Zuardi, A.W., Crippa, J.A., Hallak, J.E., Bhattacharyya, S., Atakan, Z., Martin-Santos, R., McGuire, P.K., and Guimaraes, F.S. (2012). A critical review of the antipsychotic effects of cannabidiol: 30 years of translational investigation. Current Pharmaceutical Design, 18(32), 5131-40. Retrieved from http://www.eurekaselect.com/102849/article.

  • December 11, 2015
  • Eve Ripley