The Effects of Cannabinoids on Executive Functions: Evidence from Cannabis and Synthetic Cannabinoids—A Systematic Review

Abstract

Background—Cannabis is the most popular illicit drug in the Western world. Repeated cannabis use has been associated with short and long-term range of adverse effects. Recently, new types of designer-drugs containing synthetic cannabinoids have been widespread. These synthetic cannabinoid drugs are associated with undesired adverse effects similar to those seen with cannabis use, yet, in more severe and long-lasting forms. Method—A literature search was conducted using electronic bibliographic databases up to 31 December 2017. Specific search strategies were employed using multiple keywords (e.g., “synthetic cannabinoids AND cognition,” “cannabis AND cognition” and “cannabinoids AND cognition”). Results—The search has yielded 160 eligible studies including 37 preclinical studies (5 attention, 25 short-term memory, 7 cognitive flexibility) and 44 human studies (16 attention, 15 working memory, 13 cognitive flexibility). Both pre-clinical and clinical studies demonstrated an association between synthetic cannabinoids and executive-function impairment either after acute or repeated consumptions. These deficits differ in severity depending on several factors including the type of drug, dose of use, quantity, age of onset and duration of use. Conclusions—Understanding the nature of the impaired executive function following consumption of synthetic cannabinoids is crucial in view of the increasing use of these drugs.

Modulatory effects of cannabinoids on brain neurotransmission

“…In contrast to Δ9‐Tetrahydrocannabinol (Δ9‐THC) which is the main psychoactive constituent of cannabis, SCs are more potent and efficacious at cannabinoid CB 1 and CB 2 receptors (Pertwee, ; Bhattacharyya et al ., ; Castaneto et al ., ). Therefore, although SC drugs are designed to mimic the effects of cannabis, they induce more severe and persistent adverse effects since they include more potent and toxic psychoactive compounds than traditional cannabis (Fattore, ; Cohen et al ., ; Cohen & Weinstein, ,b; Langer et al ., ; Shalit et al ., ; van Amsterdam et al ., ; Weinstein et al ., ).…”

Medical cannabis: What practitioners need to know

“…The addition of CBD to products containing THC has been shown to reduce the risk of impaired cognition. [54,55] Some unregulated cannabis products have been assessed and found to vary in their THC and CBD content when compared to information on the label, and some commercially available products sold as pure CBD contain marked amounts of THC. [29,30] This may affect cognition, and where children and adolescents are concerned, this is particularly important, given the potential for the impact on brain development, cognitive function and mental illness.…”

Sentetik Kannabinoidlerin Nöropsikiyatrik Etkileri

“…Sürücüler ile yapılan başka bir çalışmaya göre de bir SK türevi olan UR-144'ün esrara göre psikomotor becerileri ve sürücü performansını daha olumsuz etkilediği bildirilmiştir 29 . 31 . Bazı çalışmalarda kronik kullanımda esrar kullanıcılarının çalışma belleği performansının daha kötü 32,33 ; bazı çalışmalarda kontrol grubuyla eş düzeyde olduğu bulunmuştur 34,35 .…”