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The Lancet. Psychiatry Jun 2023The relationship between psychotic disorders and cannabis use is heavily debated. Shared underlying genetic risk is one potential explanation. We investigated the...
BACKGROUND
The relationship between psychotic disorders and cannabis use is heavily debated. Shared underlying genetic risk is one potential explanation. We investigated the genetic association between psychotic disorders (schizophrenia and bipolar disorder) and cannabis phenotypes (lifetime cannabis use and cannabis use disorder).
METHODS
We used genome-wide association summary statistics from individuals with European ancestry from the Psychiatric Genomics Consortium, UK Biobank, and International Cannabis Consortium. We estimated heritability, polygenicity, and discoverability of each phenotype. We performed genome-wide and local genetic correlations. Shared loci were identified and mapped to genes, which were tested for functional enrichment. Shared genetic liabilities to psychotic disorders and cannabis phenotypes were explored using causal analyses and polygenic scores, using the Norwegian Thematically Organized Psychosis cohort.
FINDINGS
Psychotic disorders were more heritable than cannabis phenotypes and more polygenic than cannabis use disorder. We observed positive genome-wide genetic correlations between psychotic disorders and cannabis phenotypes (range 0·22-0·35) with a mixture of positive and negative local genetic correlations. Three to 27 shared loci were identified for the psychotic disorder and cannabis phenotype pairs. Enrichment of mapped genes implicated neuronal and olfactory cells as well as drug-gene targets for nicotine, alcohol, and duloxetine. Psychotic disorders showed a causal effect on cannabis phenotypes, and lifetime cannabis use had a causal effect on bipolar disorder. Of 2181 European participants from the Norwegian Thematically Organized Psychosis cohort applied in polygenic risk score analyses, 1060 (48·6%) were females and 1121 (51·4%) were males (mean age 33·1 years [SD 11·8]). 400 participants had bipolar disorder, 697 had schizophrenia, and 1044 were healthy controls. Within this sample, polygenic scores for cannabis phenotypes predicted psychotic disorders independently and improved prediction beyond the polygenic score for the psychotic disorders.
INTERPRETATION
A subgroup of individuals might have a high genetic risk of developing a psychotic disorder and using cannabis. This finding supports public health efforts to reduce cannabis use, particularly in individuals at high risk or patients with psychotic disorders. Identified shared loci and their functional implications could facilitate development of novel treatments.
FUNDING
US National Institutes of Health, the Research Council Norway, the South-East Regional Health Authority, Stiftelsen Kristian Gerhard Jebsen, EEA-RO-NO-2018-0535, European Union's Horizon 2020 Research and Innovation Programme, the Marie Skłodowska-Curie Actions, and University of Oslo Life Science.
Topics: Animals; Schizophrenia; Bipolar Disorder; Cannabis; Genome-Wide Association Study; Marijuana Abuse; Substance-Related Disorders; Genetic Predisposition to Disease
PubMed: 37208114
DOI: 10.1016/S2215-0366(23)00143-8 -
Journal of Gastrointestinal and Liver... Sep 2019Emesis is an essential survival response, because consumption of food is a key element in the survival behavior and the act of feeding can expose the majority of... (Review)
Review
BACKGROUND
Emesis is an essential survival response, because consumption of food is a key element in the survival behavior and the act of feeding can expose the majority of internal organs to toxins, altered food, viruses, bacteria or fungi. The relationship between visceral or vestibular stimuli and the anatomical structures of the brain-gut axis explain the modulation of the gastrointestinal response. We aimed to review comprehensively the current knowledge on emesis occurring in the disorders of brain-gut interaction (DBGI), i.e. functional conditions presenting with emesis.
METHODS
PubMed, Cochrane Library, EMBASE and WILEY databases were screened for relevant publications from the last 20 years regarding brain-gut disorders manifesting emesis. We included in the search also idiopathic gastroparesis, as a condition paralleling the postprandial distress syndrome.
RESULTS
We critically analyzed 2 articles about chronic nausea and vomiting syndrome, 9 articles about cyclic vomiting syndrome, 9 articles about cannabinoid hyperemesis, 10 articles about idiopathic gastroparesis and 6 articles about gastroparesis like-syndrome. Contradictory results regarding the implication of environmental factors in the development of emesis in DBGI demonstrate that the underlying pathogenesis is still not completely understood.
Topics: Animals; Brain; Cannabinoids; Gastric Emptying; Gastrointestinal Tract; Gastroparesis; Humans; Marijuana Abuse; Reflex; Risk Factors; Vomiting
PubMed: 31517329
DOI: 10.15403/jgld-236 -
Child and Adolescent Psychiatric... Jan 2023This review summarizes treatments for cannabis use disorder (CUD) in adolescents. The best supported CUD treatments are cognitive behavioral psychotherapies, including... (Review)
Review
This review summarizes treatments for cannabis use disorder (CUD) in adolescents. The best supported CUD treatments are cognitive behavioral psychotherapies, including family-based models that facilitate environmental changes and youth-focused models that incorporate skills training, motivational interviewing, and contingency management to promote reductions in cannabis use. Some medications show promise in reducing cannabis craving and withdrawal symptoms. Further research is needed on the efficacy and implementation of existing treatments given the changes in cannabis use trends over time and on emerging technologies that may expand access to evidence-based CUD treatments.
