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Neuropsychopharmacology : Official... Jan 2014What is the defining property of addiction? We dust off a several-decades-long debate about the relative importance of two forms of reinforcement—positive... (Review)
Review
What is the defining property of addiction? We dust off a several-decades-long debate about the relative importance of two forms of reinforcement—positive reinforcement, subjectively linked to drug-induced euphoria, and negative reinforcement, subjectively linked to the alleviation of pain—both of which figure importantly in addiction theory; each of these forms has dominated addiction theory in its time. We agree that addiction begins with the formation of habits through positive reinforcement and that drug-opposite physiological responses often establish the conditions for negative reinforcement to come into play at a time when tolerance, in the form of increasing reward thresholds, appears to develop into positive reinforcement. Wise’s work has tended to focus on positive-reinforcement mechanisms that are important for establishing drug-seeking habits and reinstating them quickly after periods of abstinence, whereas Koob’s work has tended to focus on the negative-reinforcement mechanisms that become most obvious in the late stages of sustained addiction. While we tend to agree with each other about the early and late stages of addiction, we hold different views as to (i) the point between early and late at which the diagnosis of ‘addiction’ should be invoked, (ii) the relative importance of positive and negative reinforcement leading up to this transition, and (iii) the degree to which the specifics of negative reinforcement can be generalized across the range of addictive agents.
Topics: Animals; Behavior, Addictive; Brain; Humans; Reinforcement, Psychology; Substance-Related Disorders
PubMed: 24121188
DOI: 10.1038/npp.2013.261 -
Pain and Therapy Jun 2020Kratom, or Mitragyna, is a tropical plant indigenous to Southeast Asia, with unique pharmacological properties. It is commonly consumed by preparing the leaves into... (Review)
Review
Kratom, or Mitragyna, is a tropical plant indigenous to Southeast Asia, with unique pharmacological properties. It is commonly consumed by preparing the leaves into decoction or tea, or by grinding them into a powder. Recent evidence has revealed that kratom has physiological effects similar to opioids, including pain relief and euphoria, as well as stimulant properties, which together raise potential concern for dependence and addiction. Moreover, growing evidence suggests that the prevalence of kratom use is increasing in many parts of the world, raising important considerations for healthcare providers. This manuscript will discuss the most current epidemiology, pharmacology, toxicity, and management related to kratom, while seeking to provide a contemporary perspective on the issue and its role in the greater context of the opioid epidemic.
PubMed: 31994019
DOI: 10.1007/s40122-020-00151-x -
Journal of Thoracic Oncology : Official... Apr 2018The cannabis plant and its derivatives have been exploited for centuries for recreational and medicinal purposes, with millions of regular users around the world. The... (Review)
Review
The cannabis plant and its derivatives have been exploited for centuries for recreational and medicinal purposes, with millions of regular users around the world. The recreational use of cannabis is reflective of its neuropsychiatric effects, such as anxiolysis and euphoria. However, cannabis appears to have an emerging therapeutic role, especially in chronic disease and as an adjunct to cancer treatment. Increasing evidence supports cannabis in the management of chemotherapy-induced nausea and vomiting (CINV) and for pain management; however, studies are limited, particularly by difficulties associated with standardized dosing estimates and inability to accurately assess biologic activities of compounds in cannabis and derivative products. Smoking cannabis has not been proved to be a risk factor in the development of lung cancer, but the data are limited by small studies, misclassification due to self-reporting of use, small numbers of heavy cannabis smokers, and confounding of the risk associated with known causative agents for lung cancer (such as parallel chronic tobacco use). Cannabis and its biologically effective derivatives warrant additional research, ideally, controlled trials in which the cannabidiol and the delta-9-tetrahydrocabinol strength and use are controlled and documented.
Topics: Cannabis; Humans; Lung Neoplasms
PubMed: 29374567
DOI: 10.1016/j.jtho.2017.12.013 -
Neuropharmacology Jan 2023Mescaline (3,4,5-trimethoxyphenethylamine) is one of the oldest hallucinogens, with evidence of use dating back 5700 years. Mescaline is a naturally occurring alkaloid... (Review)
Review
INTRODUCTION
Mescaline (3,4,5-trimethoxyphenethylamine) is one of the oldest hallucinogens, with evidence of use dating back 5700 years. Mescaline is a naturally occurring alkaloid found in cacti, mainly in the peyote cactus (Lophophora williamsii) and in the cacti of the Echinopsis genus. Since the prohibition of psychoactive substances in the early 70s, research on mescaline and other classical psychedelics has been limited.
OBJECTIVES
This article aims to review the pharmacology and behavioural effects of mescaline, focusing on preclinical and clinical research.
