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Effects of Cannabis Use on Human Behavior, Including Cognition, Motivation, and Psychosis: A Review.JAMA Psychiatry Mar 2016With a political debate about the potential risks and benefits of cannabis use as a backdrop, the wave of legalization and liberalization initiatives continues to... (Review)
Review
With a political debate about the potential risks and benefits of cannabis use as a backdrop, the wave of legalization and liberalization initiatives continues to spread. Four states (Colorado, Washington, Oregon, and Alaska) and the District of Columbia have passed laws that legalized cannabis for recreational use by adults, and 23 others plus the District of Columbia now regulate cannabis use for medical purposes. These policy changes could trigger a broad range of unintended consequences, with profound and lasting implications for the health and social systems in our country. Cannabis use is emerging as one among many interacting factors that can affect brain development and mental function. To inform the political discourse with scientific evidence, the literature was reviewed to identify what is known and not known about the effects of cannabis use on human behavior, including cognition, motivation, and psychosis.
Topics: Adult; Behavior; Cannabis; Cognition; Humans; Legislation, Drug; Marijuana Abuse; Motivation; Psychoses, Substance-Induced; United States
PubMed: 26842658
DOI: 10.1001/jamapsychiatry.2015.3278 -
Nature Reviews. Disease Primers Feb 2021Cannabis use disorder (CUD) is an underappreciated risk of using cannabis that affects ~10% of the 193 million cannabis users worldwide. The individual and public health... (Review)
Review
Cannabis use disorder (CUD) is an underappreciated risk of using cannabis that affects ~10% of the 193 million cannabis users worldwide. The individual and public health burdens are less than those of other forms of drug use, but CUD accounts for a substantial proportion of persons seeking treatment for drug use disorders owing to the high global prevalence of cannabis use. Cognitive behavioural therapy, motivational enhancement therapy and contingency management can substantially reduce cannabis use and cannabis-related problems, but enduring abstinence is not a common outcome. No pharmacotherapies have been approved for cannabis use or CUD, although a number of drug classes (such as cannabinoid agonists) have shown promise and require more rigorous evaluation. Treatment of cannabis use and CUD is often complicated by comorbid mental health and other substance use disorders. The legalization of non-medical cannabis use in some high-income countries may increase the prevalence of CUD by making more potent cannabis products more readily available at a lower price. States that legalize medical and non-medical cannabis use should inform users about the risks of CUD and provide information on how to obtain assistance if they develop cannabis-related mental and/or physical health problems.
Topics: Analgesics; Cannabis; Cognitive Behavioral Therapy; Humans; Marijuana Abuse; Prevalence
PubMed: 33627670
DOI: 10.1038/s41572-021-00247-4 -
Psychopharmacology Bulletin Jan 2021This comprehensive review discusses the adverse effects known today about marijuana, for either medical or recreational use. It reviews the role of cannabis in the... (Review)
Review
PURPOSE OF REVIEW
This comprehensive review discusses the adverse effects known today about marijuana, for either medical or recreational use. It reviews the role of cannabis in the treatment of chronic pain, cognitive and neurological adverse effects, special cases and addiction.
RECENT FINDINGS
Cannabinoids work through the endocannabinoids system and inhibit the release of GABA and glutamate in the brain, impact neuromodulation, as well as dopamine, acetylcholine and norepinephrine release. They affect reward, learning and pain. The use of cannabis is increasing nationally and world-wide for both recreational and medicinal purposes, however, there is relatively only low quality evidence to the efficacy and adverse effects of this. Cannabis and its derivatives may be used for treatment of chronic pain. They are via CB1 receptors that are thought to modulate nociceptive signals in the brain. CB2 receptors in the DRG likely affect pain integration in the afferent pathways, and peripherally CB2 also affects noradrenergic pathways influencing pain. A large proportion of users may see more than 50% of chronic pain alleviation compared with placebo. Cannabis affects cognition, most notably executive function, memory and attention, and may deteriorate the boundary between emotional and executive processing. Cannabis impairs memory in the short run, which become more significant with chronic use, and may also be accompanied by poorer effort, slower processing and impacted attention. It is generally believed that long-term use and earlier age are risk factor for neurocognitive deficits; neuroimaging studies have shown reduced hippocampal volume and density. Executive functions and memory are worse in adolescent users versus adults. Cannabis addiction is different and likely less common than other addictive substances, but up to 10% of users meet criteria for lifetime cannabis dependence. Addiction patterns may be linked to genetic and epigenetic differences. It is still unclear whether abstinence reverses patterns of addiction, and more research is required into this topic.
