OBJECTIVES: Understanding whether cannabidiol (CBD) is useful and safe for the treatment of psychiatric disorders is essential to empower psychiatrists and patients to take good clinical decisions. Our aim was to conduct a systematic review regarding the benefits and adverse events (AEs) of CBD in the treatment of schizophrenia, psychotic disorders, anxiety disorders, depression, bipolar disorder and substance-use disorders. METHODS: We conducted a literature search in PubMed, Scielo, and Clinicaltrials.gov databases. Evidence was classified according to the WFSBP task forces standards. RESULTS: Bibliographic research yielded 692 records. After analysis, we included six case reports and seven trials, comprising 201 subjects. Most the studies published presented several drawbacks and did not reach statistical significance. We have not found evidence regarding major depressive and bipolar disorders. The level of evidence for cannabis withdrawal is B; cannabis addiction is C2; treatment of positive symptoms in schizophrenia and anxiety in social anxiety disorder is C1. Discrete or no AEs were reported. The most frequently reported AEs are sedation and dizziness. CONCLUSIONS: The evidence regarding efficacy and safety of CBD in psychiatry is still scarce. Further larger well-designed randomised controlled trials are required to assess the effects of CBD in psychiatric disorders. (PsycInfo Database Record (c) 2021 APA, all rights reserved)
BACKGROUND AND OBJECTIVES: Cognitive impairment is a core symptom domain of schizophrenia, neurological disorders and substance abuse. It is characterised by deficits in learning, memory, attention and executive functioning and can severely impact daily living. Antipsychotic drugs prescribed to treat schizophrenia provide limited cognitive benefits and novel therapeutic targets are required. Cannabidiol (CBD), a component of the cannabis plant, has anti-inflammatory and antipsychotic-like properties; however, its ability to improve cognitive impairment has not been thoroughly explored. The aim of this systematic review was to evaluate preclinical and clinical literature on the effects of CBD in cognitive domains relevant to schizophrenia.
METHODS: A systematic literature search was performed across numerous electronic databases for English language articles (January 1990 to March 2016), with 27 articles (18 preclinical and 9 clinical studies) included in the present review.
RESULTS: CBD improves cognition in multiple preclinical models of cognitive impairment, including models of neuropsychiatric (schizophrenia), neurodegenerative (Alzheimer's disease), neuro-inflammatory (meningitis, sepsis and cerebral malaria) and neurological disorders (hepatic encephalopathy and brain ischemia). To-date, there is one clinical investigation into the effects of CBD on cognition in schizophrenia patients, with negative results for the stroop test. CBD attenuates Δ(9)-THC-induced cognitive deficits.
CONCLUSIONS: The efficacy of CBD to improve cognition in schizophrenia cannot be elucidated due to lack of clinical evidence; however, given the ability of CBD to restore cognition in multiple studies of impairment, further investigation into its efficacy in schizophrenia is warranted. Potential mechanisms underlying the efficacy of CBD to improve cognition are discussed.
