Initial research suggests that CBD, a natural cannabis component, might be a promising therapeutic option for reducing schizophrenia symptoms with potentially fewer side effects compared to conventional medications. More studies are needed, but CBD's favorable safety profile makes it an exciting candidate for further research.

Research about CBD

Cannabidiol (CBD) is a main natural component of cannabis plants, i.e., a substance (more precisely a cannabinoid) naturally formed by the hemp plant. Unlike other components of the hemp plant, CBD does not induce so-called altered states of consciousness or psychotic symptoms and has no known addictive potential.

In the human body, CBD acts on the body's own cannabinoid system - the endocannabinoid system - and thus supports the natural effect of the endocannabinoid system to restore the balance of various messenger molecules (called neurotransmitters such as dopamine, glutamate, and GABA) in the brain (Bisogno et al., 2001; Ryan et al., 2007, Elmes et al., 2006; Holmes et al., 2006).

Research - Evidence for CBD as an antipsychotic 

  • Excessive dopamine activity plays a key role in the manifestation of schizophrenia. CBD can help balance excessive dopamine activity in the brain. It does this by increasing levels of a natural molecule called anandamide (Leweke & Koethe, 2008). CBD stops the breakdown of anandamide, allowing more of it to stay in the body and work against excessive dopamine activity (Leweke et al., 2012, Elmes et al., 2015).

  • When anandamide levels go up, this can lead to more glucose being used in certain parts of the brain. This is important because people with schizophrenia often have issues with how the brain uses glucose, its exclusive provision of energy. In a study with rats, CBD improved glucose use in the brain (Brett et al., 2006) in a similar way to humans (Koethe et al., 2023).

  • The first landmark controlled clinical trial compared the effect of CBD with a standard antipsychotic medication (amisulpride (Leucht et al., 2002)) in people with acute schizophrenia. Both CBD and the standard medication improved symptoms similarly. However, CBD treatment caused fewer side effects, including fewer movement disorders, less weight gain, and a lower increase in the hormone prolactin (Leweke et al., 2012). Elevated prolactin levels under amisulpride can lead to breast pain, lactation, menstrual problems, and sexual dysfunction in women and headaches and loss of libido in men.

  • Although another study (McGuire et al., 2018) has also shown that CBD can help with schizophrenia, we still need more long-term data to fully understand the antipsychotic potential, i.e. the mode of action, efficacy and safety of CBD. This could also lead to the development of new treatments for schizophrenia that work through similar mechanisms to CBD.

  • The favourable safety profile (i.e., fewer side effects) and novel mechanism of action make CBD a promising therapeutic option that is being further investigated in clinical trials (Leweke et al., 2012).