Please use this link to access this publication. Abstract The possible medicinal use of cannabinoids for chronic diseases emphasizes the need to understand the long-term effects of these compounds on the central nervous system. We provide a quantitative synthesis of empirical research pertaining to the non-acute (residual) effects of cannabis on the neurocognitive performance of adult human subjects. Out of 1,014 studies retrieved using a thorough search strategy, only 11 studies met essential a priori inclusion criteria, providing data for a total of 623 cannabis users and 409 non- or minimal users. Neuropsychological results were grouped into 8 ability domains, and effect sizes were calculated by...

Key Points Driving under the influence of cannabis has been identified as a public health concern as medical and recreational cannabis availability increases in some countries. A recent randomized clinical trial found similar levels of acute driving impairment with THC-dominant cannabis and with a combination of THC-CBD equivalent cannabis using on-road driving tests that provided real-world conditions; however, CBD-dominant cannabis did not produce significant cognitive or psychomotor impairment compared with placebo in this trial. Media coverage of this study conveyed the findings as CBD-dominant cannabis not causing driving impairment while THC-dominant cannabis does, with the latter lasting up to 4 h post-dose. It is...

Abstract As cannabinoid-based medications gain popularity in the treatment of refractory medical conditions, it is crucial to examine the neurocognitive effects of commonly prescribed products to ensure associated safety profiles. The present study aims to investigate the acute effects of a standard 1 mL sublingual dose of CannEpil®, a medicinal cannabis oil containing 100 mg cannabidiol (CBD) and 5 mg Δ9-tetrahydrocannabinol (THC) on neurocognition, attention, and mood. A randomised, double-blind, placebo-controlled, within-subjects design assessed 31 healthy participants (16 female, 15 male), aged between 21 and 58 years, over a two-week experimental protocol. Neurocognitive performance outcomes were assessed using the Cambridge Neuropsychological Test Automated Battery, with the Profile of Mood States questionnaire, and the...

Please use this link to access this publication. Abstract This study was designed to test our hypothesis that an ultra-low dose of delta-9 tetrahydrocannabinol (THC) reverses age-dependent cognitive impairments in old mice and to examine the possible biological mechanisms that underlie this behavioral effect. Old female mice aged 24 months that had been injected once with 0.002 mg/kg THC (3–4 orders of magnitudes lower than doses that induce the conventional cannabinoid effects in mice) performed significantly better than vehicle-treated old mice and performed similarly to naive young mice aged 2 months, in 6 different behavioral assays that measured various aspects of memory and learning. The beneficial effect of THC lasted for at least 7 weeks. The single injection...

Abstract Rationale Cannabidiol (CBD) is increasingly used as a sleep aid for insomnia; yet neurocognitive and subjective state effects following daily therapeutic use are unclear. Objectives To measure the effect of daily CBD use on neurocognitive performance and daily subjective mood in a population with primary insomnia. Methods This study used a randomized, placebo-controlled, parallel design incorporating a single-blind placebo run-in week followed by a two-week double-blind dosing period, during which participants consumed 150 mg CBD (N = 15) or placebo (N = 15) sublingually 60-minutes daily before bed. Attention, executive function, reasoning, information processing, working and episodic memory were assessed using the CogPro system at the beginning of...

Please use this link to access this publication. Abstract Objectives  Studies of the neurocognitive impairments resulting from cannabis use have primarily depended on self-reports to classify heavy versus light cannabis use. Several factors such as body mass and individual differences in tetrahydro Cannabinol (THC) metabolism can lead to a large range of circulating levels of THC among persons who report similar cannabis use. This study examined decision-making and attention as a function of urine levels of THC in a sample of adolescents who reported similar frequency of cannabis use. Methods  Adolescents who reported cannabis use at least 4 days per week were assigned to...

Please use this link to access this publication. Abstract Rationale: Cannabis is mostly grown under illegal and unregulated circumstances, which seems to favour a product increasingly high in its main cannabinoid ∆-9-tetrahydrocannabinol (THC). ∆-9-tetrahydrocannabivarin (THCV) is a relatively untested cannabinoid which is said to be a cannabinoid receptor neutral antagonist, and may inhibit the effects of THC. Objectives: To explore the safety and tolerability of repeated THCV administration and its effects on symptoms normally induced by THC in a sample of healthy volunteers. Methods: Ten male cannabis users (<25 use occasions) were recruited for this within-subjects, placebo-controlled, double-blind, cross-over pilot study. 10mg oral pure...

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....

Please use this link to access this publication. Abstract Background The current study examined the independent and interactive effects of HIV and marijuana (MJ) use on brain structure and cognitive function among a sample of HIV-positive (HIV + ) and HIV-negative (HIV–) individuals. Methods Participants (HIV+, n = 48; HIV–, n = 29) individuals underwent cognitive testing, questionnaires about substance use, and brain MRI. The HIV+ group was clinically stable based upon current plasma CD4 count, 50% had undetectable viral load (i.e., < 20 copies/mL), and all were on a stable regimen of cART. Results For HIV+ and HIV- participants, higher levels of MJ use were associated with smaller volumes in the entorhinal...

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...