Importance: Cannabis and cannabinoid drugs are widely used to treat disease or alleviate symptoms, but their efficacy for specific indications is not clear. OBJECTIVE: To conduct a systematic review of the benefits and adverse events (AEs) of cannabinoids. Data sources: Twenty-eight databases from inception to April 2015. Study selection: Randomized clinical trials of cannabinoids for the following indications: nausea and vomiting due to chemotherapy, appetite stimulation in HIV/AIDS, chronic pain, spasticity due to multiple sclerosis or paraplegia, depression, anxiety disorder, sleep disorder, psychosis, glaucoma, or Tourette syndrome. Data extraction and systemsis: Study quality was assessed using the Cochrane risk of bias tool. All review stages were conducted independently by 2 reviewers. Where possible, data were pooled using random-effects meta-analysis. Main outcomes and measures: Patient-relevant/disease-specific outcomes, activities of daily living, quality of life, global impression of change, and AEs. RESULTS: A total of 79 trials (6462 participants) were included; 4 were judged at low risk of bias. Most trials showed improvement in symptoms associated with cannabinoids but these associations did not reach statistical significance in all trials. Compared with placebo, cannabinoids were associated with a greater average number of patients showing a complete nausea and vomiting response (47%vs 20%; odds ratio [OR], 3.82 [95%CI, 1.55-9.42]; 3 trials), reduction in pain (37%vs 31%; OR, 1.41 [95%CI, 0.99-2.00]; 8 trials), a greater average reduction in numerical rating scale pain assessment (on a 0-10-point scale; weighted mean difference [WMD], −0.46 [95%CI, −0.80 to −0.11]; 6 trials), and average reduction in the Ashworth spasticity scale (WMD, −0.36 [95%CI, −0.69 to −0.05]; 7 trials). There was an increased risk of short-term AEs with cannabinoids, including serious AEs. Common AEs included dizziness, dry mouth, nausea, fatigue, somnolence, euphoria, vomiting, disorientation, drowsiness, confusion, loss of balance, and hallucination. Conclusions and relevance: There was moderate-quality evidence to support the use of cannabinoids for the treatment of chronic pain and spasticity. There was low-quality evidence suggesting that cannabinoids were associated with improvements in nausea and vomiting due to chemotherapy, weight gain in HIV infection, sleep disorders, and Tourette syndrome. Cannabinoids were associated with an increased risk of short-term AEs. (PsycInfo Database Record (c) 2021 APA, all rights reserved)
Despite extensive study over the past decades, available treatments for schizophrenia are only modestly effective and cause serious metabolic and neurological side effects. Therefore, there is an urgent need for novel therapeutic targets for the treatment of schizophrenia. A highly promising new pharmacological target in the context of schizophrenia is the endocannabinoid system. Modulation of this system by the main psychoactive component in cannabis, Δ9-tetrahydrocannabinol (THC), induces acute psychotic effects and cognitive impairment. However, the non-psychotropic, plant-derived cannabinoid agent cannabidiol (CBD) may have antipsychotic properties, and thus may be a promising new agent in the treatment of schizophrenia. Here we review studies that investigated the antipsychotic properties of CBD in human subjects. Results show the ability of CBD to counteract psychotic symptoms and cognitive impairment associated with cannabis use as well as with acute THC administration. In addition, CBD may lower the risk for developing psychosis that is related to cannabis use. These effects are possibly mediated by opposite effects of CBD and THC on brain activity patterns in key regions implicated in the pathophysiology of schizophrenia, such as the striatum, hippocampus and prefrontal cortex. The first small-scale clinical studies with CBD treatment of patients with psychotic symptoms further confirm the potential of CBD as an effective, safe and well-tolerated antipsychotic compound, although large randomised clinical trials will be needed before this novel therapy can be introduced into clinical practice. (PsycInfo Database Record (c) 2021 APA, all rights reserved)
Understanding whether cannabidiol (CBD) is useful and safe for the treatment of psychiatric disorders is essential to empower psychiatrists and patients to take good clinical decisions. Our aim was to conduct a systematic review regarding the benefits and adverse events (AEs) of CBD in the treatment of schizophrenia, psychotic disorders, anxiety disorders, depression, bipolar disorder and substance-use disorders.
METHODS:
We conducted a literature search in PubMed, Scielo, and Clinicaltrials.gov databases. Evidence was classified according to the WFSBP task forces standards.
RESULTS:
Bibliographic research yielded 692 records. After analysis, we included six case reports and seven trials, comprising 201 subjects. Most the studies published presented several drawbacks and did not reach statistical significance. We have not found evidence regarding major depressive and bipolar disorders. The level of evidence for cannabis withdrawal is B; cannabis addiction is C2; treatment of positive symptoms in schizophrenia and anxiety in social anxiety disorder is C1. Discrete or no AEs were reported. The most frequently reported AEs are sedation and dizziness.
CONCLUSIONS:
The evidence regarding efficacy and safety of CBD in psychiatry is still scarce. Further larger well-designed randomised controlled trials are required to assess the effects of CBD in psychiatric disorders. (PsycInfo Database Record (c) 2021 APA, all rights reserved)
