"La scienza è amica dell'etica". Questo blog analizza e commeneta le notizie scientifiche alle cui fonti si potrà accedere cliccando sul link sottolineato nel post. Per ricevere gli aggiornamenti del blog, iscriversi alla mailing list nell'apposita finestra.

Cannabis e psicosi

August 28th, 2016
Lancet. 2007 Jul 28;370(9584):319-28.

Cannabis use and risk of psychotic or affective mental health outcomes: a systematic review.

Abstract

BACKGROUND:

Whether cannabis can cause psychotic or affective symptoms that persist beyond transient intoxication is unclear. We systematically reviewed the evidence pertaining to cannabis use and occurrence of psychotic or affective mental health outcomes.

INTERPRETATION:

The evidence is consistent with the view that cannabis increases risk of psychotic outcomes independently of confounding and transient intoxication effects, although evidence for affective outcomes is less strong. The uncertainty about whether cannabis causes psychosis is unlikely to be resolved by further longitudinal studies such as those reviewed here. However, we conclude that there is now sufficient evidence to warn young people that using cannabis could increase their risk of developing a psychotic illness later in life.

Biol Psychiatry. 2016 Apr 1;79(7):e17-31. doi: 10.1016/j.biopsych.2015.11.013. Epub 2015 Dec 4.

The Role of Cannabinoids in Neuroanatomic Alterations in Cannabis Users.

Abstract

The past few decades have seen a marked change in the composition of commonly smoked cannabis. These changes primarily involve an increase of the psychoactive compound ∆(9)-tetrahydrocannabinol (THC) and a decrease of the potentially therapeutic compound cannabidiol (CBD). This altered composition of cannabis may be linked to persistent neuroanatomic alterations typically seen in regular cannabis users. In this review, we summarize recent findings from human structural neuroimaging investigations. We examine whether neuroanatomic alterations are 1) consistently observed in samples of regular cannabis users, particularly in cannabinoid receptor-high areas, which are vulnerable to the effects of high circulating levels of THC, and 2) associated either with greater levels of cannabis use (e.g., higher dosage, longer duration, and earlier age of onset) or with distinct cannabinoid compounds (i.e., THC and CBD). Across the 31 studies selected for inclusion in this review, neuroanatomic alterations emerged across regions that are high in cannabinoid receptors (i.e., hippocampus, prefrontal cortex, amygdala, cerebellum). Greater dose and earlier age of onset were associated with these alterations. Preliminary evidence shows that THC exacerbates, whereas CBD protects from, such harmful effects. Methodologic differences in the quantification of levels of cannabis use prevent accurate assessment of cannabisexposure and direct comparison of findings across studies. Consequently, the field lacks large “consortium-style” data sets that can be used to develop reliable neurobiological models of cannabis-related harm, recovery, and protection. To move the field forward, we encourage a coordinated approach and suggest the urgent development of consensus-based guidelines to accurately and comprehensively quantify cannabis use and exposure in human studies.

Danni da cannabis

August 28th, 2016
Curr Pharm Des. 2016 Aug 22. [Epub ahead of print]

Brain imaging studies on the cognitive, pharmacological and neurobiological effects of cannabis in humans: Evidence from studies of adult users.

Abstract

Cannabis is the most widely used illicit drug worldwide. Regular cannabis use has been associated with a range of acute and chronic mental health problems, such as anxiety, depression, psychotic symptoms and neurocognitive impairments and their neural mechanisms need to be examined. This review summarizes and critically evaluates brain-imaging studies of cannabis in recreational and regular cannabis users between January 2000 and January 2016. The search has yielded eligible 103 structural and functional studies. Regular use of cannabis results in volumetric, gray matter and white matter structural changes in the brain, in particular in the hippocampus and the amygdala. Regular use ofcannabis affects cognitive processes such as attention, memory, inhibitory control, decision-making, emotional processing, social cognition and their associated brain areas. There is evidence that regular cannabis use leads to altered neural function during attention and working memory and that recruitment of activity in additional brain regions can compensate for it. Similar to other drugs of abuse, cannabis cues activated areas in the reward pathway. Pharmacological studies showed a modest increase in human striatal dopamine transmission after administration of THC in healthy volunteers. Regular cannabis use resulted in reduced dopamine transporter occupancy and reduced dopamine synthesis but not in reduced striatal D2/D3 receptor occupancy compared with healthy control participants. Studies also showed different effects of Δ-9 tetrahydrocannabinol (THC) and cannabidiol (CBD) on emotion, cognition and associated brain regions in healthy volunteers, whereby CBD protects against the psychoactive effects of THC. Brain imaging studies using selective high-affinity radioligands for the imaging of cannabinoid CB1 receptor availability in Positron Emission Tomography (PET) showed downregulation of CB1 in regular users of cannabis. In conclusion, regular use of the cannabinoids exerts structural and functional changes in the human brain. These changes have profound implications for our understanding of the neuropharmacology of cannabis and its effects on cognition, mental health and the brain.

