Cross cutting themes
Jane Hanley, Mark Williams in Fathers and Perinatal Mental Health, 2019
Cannabis is the most widely used recreational drug in the world. It is a combination of stems, leaves and flower buds of the cannabis sativa plant. It can be smoked, eaten or vaporised. When smoked, it is spread onto rolling papers and formed into a cigarette, called a joint. Smoking releases the tetrahydrocannabinol (THC), contained in the cannabis, which is absorbed into the lungs and through the blood stream. It can be ingested by adding to foodstuffs. It can be brewed as a tea or added to milk or soft drinks. Vaporising is done using the same system as e-cigarettes. Tetrahydrocannabinol is responsible for the feelings of euphoria. During the past forty years the potency of TCH content has risen to over 30%, which makes it difficult to determine the short- and long-term effects of cannabis.
ISQ – Pharmacology
Bhaskar Punukollu, Michael Phelan, Anish Unadkat in MRCPsych Part 1 In a Box, 2019
Mechanism of action of other drugs – Alcohol: modulates GABA function, agonist at GABAa receptors. Also acts as an NMDA antagonist and causes decreased release of calcium ions. Modulation of NMDA may lead to memory changes associated with long term use. May also be associated with low or high 5HT levels leading to mood/behaviour changes (low 5HT associated with impulsivity, high 5HT associated with anxiety). Acamprosate: antagonizes the excitatory effects of NMDA (glutamate) in the brain and stimulates inhibitory GABA-ergic transmission. Disulfiram: inhibits aldehyde dehydrogenase. Naltrexone: non-selective opioid receptor antagonist. Opioids (heroin, methadone, codeine): act as agonists at jn (analgesia, positive reinforcement, euphoria) and k receptors (dysphoria, sedation). PCP and ketamine: NMDA antagonists. LSD: 5HT2a agonist. Marijuana: tetrahydrocannabinol alters cerebellar and hippocampal neuronal activity.
The contribution of animal models to our understanding of addictive processes
Philip N. Murphy in The Routledge International Handbook of Psychobiology, 2018
The idea that there was a threshold amount of drug exposure required in order for neuroplastic changes underlying the development of addiction to occur was initially suggested for nicotine addiction (Benowitz and Henningfield 1994, Sofuoglu and LeSage 2012, Benowitz and Henningfield 2013). On the basis of this idea, it was suggested that the development of nicotine addiction could be minimised by reducing the nicotine content in cigarettes, thereby producing subthreshold brain changes. In other words, lowering the nicotine content of cigarettes would be expected to result in drug use without the development of addiction (Hatsukami, Perkins et al. 2010). Recent data support this idea; the prevalence of nicotine dependence was higher for smokers of high versus low nicotine cigarettes (Redner, White et al. 2016). Similar findings have been produced when comparing prevalence of addiction produced by high and low levels of ∆-9-tetrahydrocannabinol (THC) in cannabis (Englund, Freeman et al. 2017).
Cannabis-Impaired driving: ethical considerations for the primary care practitioner
Published in Annals of Medicine, 2023
Katherine Huerne, Carolyn Ells, Roland Grad, Kristian B. Filion, Mark J. Eisenberg
Since cannabis legalization, the production and advertisement of over-the-counter cannabis products have increased, often targeting those with mental health concerns as a way to self-manage symptoms [25]. Cannabis use has also increased during the COVID-19 pandemic [36,37]. Even without an explicit diagnosis, commonly cited reasons for increased cannabis use include anxiety, boredom, stress, and to relax [29]. However, the use of cannabis-related products for the treatment of mental health disorders (e.g. Tourette’s, depression, attention deficit hyperactivity disorder, post-traumatic stress disorder, psychosis, anxiety) is not well supported by scientific research [38]. Cannabis use can also lead to induced psychosis, creating mental health issues in individuals who are otherwise healthy, or lead to schizophrenia or bipolar disorder [39]. On the other hand, nabilone or pharmaceutical grade tetrahydrocannabinol (THC) has been shown to provide a small benefit for anxiety symptoms among patients with chronic non-cancer pain and multiple sclerosis, while prolonged cannabis use has been shown to have medicinal benefits in the management of comorbid conditions like chronic pain, nausea, and muscle spasms [25,38].
Severe outcomes following pediatric cannabis intoxication: a prospective cohort study of an international toxicology surveillance registry
Published in Clinical Toxicology, 2023
Neta Cohen, Mathew Mathew, Jeffrey Brent, Paul Wax, Adrienne L. Davis, Cherie Obilom, Michele M. Burns, Joshua Canning, Kevin Baumgartner, Andrew L. Koons, Timothy J. Wiegand, Bryan Judge, Christopher Hoyte, James A. Chenoweth, Blake Froberg, Henry Farrar, Jennifer L. Carey, Robert G. Hendrickson, Michael Hodgman, E. Martin Caravati, Michael R. Christian, Brian J. Wolk, Steven A. Seifert, Yedidia Bentur, Michael Levine, Lynn A. Farrugia, David Vearrier, Alicia B. Minns, Joseph M. Kennedy, Ron I. Kirschner, Kim Aldy, Suzanne Schuh, Sharan Campleman, Shao Li, Daniel T. Myran, Lisa Feng, Stephen B. Freedman, Yaron Finkelstein
Cannabis edibles are often highly concentrated and can lead to severe intoxication in children, manifested by delayed and prolonged effects, compared to cannabis inhalation [18]. When ingested, tetrahydrocannabinol, a potent psychoactive cannabinoid, is absorbed over 1–3 h, compared to almost instantaneous absorption by inhalation. This time lag may allow continued consumption of edibles by children before CNS and other symptoms appear. The predominance of CNS depression following cannabis intoxication in young children may also represent a greater weight-based CNS dose [19]. Several jurisdictions have implemented measures to mitigate pediatric exposures to cannabis edibles, such as restrictions of the amount of tetrahydrocannabinol in a package and limiting the attractiveness of product packaging [20]. However, such measures may not be sufficient to curb rises in pediatric intoxications, particularly from illegal products that do not comply with regulations.
Compare of optic coherence tomography parameters in recreational synthetic tetrahydrocannabinol use and healthy control
Published in Cutaneous and Ocular Toxicology, 2023
Mehmet Tahir Eski, Kuddusi Teberik, Sezer Taha, Bora Büken, Feruza Turan Sönmez
This prospective study was conducted at the Düzce University Medical Faculty Department of Ophthalmology, Turkey, in accordance with the principles of the Declaration of Helsinki. Approval was granted by the institutional ethics committee (no. 20–17-24). The research protocols and aims were explained to the participants, who all provided informed consent. Two groups were established, one of 56 patients using recreational synthetic tetrahydrocannabinol (Group 1) and a control group of 58 healthy individuals (Group 2). Groups 1 and 2 both consisted of individuals meeting the inclusion and exclusion criteria and consenting to take part. Patients presenting to the forensic medicine department due to recreational synthetic tetrahydrocannabinol use were referred to us. Lucid individuals aged over 18 and using recreational synthetic tetrahydrocannabinol for at least one year were included in the study. Forty-four patients, who were unaware, could not obtain sufficient information, and whose measurements could not be made exactly, were excluded from the study.
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