Please use this link to access this publication. Abstract Background and Hypothesis Up to 43% of people with schizophrenia have a lifetime cannabis use disorder (CUD). Tetrahydrocannabinol (THC) has been shown to exacerbate psychosis in a dose-dependent manner, but little research has assessed its effects on schizophrenia and co-occurring CUD (SCZ-CUD). In this double-dummy, placebo-controlled trial (total n = 130), we hypothesized that a modest dose of THC would worsen cognitive function but not psychosis. Study Design Effects of single-dose oral THC (15 mg dronabinol) or smoked 3.5% THC cigarettes vs placebo in SCZ-CUD or CUD-only on positive and negative symptoms of schizophrenia (only for SCZ-CUD), cognition, and...

Abstract Objective Cannabis is associated with psychotic outcomes in numerous studies, an effect that is commonly attributed to Δ 9-tetrahydrocannabinol (Δ 9-THC). An increasing number of authors identify cannabidiol, another component of the cannabis plant, as an antipsychotic agent. The objective of the current study is to investigate the role of cannabidiol content in the association between cannabis use and psychiatric symptoms in a large non-clinical population of cannabis users. Methods In a web-based cross-sectional study we obtained detailed information about cannabis use and subclinical psychiatric experiences using the Community Assessment of Psychic Experiences (CAPE). Different types of cannabis (i.e. marijuana, hashish etc.) have distinctive...

Please use this link to access this publication. Abstract Cannabis use has been associated with an increased risk to develop schizophrenia as well as symptom exacerbation in patients. In contrast, clinical studies have revealed an inverse relationship between the cerebrospinal fluid levels of the endocannabinoid anandamide and symptom severity, suggesting a therapeutic potential for endocannabinoid-enhancing drugs. Indeed, preclinical studies have shown that these drugs can reverse distinct behavioral deficits in a rodent model of schizophrenia. The mechanisms underlying the differences between exogenous and endogenous cannabinoid administration are currently unknown. Using the phencyclidine (PCP) rat model of schizophrenia, we compared the effects on neuronal activity...

Please use this link to access this publication. Abstract 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....

Abstract The main active ingredient in cannabis, delta-9-tetrahydrocannabinol (THC), can acutely induce psychotic symptoms and impair episodic and working memory. Another major constituent, cannabidiol (CBD), may attenuate these effects. This study aimed to determine the effects of THC and CBD, both alone and in combination on psychotic symptoms and memory function. A randomised, double-blind crossover design compared the effects of (i) placebo, (ii) THC 8 mg, (iii) CBD 16 mg and (iv) THC 8 mg + CBD 16 mg administered by inhalation through a vaporiser. Using an experimental medicine approach to predict treatment sensitivity, we selected 48 cannabis users from the community on the basis of (1) schizotypal personality questionnaire...

Please use this link to access this publication. Abstract Rationale Preliminary evidence suggests that cannabidiol (CBD) may be effective in the treatment of neurodegenerative disorders; however, CBD has never been evaluated for the treatment of cognitive impairments associated with schizophrenia (CIAS). Objective This study compared the cognitive, symptomatic, and side effects of CBD versus placebo in a clinical trial. Methods This study was a 6-week, randomized, placebo-controlled, parallel group, fixed-dose study of oral CBD (600 mg/day) or placebo augmentation in 36 stable antipsychotic-treated patients diagnosed with chronic schizophrenia. All subjects completed the MATRICS Consensus Cognitive Battery (MCCB) at baseline and at end of 6 weeks of...

Please use this link to access this publication. Abstract Purpose: Twenty-nine states have bypassed federal regulations by legalizing marijuana (MJ) either medicinally, recreationally or both. The FDA states that there is no empirical evidence that MJ is effective to treat these disorders. With over a billion individuals living with a disability across the globe, it is crucial to fully research the efficaciousness and safety of medical MJ to treat this population. The purpose to present the results of a scoping review of studies focused on the levels of evidence currently available on medical MJ’s efficacy in treatment across a large range of disabilities. Methods: Databases were...

Abstract The neurobiological mechanisms underlying the association between cannabis use and acute or long-lasting psychosis are not completely understood. While some evidence suggests altered striatal dopamine may underlie the association, direct evidence that cannabis use affects either acute or chronic striatal dopamine is inconclusive. In contrast, pre-clinical research suggests that cannabis may affect dopamine via modulation of glutamate signaling. A double-blind, randomized, placebo-controlled, crossover design was used to investigate whether altered striatal glutamate, as measured using proton magnetic resonance spectroscopy, underlies the acute psychotomimetic effects of intravenously administered delta-9-tetrahydrocannabinol (Δ9-THC; 1.19 mg/2 ml), the key psychoactive ingredient in cannabis, in a set of 16 healthy participants...

Abstract The treatment of patients with schizophrenia and substance use disorder poses a challenge for clinicians. Continued use of cannabis and cocaine can exacerbate psychotic symptoms and worsen the course of disease. To date, no pharmacotherapy is available for patients with cannabis use disorder (CUD). Cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) are the main active constituents in Cannabis sativa, with the latter being linked to an increased risk of psychosis. We describe a clinical case of a male patient diagnosed with schizophrenia, combined personality disorder, CUD and cocaine use disorder. Over the course of 8 years, he was hospitalized 30 times due to psychotic relapses and...

Please use this link to access this publication. Abstract Rationale Antipsychotics help alleviate the positive symptoms associated with schizophrenia; however, their debilitating side effects have spurred the search for better treatment options. Novel compounds can be screened for antipsychotic potential in neuronal cell cultures and following acute N-methyl-D-aspartate (NMDA) receptor blockade with non-competitive antagonists such as MK-801 in rodent behavioral models. Given the known interactions between NMDA receptors and type 1 cannabinoid receptors (CB1R), compounds that modulate CB1Rs may have therapeutic potential for schizophrenia. Objectives This study assessed whether the CB1R positive allosteric modulator GAT211, when compared to ∆9-tetrahydrocannabinol (THC), has potential to reduce...