Understanding the Potential Benefits of Cannabidiol for Patients With Schizophrenia: A Narrative Review

Abstract

Research suggests that cannabis-derived delta-9- tetrahydrocannabinol (THC) can be linked to the worsening of psychosis and/or other symptoms of schizophrenia. However, studies have shown that another major cannabinoid found in cannabis, cannabidiol (CBD), may be a potential alternative or adjunctive treatment for psychosis and schizophrenia. As such, herein we review the relevant literature relating to the safety and efficacy of CBD treatment in patients with schizophrenia, including the effects of CBD in treating the positive, negative, and cognitive symptoms of the disorder, as well as the molecular mechanisms by which CBD can reduce schizophrenic symptoms. The potential utility of CBD for mitigating cannabis cravings and cannabis withdrawal in this patient population will also be reviewed. Lastly, the dosing, method of drug delivery, length of treatment, and adverse effects of CBD in patients with schizophrenia are also discussed. Thus, the goal of this narrative review is to help clinicians and researchers better understand the risks and benefits of this potential therapy for this patient population.

Modulation of neuroinflammation and oxidative stress by targeting GPR55 – new approaches in the treatment of psychiatric disorders

“…For schizophrenia, some authors suggest potential antipsychotic effects of CBD via inhibition of GPR55 [81]. Since more than 65 molecular targets of CBD are known [82], these observed effects of CBD might only partially depend on GPR55.…”

Easy as CBD: A cannabidiol primer for mental health professionals.

“…Although several animal studies support CBD as an antipsychotic alternative, only a handful of human studies exist; often focus on neuroimaging, rather than behavioral outcomes; and research is mixed (Davies & Bhattacharyya, 2019; Dyck et al, 2022). CBD did not mitigate cognitive deficits in a rigorous randomized clinical trial with outpatients diagnosed with schizophrenia as it has with rodents (Boggs et al, 2018).…”

Differential effects of cannabis constituents on schizophrenia-related psychosis: a rationale for incorporating cannabidiol into a schizophrenia therapeutic regimen

“…The authors concluded there was insufficient evidence to recommend medical cannabis to treat schizophrenia ( 26 ). However, the notion continues to gain traction, with several ongoing clinical trials ( 27 – 29 ). Here, we compare the etiopathophysiology underlying schizophrenia- vs. cannabis-related psychoses and revisit the rationale for adding CBD to conventional schizophrenia treatment regimens.…”

“…Along with antipsychotic effects, CBD anecdotally decreases symptoms of neuroleptic-induced parkinsonism and exerts anxiolytic and anticonvulsive actions (22)(23)(24)(25). A systematic review by Ahmed et al examined the effects of delta-9-THC and CBD on schizophrenia symptoms from eleven clinical trials conducted from 2005-2021 (26). The authors concluded there was insufficient evidence to recommend medical cannabis to treat schizophrenia (26).…”

“…A systematic review by Ahmed et al examined the effects of delta-9-THC and CBD on schizophrenia symptoms from eleven clinical trials conducted from 2005-2021 (26). The authors concluded there was insufficient evidence to recommend medical cannabis to treat schizophrenia (26). However, the notion continues to gain traction, with several ongoing clinical trials (27)(28)(29).…”