Abstract Cannabis is one of the oldest crops grown, traditionally held religious attachments in various cultures for its medicinal use much before its introduction to Western medicine. Multiple preclinical and clinical investigations have explored the beneficial effects of cannabis in various neurocognitive and neurodegenerative diseases affecting the cognitive domains. Tetrahydrocannabinol (THC), the major psychoactive component, is responsible for cognition-related deficits, while cannabidiol (CBD), a non-psychoactive phytocannabinoid, has been shown to elicit neuroprotective activity. In the present integrative review, the authors focus on the effects of cannabis on the different cognitive domains, including learning, consolidation, and retrieval. The present study is the first attempt in...

Please use this link to access this publication: https://www.sciencedirect.com/science/article/abs/pii/S0165178123003700 Abstract Recreational cannabis use has recently gained considerable interest as an environmental risk factor that triggers the onset of psychosis. To date, however, the evidence that cannabis is associated with negative outcomes in individuals at clinical high risk (CHR) for psychosis is inconsistent. The present study tracked cannabis usage over a 2-year period and examined its associations with clinical and neurocognitive outcomes, along with medication rates. CHR youth who continuously used cannabis had higher neurocognition and social functioning over time, and decreased medication usage, relative to non-users. Surprisingly, clinical symptoms improved over time despite the medication decreases.

Please use this link to access this publication: https://www.sciencedirect.com/science/article/abs/pii/009130579090028G?via%3Dihub Abstract Three experienced marijuana smokers participated in four 2-day experimental sessions in which they smoked either 0, 1, or 2 marijuana cigarettes containing 2.57% Δ9-tetrahydrocannabinol (THC) at two different times on the first day. A battery of physiological, subjective, and performance measures was repeated throughout day 1 to assess acute effects and on day 2 to measure any residual effects of marijuana. Blood samples were also repeatedly collected to examine the relationship between plasma levels and pharmacological effects of THC. Acutely, marijuana increased heart rate and subjective ratings of drug effects and slightly impaired performance on...

Please use this link to access this publication: https://www.sciencedirect.com/science/article/abs/pii/S0303846720303334?via%3Dihub Abstract Objective: Moderate to severe spasticity is commonly reported in Multiple Sclerosis (MS) and its management is still a challenge. Cannabinoids were recently suggested as add-on therapy for the treatment of spasticity and chronic pain in MS but there is no conclusive scientific evidence on their safety, especially on cognition and over long periods. The aim of this prospective pilot study was to assess the long-term effects of a tetrahydrocannabinol-cannabidiol (THC/CBD) oromucosal spray (Sativex®) on cognition, mood and anxiety. Patients and methods: An extensive and specific battery of neuropsychological tests (Symbol Digit Modalities Test-SDMT, California Verbal Learning Test-CVLT,...

Abstract Learning to associate cues or contexts with potential threats or rewards is adaptive and enhances survival. Both aversive and appetitive memories are therefore powerful drivers of behaviour, but the inappropriate expression of conditioned responding to fear‐ and drug‐related stimuli can develop into anxiety‐related and substance abuse disorders respectively. These disorders are associated with abnormally persistent emotional memories and inadequate treatment, often leading to symptom relapse. Studies show that cannabidiol, the main non‐psychotomimetic phytocannabinoid found in Cannabis sativa, reduces anxiety via 5‐HT1A and (indirect) cannabinoid receptor activation in paradigms assessing innate responses to threat. There is also accumulating evidence from animal studies investigating the effects of...

Abstract The vast majority of states have enacted full or partial medical marijuana (MMJ) programs, causing the number of patients seeking certification for MMJ use to increase dramatically in recent years. Despite increased use of MMJ across the nation, no studies thus far have examined the specific impact of MMJ on cognitive function and related brain activation. In the present study, MMJ patients seeking treatment for a variety of documented medical conditions were assessed prior to initiating MMJ treatment and after 3 months of treatment as part of a larger longitudinal study. In order to examine the effect of MMJ treatment on task-related brain...

Abstract   A generally undesired effect of cannabis smoking is a reversible disruption of short-term memory induced by delta-9-tetrahydrocannabinol (THC), the primary psychoactive component of cannabis. However, this paradigm has been recently challenged by a group of scientists who have shown that THC is also able to improve neurological function in old animals when chronically administered at low concentrations. Moreover, recent studies demonstrated that THC paradoxically promotes hippocampal neurogenesis, prevents neurodegenerative processes occurring in animal models of Alzheimer’s disease, protects from inflammation induced cognitive damage and restores memory and cognitive function in old mice. With the aim to reconcile these seemingly contradictory facts, this...

Abstract Introduction: Chronic cannabis use has been associated with impaired cognition and elevated psychological symptoms, particularly psychotic-like experiences. While D9-tetrahydrocannabinol (THC) is thought to be primarily responsible for these deleterious effects, cannabidiol (CBD) is purported to have antipsychotic properties and to ameliorate cognitive, symptomatic, and brain harms in cannabis users. However, this has never been tested in a prolonged administration trial in otherwise healthy cannabis users. Here, we report the first study of prolonged CBD administration to a community sample of regular cannabis users in a pragmatic trial investigating potential restorative effects of CBD on psychological symptoms and cognition. Materials and Methods: Twenty frequent...

Various lines of (pre)clinical research indicate that cannabinoid agents carry the potential for therapeutic application to reduce symptoms in several psychiatric disorders. However, direct testing of the involvement of cannabinoid brain systems in psychiatric syndromes is essential for further development. In the Pharmacological Imaging of the Cannabinoid System (PhICS) study, the involvement of the endocannabinoid system in cognitive brain function is assessed by comparing acute effects of the cannabinoid agonist Δ9-tetrahydrocannabinol (THC) on brain function between healthy controls and groups of psychiatric patients showing cognitive dysfunction. This article describes the objectives and methods of the PhICS study and presents preliminary results of the administration...

Abstract In an increasing number of states and countries, cannabis now stands poised to join alcohol and tobacco as a legal drug. Quantifying the relative adverse and beneficial effects of cannabis and its constituent cannabinoids should therefore be prioritized. Whereas newspaper headlines have focused on links between cannabis and psychosis, less attention has been paid to the much more common problem of cannabis addiction. Certain cognitive changes have also been attributed to cannabis use, although their causality and longevity are fiercely debated. Identifying why some individuals are more vulnerable than others to the adverse effects of cannabis is now of paramount importance to public...