La cannabis non è innocua: in questi articoli si descrive con dovizia di particolare i danni registrati con la risonanza magnetica, in particolare sugli adolescenti.

Sex Effects of Marijuana on Brain Structure and Function. Ketcherside A, Baine J, Filbey F. Curr Addict Rep. 2016;3:323-331. Epub 2016 Jul 7. Review

Trajectories of cannabis use disorder: risk factors, clinical characteristics, and outcomes. Kosty DB, Seeley JR, Farmer RF, Stevens JJ, Lewinsohn PM. Addiction. 2016 Aug 12. doi: 10.1111/add.13557. [Epub ahead of print]

Adolescent cannabis use: What is the evidence for functional brain alteration? Solowij N. Curr Pharm Des. 2016 Aug 5. [Epub ahead of print]

Jakabek D, Yücel M, Lorenzetti V, Solowij N. Psychopharmacology (Berl). 2016 Aug 8. [Epub ahead of print]

Dolore dei bambini

August 19th, 2016
Carlo Valerio Bellieni, Monica Tei, Giuseppe Buonocore

Abstract

Neonatal pain treatment requires personalization, and pain assessment should be contextualized to be effective. Here we summarize the available tools in neonatal analgesia, paying a special attention to highlight the personalization of antalgic behavior, both in assessment and in treatment of neonatal pain.

Apprendimento prima di nascere

August 19th, 2016
J Voice. 2016 Jul 7. pii: S0892-1997(16)30124-2. doi: 10.1016/j.jvoice.2016.06.009. [Epub ahead of print]

Fundamental Frequency Variation in Crying of Mandarin and German Neonates.

I neonati piangono con tonalità differente a seconda della voce materna che hanno sentito prima di nascere

Olio di palma

July 28th, 2016

Piantiamola col dire cose inesatte e spaventare la gente… Ecco come stanno davvero le cose.

Cannabis medica: tutto ok?

July 28th, 2016
Drug Alcohol Depend. 2016 Jul 18. pii: S0376-8716(16)30163-6.

Medical marijuana legalization and cigarette and marijuana co-use in adolescents and adults.

Lo studio fatto sui dati nazionali USA mostra che la dispponibiità della “cannabis terapeutica” comporta un increment di uso non solo della cannabis ricreazionale, ma anche del fumo di tabacco. d’altronde, se passa il concetto che “nulla fa male basta crederci”…

Rev Med Inst Mex Seguro Soc. 2016 Sep-Oct;54(5):626-34.

[Cannabis: Effects in the Central Nervous System. Therapeutic, societal and legal consequences].

Un articolo di sintesi sulla letteratura scientifica, che mostra i danni della cannabis sul cervello, e in particolare sembra che mentre una sostanza derivata dalla cannabis possa avere effetti positivi contro il dolore nei pazienti con sclerosi multipla, ne peggiorerebbe il livello cognitivo.

Danni da cannabis

July 26th, 2016
Pharmacol Res. 2016 Jul 12;111:459-470. doi: 10.1016/j.phrs.2016.07.008. [Epub ahead of print]

Long-term hippocampal glutamate synapse and astrocyte dysfunctions underlying the altered phenotype induced by adolescent THC treatment in male rats.

Somministrando cannabis ai ratti durante la loro adolescenza, si provocano alterazioni del comportamento, della memoria e dell’atteggiamento nei rapporti con gli altri anche a lunga distanza di tempo.

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