SUMMARY
Cannabis use has become more abundant for both medical and recreational use. It carries likely benefits in the form of analgesia, anti-emesis and improved appetite in chronic patients. The evidence reviewing adverse effects of this use are still limited, however, exiting data points to a clear link with neurocognitive deterioration, backed by loss of brain volume and density. Addiction is likely complex and variable, and no good data exists to support treatment at this point. It is becoming clear that use in earlier ages carries a higher risk for long-term deficits. As with any other drug, these risks should be considered alongside benefits prior to a decision on cannabis use.
Topics: Adolescent; Adult; Cannabinoids; Cannabis; Cognition; Humans; Marijuana Abuse; Medical Marijuana
PubMed: 33897066
DOI: No ID Found -
Current Pharmaceutical Design 2014This article reviews neuroimaging, neurocognitive, and preclinical findings on the effects of cannabis on the adolescent brain. Marijuana is the second most widely used... (Review)
Review
This article reviews neuroimaging, neurocognitive, and preclinical findings on the effects of cannabis on the adolescent brain. Marijuana is the second most widely used intoxicant in adolescence, and teens who engage in heavy marijuana use often show disadvantages in neurocognitive performance, macrostructural and microstructural brain development, and alterations in brain functioning. It remains unclear whether such disadvantages reflect pre-existing differences that lead to increased substances use and further changes in brain architecture and behavioral outcomes. Future work should focus on prospective investigations to help disentangle dose-dependent effects from pre-existing effects, and to better understand the interactive relationships with other commonly abused substances (e.g., alcohol) to better understand the role of regular cannabis use on neurodevelopmental trajectories.
Topics: Adolescent; Brain; Cannabis; Cerebrovascular Circulation; Cognition; Electroencephalography; Humans; Magnetic Resonance Imaging; Neuroimaging
PubMed: 23829363
DOI: 10.2174/13816128113199990426 -
Molecules (Basel, Switzerland) Dec 2020Terpenes are the primary constituents of essential oils and are responsible for the aroma characteristics of cannabis. Together with the cannabinoids, terpenes... (Review)
Review
Terpenes are the primary constituents of essential oils and are responsible for the aroma characteristics of cannabis. Together with the cannabinoids, terpenes illustrate synergic and/or entourage effect and their interactions have only been speculated in for the last few decades. Hundreds of terpenes are identified that allude to cannabis sensory attributes, contributing largely to the consumer's experiences and market price. They also enhance many therapeutic benefits, especially as aromatherapy. To shed light on the importance of terpenes in the cannabis industry, the purpose of this review is to morphologically describe sources of cannabis terpenes and to explain the biosynthesis and diversity of terpene profiles in different cannabis chemovars.
Topics: Biosynthetic Pathways; Cannabinoids; Cannabis; Oils, Volatile; Phenotype; Terpenes; Volatile Organic Compounds
PubMed: 33302574
DOI: 10.3390/molecules25245792 -
Pharmacology 2020Cannabis abuse is a common phenomenon among adolescents. The dominant psychoactive substance in Cannabis sativa is tetrahydrocannabinol (THC). However, in the past 40... (Review)
Review
Cannabis abuse is a common phenomenon among adolescents. The dominant psychoactive substance in Cannabis sativa is tetrahydrocannabinol (THC). However, in the past 40 years the content of the psychoactive ingredient THC in most of the preparations is not constant but has increased due to other breeding and culturing conditions. THC acts as the endocannabinoids at CB1 and CB2 receptors but pharmacologically can be described as a partial (not a pure) agonist. Recent evidence shows that activation of the CB1 receptor by THC can diminish the production of neuronal growth factor in neurons and affect other signalling cascades involved in synapsis formation. Since these factors play an important role in the brain development and in the neuronal conversion processes during puberty, it seems reasonable that THC can affect the adolescent brain in another manner than the adult brain. Accordingly, in adolescent cannabis users structural changes were observed with loss of grey matter in certain brain areas. Moreover, recent studies show different effects of THC on adolescent and adult brains and on behaviour. These studies indicate that early THC abuse can result in neuropsychological deficits. This review gives an overview over the present knowledge in this field.
Topics: Adolescent; Adult; Behavior; Brain; Cannabis; Dronabinol; Endocannabinoids; Humans; Marijuana Abuse; Receptors, Cannabinoid
PubMed: 32629444
DOI: 10.1159/000509377 -
Psychopharmacology Bulletin May 2020This is a comprehensive review of the association between cannabis use and psychological disorders. It reviews the latest and seminal evidence that is available and... (Meta-Analysis)
Meta-Analysis Review
PURPOSE OF REVIEW
This is a comprehensive review of the association between cannabis use and psychological disorders. It reviews the latest and seminal evidence that is available and attempts to conclude the strength of such association.
