Dialogues in Clinical Neuroscience最新文献

Cannabis can elicit an acute psychotic reaction, and its long-term use is a risk factor for schizophrenia. The main active psychoactive ingredient ∆⁹-tetrahydrocannabinol (Δ⁹-THC) activates cannabinoid 1 (CB1) receptors, which are localized to the terminals of glutamate and GABA neurons in the brain. The endogenous cannabinoids are involved in information processing and plasticity at synapses in the hippocampus, basal ganglia, and cerebral cortex. Exogenously applied CB₁ receptor agonists disrupt neuronal dynamics and synaptic plasticity, resulting in cognitive deficits and impairment of the highest psychological functions. Various other pro-psychotic drugs, such as ketamine and methamphetamine, exert their effects in the same microdomain of synaptic spines as Δ⁹-THC. Additionally, many of the most robust findings in psychiatric genetics include components that localize to dendritic spines and have important roles in information processing and plasticity.
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Mental disorders represent a significant public health burden worldwide due to their high prevalence, chronically disabling nature, and substantial impact on quality of life. Despite growing knowledge of the pathological mechanisms that underlie the development of these disorders, a high percentage of patients do not respond to first-line clinical treatments; thus, there is a strong need for alternative therapeutic approaches. During the past half-century, after the identification of the endocannabinoid system and its role in multiple physiological processes, both natural and synthetic cannabinoids have attracted considerable interest as putative medications in pathological conditions such as, but not exclusive to, mental disorders. Here, we provide a summary of cannabinoid effects in support of possible therapeutic applications for major depression, bipolar disorder, anxiety, posttraumatic stress disorder, and schizophrenia. Considering this evidence, highlighted benefits and risks of cannabinoid use in the management of these illnesses require further experimental study.
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As is the case for most drugs, cannabis use has costs and benefits, and so do the policies that attempt to minimize the first and maximize the second. This article summarizes what we know about the harmful effects of recreational cannabis use and the benefits of medical cannabis use under the policy of prohibition that prevailed in developed countries until 2012. It outlines three broad ways in which cannabis prohibition may be relaxed, namely, the depenalization of personal possession and use, the legalization of medical use, and the legalization of adult recreational use. It reviews evidence to date on the impacts of each of these forms of liberalization on the costs and benefits of cannabis use. It makes some plausible conjectures about the future impacts of the commercialization of cannabis using experience from the commercialization of the alcohol, tobacco, and gambling industries. Cannabis policy entails unavoidable trade-offs between competing social values in the face of considerable uncertainty about the effects that more liberal cannabis policies will have on cannabis use and its consequences for better or worse.
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This brief report covers recent advances in cannabis and cannabinoid regulation and drug approval. The popularity of cannabis and cannabinoid products continues to rise, and these products are available for the majority of the population in the United States to purchase as easily as alcohol. Although many states have approved programs and research licenses, these activities and products all remain federally illegal. The solution may be for the United States to offer multiple pathways for product approval that adapt to the diversity of the products and the needs of the consumer. Multiple pathways for market approval would protect public health, whether the public is using cannabis and cannabinoids as a medicine, a wellness product, or as a recreational substance.
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The endocannabinoid system is widely expressed in the limbic system, prefrontal cortical areas, and brain structures regulating neuroendocrine stress responses, which explains the key role of this system in the control of emotions. In this review, we update recent advances on the function of the endocannabinoid system in determining the value of fear-evoking stimuli and promoting appropriate behavioral responses for stress resilience. We also review the alterations in the activity of the endocannabinoid system during fear, stress, and anxiety, and the pathophysiological role of each component of this system in the control of these protective emotional responses that also trigger pathological emotional disorders. In spite of all the evidence, we have not yet taken advantage of the therapeutic implications of this important role of the endocannabinoid system, and possible future strategies to improve the treatment of these emotional disorders are discussed.
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The endocannabinoid (eCB) system encompasses the eCBs anandamide and 2-arachidonoylglycerol, their anabolic/catabolic enzymes, and the cannabinoid CB₁ and CB₂ receptors. Its expansion to include several eCB-like lipid mediators, their metabolic enzymes, and their molecular targets, forms the endocannabinoidome (eCBome). This complex signaling system is deeply involved in the onset, progress, and symptoms of major neuropsychiatric disorders and provides a substrate for future therapeutic drugs against these diseases. Such drugs may include not only THC, the major psychotropic component of cannabis, but also other, noneuphoric plant cannabinoids. These compounds, unlike THC, possess a wide therapeutic window, possibly due to their capability of hitting several eCBome and non-eCBome receptors. This is particularly true for cannabidiol, which is one of the most studied cannabinoids and shows promise for the treatment of a wide range of mental and mood disorders. The eCBome plays a role also in the microbiota-gut-brain axis, which is emerging as an important actor in the control of affective and cognitive functions and in their pathological alterations.
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Chemsex is an escalating public health issue among men who have sex with men, with potentially severe somatic and psychiatric consequences. Given the limited knowledge and lack of treatment recommendations available in this area, we proposed the use of noninvasive brain stimulation in order to reduce problematic chemsex behavior. This is the first open-label case report of a positive effect of transcranial direct current stimulation (tDCS) in a patient who was complaining of severe chemsex addiction. Total disappearance of chemsex behavior occurred after 5 days of daily sessions of right prefrontal cortex stimulation and did not return after 8 months of follow-up. The strengthening of dorsolateral prefrontal cortex activity may have modulated limbic pathways and reduced incentive salience and craving of both sexual addiction and concomitant illicit drug use.
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Adolescents are constantly connected to their devices, and concerns have been raised that this connectivity is damaging their development more generally, and their mental health in particular. Recent narrative reviews and meta-analyses do not support a strong linkage between the quantity of adolescents' digital technology engagement and mental health problems. Instead, it appears that offline vulnerabilities tend to mirror and shape online risks in ways that may further amplify mental health inequalities among youth. New approaches for supporting youth mental health, especially for vulnerable youth and those typically excluded from traditional services, are now both possible and required.
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The growing amount of screen time among adolescents has raised concerns about the effects it may have on their physical and psychological health. Although the literature is divided on whether the effects are mostly positive, neutral, or mostly negative, it is likely that the impacts will be highly individualized with a mixture of good and bad consequences for each person. Understanding behavioral and neurobiological phenomena of adolescence may help to guide research and interventions to optimize the benefits and minimize the risks. Particular aspects of adolescent development relevant to the issue include: (i) hunger for human connectedness; (ii) appetite for adventure; and (iii) desire for data.
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This overview will outline the current results of neuroscience research on the possible effects of digital media use on the human brain, cognition, and behavior. This is of importance due to the significant amount of time that individuals spend using digital media. Despite several positive aspects of digital media, which include the capability to effortlessly communicate with peers, even over a long distance, and their being used as training tools for students and the elderly, detrimental effects on our brains and minds have also been suggested. Neurological consequences have been observed related to internet/gaming addiction, language development, and processing of emotional signals. However, given that much of the neuroscientific research conducted up to now relies solely on self-reported parameters to assess social media usage, it is argued that neuroscientists need to include datasets with higher precision in terms of what is done on screens, for how long, and at what age.
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