FINDINGS
Mescaline is a serotonin 5HT2A/2C receptor agonist, with its main hallucinogenic effects being mediated via its 5HT2A receptor agonist action. It also exerts effects via agonist binding at α1A/2A noradrenaline and D1/2/3 dopamine receptors. Overall, mescaline has anxiolytic-like effects in animals and increases prosocial behaviour, locomotion, and response reactivity. In humans, mescaline can induce euphoria, hallucinations, improvements in well-being and mental health conditions, and psychotomimetic effects in a naturalistic or religious setting.
CONCLUSION
The pharmacological mechanisms of mescaline are similar to those of other classical psychedelics, like psilocybin and lysergic acid diethylamide (LSD). Mescaline appears to be safe to consume, with most intoxications being mild and easily treatable. Improvement in mental well-being and its ability to overcome alcoholism render mescaline potentially beneficial in clinical settings. This article is part of the Special Issue on 'Psilocybin Research'.
Topics: Animals; Humans; Mescaline; Hallucinogens; Psilocybin; Lysergic Acid Diethylamide; Serotonin 5-HT2 Receptor Agonists; Memory Disorders
PubMed: 36252614
DOI: 10.1016/j.neuropharm.2022.109294 -
F1000Research 2020Encephalitis is an important cause of morbidity, mortality, and permanent neurologic sequelae globally. Causes are diverse and include viral and non-viral infections... (Review)
Review
Encephalitis is an important cause of morbidity, mortality, and permanent neurologic sequelae globally. Causes are diverse and include viral and non-viral infections of the brain as well as autoimmune processes. In the West, the autoimmune encephalitides are now more common than any single infectious cause, but, in Asia, infectious causes are still more common. In 2006, the World Health Organization coined the term "acute encephalitis syndrome", which simply means acute onset of fever with convulsions or altered consciousness or both. In 2013, the International Encephalitis Consortium set criteria for diagnosis of encephalitis on basis of clinical and laboratory features. The most important infectious cause in the West is herpes simplex virus, but globally Japanese encephalitis (JE) remains the single largest cause. Etiologic diagnosis is difficult because of the large number of agents that can cause encephalitis. Also, the responsible virus may be detectable only in the brain and is either absent or transiently found in blood or cerebrospinal fluid (CSF). Virological diagnosis is complex, expensive, and time-consuming. Different centres could make their own algorithms for investigation in accordance with the local etiologic scenarios. Magnetic resonance imaging (MRI) and electroencephalography are specific for few agents. Clinically, severity may vary widely. A severe case may manifest with fever, convulsions, coma, neurologic deficits, and death. Autoimmune encephalitis (AIE) includes two major categories: (i) classic paraneoplastic limbic encephalitis (LE) with autoantibodies against intracellular neuronal antigens (Eg: Hu and Ma2) and (ii) new-type AIE with autoantibodies to neuronal surface or synaptic antigens (Eg: anti-N-methyl-D-aspartate receptor). AIE has prominent psychiatric manifestations: psychosis, aggression, mutism, memory loss, euphoria, or fear. Seizures, cognitive decline, coma, and abnormal movements are common. Symptoms may fluctuate rapidly. Treatment is largely supportive. Specific treatment is available for herpesvirus group and non-viral infections. Various forms of immunotherapy are used for AIE.
Topics: Acute Disease; Animals; Autoantibodies; Encephalitis; Hashimoto Disease; Humans; Receptors, N-Methyl-D-Aspartate
PubMed: 32047620
DOI: 10.12688/f1000research.20634.1 -
International Journal of Environmental... Dec 2019Pregnancy and lactation involve two aspects that are socially and culturally associated with women. However, there are a few biological differences between male and... (Review)
Review
Pregnancy and lactation involve two aspects that are socially and culturally associated with women. However, there are a few biological differences between male and female breast tissue. Lactation and pregnancy are viable processes that do not depend on sex. Even for the latter, it is only necessary to have an organ capable of gestation. Ways to favor mammogenesis and lactogenesis in trans* women have been established. There are protocols to promote lactation in trans* women, usually used for adoptive mothers or those whose children have been born through gestational surrogacy. Chestfeeding a baby could be the cause of feelings as diverse as gender dysphoria in the case of trans* men, and euphoria and affirmation of femininity in trans* women. This study involves a review of the available scientific literature addressing medical aspects related to pregnancy and lactation in trans* individuals, giving special attention to nursing care during perinatal care. There are scarce studies addressing care and specifically nursing care in trans* pregnancy and lactation. Our study indicates the factors that can be modified and the recommendations for optimizing the care provided to these individuals in order to promote and maintain the lactation period in search of improvement and satisfaction with the whole process.
Topics: Breast Feeding; Female; Gender Dysphoria; Humans; Lactation; Male; Mothers; Nursing; Parturition; Perinatal Care; Pregnancy; Transgender Persons
PubMed: 31861638
DOI: 10.3390/ijerph17010044