RECENT FINDINGS
Cannabis is a flowering plant with psychoactive properties, attributed to cannabinoids that naturally occur within the plant. These act through the CB1 and CB2 receptors to inhibit GABA and glutamate release, as well through other forms of neuromodulation through the modulation of the endocannabinoid system (eCBs); a system that is otherwise involved in different pathways, including reward, memory, learning, and pain. Recent societal changes have increased the use of both medical and recreational cannabis. Patients with mental illness are considered more vulnerable and are prone to reward-seeking behavior. Cannabis use disorder (CUD) has been shown to have an increased prevalence in individuals with mental illness, creating an explosive cocktail. Approximately 1 in 4 patients with schizophrenia are also diagnosed with CUD. Cannabis use is associated with 2-4 times the likelihood of developing psychosis in healthy individuals. It has also been associated with multiple poor prognostic factors in schizophrenia, as well as in patients with a history of psychosis who do not meet diagnostic criteria for schizophrenia. Cannabis has been linked with anxiety; THC has been shown to elicit anxiety; however, anxiety is also a trigger for cannabis use. However, a recent large meta-analysis did not find a convincing link between cannabis and anxiety. This was reiterated in a recent epidemiological study that did not find such a correlation; however, it did identify a link between cannabis use, substance disorder, alcohol use disorder, drug use disorder, and nicotine dependence. Similarly, contradicting data exists regarding the link of depression and cannabis use.
SUMMARY
Cannabis use is increasing with recent societal shifts; however, its interaction with mental health is less well understood. CUD is highly prevalent in individuals with mental health disorders, especially those with other substance abuse disorders. There is evidence to support that cannabis use may trigger and worsen psychosis and schizophrenia. The link with depression and anxiety is less clear and needs further investigation. Personality disorder is linked with substance use disorder and shares similar risk factors with CUD.
Topics: Anxiety Disorders; Cannabis; Comorbidity; Humans; Marijuana Abuse; Psychotic Disorders; Substance-Related Disorders
PubMed: 32508368
DOI: No ID Found -
The New England Journal of Medicine Jun 2014
Review
Topics: Accidents, Traffic; Adolescent; Adult; Age Factors; Brain; Cannabinoids; Cannabis; Dronabinol; Humans; Lung Diseases; Marijuana Abuse; Marijuana Smoking; United States
PubMed: 24897085
DOI: 10.1056/NEJMra1402309 -
Dialogues in Clinical Neuroscience Sep 2017Cannabis (also known as marijuana) is the most frequently used illicit psychoactive substance in the world. Though it was long considered to be a "soft" drug, studies... (Review)
Review
Cannabis (also known as marijuana) is the most frequently used illicit psychoactive substance in the world. Though it was long considered to be a "soft" drug, studies have proven the harmful psychiatric and addictive effects associated with its use. A number of elements are responsible for the increased complications of cannabis use, including the increase in the potency of cannabis and an evolution in the ratio between the two primary components, Δ-tetrahydrocannabinol (Δ-THC) and cannabidiol (toward a higher proportion of Δ-THC), Synthetic cannabinoid (SC) use has rapidly progressed over the last few years, primarily among frequent cannabis users, because SCs provide similar psychoactive effects to cannabis. However, their composition and pharmacological properties make them dangerous substances. Cannabis does have therapeutic properties for certain indications. These therapeutic applications pertain only to certain cannabinoids and their synthetic derivatives. The objective of this article is to summarize current developments concerning cannabis and the spread of SCs. Future studies must further explore the benefit-risk profile of medical cannabis use.
Topics: Cannabinoids; Cannabis; Humans; Psychoses, Substance-Induced
PubMed: 29302228
DOI: 10.31887/DCNS.2017.19.3/glafaye -
Nature Reviews. Neuroscience May 2016In 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... (Review)
Review
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 health. Here, we review the current state of knowledge about such vulnerability factors, the variations in types of cannabis, and the relationship between these and cognition and addiction.
Topics: Animals; Behavior, Addictive; Brain; Cannabis; Case-Control Studies; Cognition; Humans; Marijuana Smoking; Receptor, Cannabinoid, CB1; Risk Factors
PubMed: 27052382
DOI: 10.1038/nrn.2016.28