Topics: Adolescent; Humans; Cannabis; Marijuana Abuse; Substance-Related Disorders; Motivational Interviewing; Substance Withdrawal Syndrome
PubMed: 36410901
DOI: 10.1016/j.chc.2022.07.006 -
Schizophrenia Bulletin Mar 2015Many people with schizophrenia smoke cannabis, and it is unclear why a large proportion do so and if the effects are harmful or beneficial. It is also unclear what the... (Review)
Review
BACKGROUND
Many people with schizophrenia smoke cannabis, and it is unclear why a large proportion do so and if the effects are harmful or beneficial. It is also unclear what the best method is to allow people with schizophrenia to alter their cannabis intake.
OBJECTIVES
To assess the effects of specific psychological treatments for cannabis reduction in people with schizophrenia. To assess the effects of antipsychotics for cannabis reduction in people with schizophrenia. To assess the effects of cannabinoids (cannabis-related chemical compounds derived from cannabis or manufactured) for symptom reduction in people with schizophrenia.
SEARCH METHODS
We searched the Cochrane Schizophrenia Group Trials Register (August 2013) and all references of articles selected for further relevant trials. We contacted the first author of included studies for unpublished trials or data.
SELECTION CRITERIA
We included all randomized controlled trials involving cannabinoids and schizophrenia/schizophrenia-like illnesses, which assessed: (1) treatments to reduce cannabis use in people with schizophrenia and (2) the effects of cannabinoids on people with schizophrenia.
CONCLUSIONS
Results are limited and inconclusive due to the small number and size of randomized controlled trials available and quality of data reporting within these trials. Currently, there is no evidence to demonstrate that one type of adjunct psychological therapy or one type of drug therapy is more effective than another. There is also insufficient evidence to show that cannabidiol has an antipsychotic effect.
Topics: Cannabinoids; Comorbidity; Humans; Marijuana Abuse; Schizophrenia
PubMed: 25552590
DOI: 10.1093/schbul/sbu168 -
Ugeskrift For Laeger Feb 2015Cannabis is the world's most popular illicit drug, and around half of all Danes have tried it at least once. In this paper we review the pharmacodynamic and... (Review)
Review
Cannabis is the world's most popular illicit drug, and around half of all Danes have tried it at least once. In this paper we review the pharmacodynamic and pharmacokinetic properties of cannabis. We also discuss the treatment of cannabis intoxication and present data from The Danish Poison Information Center.
Topics: Age Distribution; Cannabinoids; Cannabis; Denmark; Drug Interactions; Humans; Illicit Drugs; Marijuana Abuse; Poison Control Centers; Substance Withdrawal Syndrome
PubMed: 25650575
DOI: No ID Found -
Current Opinion in Psychology Apr 2021How to treat adults and adolescents with a Cannabis Use Disorder is a burgeoning research area. This article reviews the empirical literature pertaining to several... (Review)
Review
How to treat adults and adolescents with a Cannabis Use Disorder is a burgeoning research area. This article reviews the empirical literature pertaining to several psychosocial approaches (cognitive-behavior therapy, motivational enhancement, and contingency management), all of which are associated with favorable outcomes. We also review the emerging research on the use of pharmacotherapy, brief interventions and technology-delivered interventions, and conclude with an overview of future research needs.
Topics: Adolescent; Adult; Cannabis; Cognitive Behavioral Therapy; Humans; Marijuana Abuse; Motivation
PubMed: 33338844
DOI: 10.1016/j.copsyc.2020.11.002 -
Nature Neuroscience May 2020There have been dramatic changes worldwide in the attitudes toward and consumption of recreational and medical cannabis. Cannabinoid receptors, which mediate the actions... (Review)
Review
There have been dramatic changes worldwide in the attitudes toward and consumption of recreational and medical cannabis. Cannabinoid receptors, which mediate the actions of cannabis, are abundantly expressed in brain regions known to mediate neural processes underlying reward, cognition, emotional regulation and stress responsivity relevant to addiction vulnerability. Despite debates regarding potential pathological consequences of cannabis use, cannabis use disorder is a clinical diagnosis with high prevalence in the general population and that often has its genesis in adolescence and in vulnerable individuals associated with psychiatric comorbidity, genetic and environmental factors. Integrated information from human and animal studies is beginning to expand insights regarding neurobiological systems associated with cannabis use disorder, which often share common neural characteristics with other substance use disorders, that could inform prevention and treatment strategies.
Topics: Animals; Brain; Humans; Marijuana Abuse
PubMed: 32251385
DOI: 10.1038/s41593-020-0611-0 -
Current Pharmaceutical Design Jan 2017Globally, the most widely used set of compounds among the internationally regulated drugs is cannabis. (Review)
Review
BACKGROUND
Globally, the most widely used set of compounds among the internationally regulated drugs is cannabis.
OBJECTIVE
To review evidence from epidemiological research on cannabis, organized in relation to this field's five main rubrics: quantity, location, causes, mechanisms, and prevention/ control.
METHOD
The review covers a selection of evidence from standardized population surveys, official statistics, and governmental reports, as well as published articles and books identified via MEDLINE, Web of Science, and Google Scholar as of July 2016.
RESULTS
In relation to quantity, an estimated 3% to 5% of the world population is thought to have tried a cannabis product, with at least one fairly recent use, mainly extra-medical and outside boundaries of prescribed use. Among cannabis users in the United States, roughly one in 7-8 has engaged in medical marijuana use. In relation to location, prevalence proportions reveal important variations across countries and between subgroups within countries. Regarding causes and mechanisms of starting to use cannabis, there is no compelling integrative and replicable conceptual model or theoretical formulation. Most studies of mechanisms have focused upon a 'gateway sequence' and person-to-person diffusion, with some recent work on disability-adjusted life years. A brief review of cannabis use consequences, as well as prevention and control strategies is also provided.
CONCLUSION
At present, we know much about the frequency and occurrence of cannabis use, with too little replicable definitive evidence with respect to the other main rubrics. Given a changing regulatory environment for cannabis products, new institutions such as an independent International Cannabis Products Safety Commission may be required to produce evidence required to weigh benefits versus costs. It is not clear that governmentsponsored research will be sufficient to meet consumer demand for balanced points of view and truly definitive evidence.
Topics: Cannabis; Humans; Marijuana Abuse; Medical Marijuana
PubMed: 27526792
DOI: 10.2174/1381612822666160813214023 -
Journal of Neurochemistry Jun 2021Cannabis sativa is the most widely used illicit drug in the world. Its main psychoactive component is delta-9-tetrahydrocannabinol (THC), one of over 100... (Review)
Review
Cannabis sativa is the most widely used illicit drug in the world. Its main psychoactive component is delta-9-tetrahydrocannabinol (THC), one of over 100 phytocannabinoid compounds produced by the cannabis plant. THC is the primary compound that drives cannabis abuse potential and is also used and prescribed medically for therapeutic qualities. Despite its therapeutic potential, a significant subpopulation of frequent cannabis or THC users will develop a drug use syndrome termed cannabis use disorder. Individuals suffering from cannabis use disorder exhibit many of the hallmarks of classical addictions including cravings, tolerance, and withdrawal symptoms. Currently, there are no efficacious treatments for cannabis use disorder or withdrawal symptoms. This makes both clinical and preclinical research on the neurobiological mechanisms of these syndromes ever more pertinent. Indeed, basic research using animal models has provided valuable evidence of the neural molecular and cellular actions of cannabis that mediate its behavioral effects. One of the main components being central action on the cannabinoid type-one receptor and downstream intracellular signaling related to the endogenous cannabinoid system. Back-translational studies have provided insight linking preclinical basic and behavioral biology research to better understand symptoms observed at the clinical level. This narrative review aims to summarize major research elucidating the molecular, cellular, and behavioral manifestations of cannabis/THC use that play a role in cannabis use disorder and withdrawal.
Topics: Animals; Dronabinol; Drug Tolerance; Endocannabinoids; Humans; Marijuana Abuse; Marijuana Smoking; Receptors, Cannabinoid; Substance Withdrawal Syndrome
PubMed: 33891706
DOI: 10.1111/jnc.15369 -
Journal of Pediatric Psychology Apr 2016The purpose of this commentary was to briefly summarize the literature on the relationship between adolescent marijuana use and mental health and how policy changes... (Review)
Review
OBJECTIVE
The purpose of this commentary was to briefly summarize the literature on the relationship between adolescent marijuana use and mental health and how policy changes surrounding marijuana decriminalization and legalization might impact this relationship.
METHODS
A comprehensive literature search on adolescent marijuana use, mental health, and the impact of decriminalization and legalization was conducted. Findings are briefly summarized and discussed.
RESULTS
Although there is a great deal of ambiguity regarding the causal direction of marijuana use and mental health problems, what can safely be gleaned from this body of research is that early and frequent use of marijuana during adolescence is associated with the development of more psychiatric-related problems than occasional use or nonuse.
CONCLUSIONS
Until there is greater clarity in this domain, clinicians should continue to screen adolescent patients for marijuana use as well as mental health difficulties, but may need to be more thoughtful about screening among early adolescents, if in fact a shift in the age of marijuana uptake occurs amidst policy changes.
Topics: Adolescent; Adolescent Behavior; Health Policy; Humans; Marijuana Abuse; Mental Disorders
PubMed: 26883502
DOI: 10.1093/jpepsy/jsw005