41 research outputs found

    Review: The Efficacy of Cannabidiol (CBD) as Potential Antipsychotic Medication

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    Psychotic disorders such as schizophrenia are widespread and severely disabling; however, current pharmacological treatments are unsatisfactory due to major side effects. The current review discusses the therapeutic potential of cannabidiol (CBD), a non-psychoactive component of cannabis, as an antipsychotic drug. Research lines including studies based on animal models of psychosis, human experimental studies, neuroimaging studies, epidemiological studies, and clinical studies are reviewed. The studies described provide empirical support for the antipsychotic effects of CBD and indicate reduced side effects, high tolerability, and superior cost-effectiveness compared to regular antipsychotic medication. It is concluded that CBD may prove a safe and attractive alternative treatment for psychotic conditions. However, current evidence largely stems from experimental, non-clinical studies. Large-scale randomized clinical trials are needed before this can be implemented in practice

    The importance of the smallest effect size of interest in expert witness testimony on alcohol and memory

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    Memory experts are sometimes asked to evaluate the validity of accounts of witnesses, victims, or suspects. In some of these cases, they are asked what effect alcohol has on the validity of such accounts. In this article, we offer a guide on what expert witnesses can reliably say about how alcohol affects memory. We do so by resorting to effect sizes from previous studies and meta-analytic work, and address this novel question: Are these effect sizes meaningful in legal cases? More specifically, we argue that any determination of whether individual studies about alcohol and memory are practically relevant for legal cases, scientists must focus on the smallest effect size of interest. We make the case that a decrease or increase of only 1 detail, especially an incorrect detail, should be regarded as the smallest effect size of interest in this line of research. In line with this idea, we show that effect sizes in the alcohol and memory literature are often larger than this smallest effect size of interest. This finding is important because it implies that alcohol often exerts a practically relevant and meaningful detrimental effect on the reporting of both correct and incorrect details, which in turn negatively affects the validity of witness testimony

    Cortical structural differences following repeated ayahuasca use hold molecular signatures

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    IntroductionSerotonergic psychedelics such as ayahuasca are reported to promote both structural and functional neural plasticity via partial 5-HT2A agonism. However, little is known about how these molecular mechanisms may extend to repeated psychedelic administration in humans, let alone neuroanatomy. While early evidence suggests localised changes to cortical thickness in long-term ayahuasca users, it is unknown how such findings may be reflected by large-scale anatomical brain networks comprising cytoarchitecturally complex regions.MethodsHere, we examined the relationship between cortical gene expression markers of psychedelic action and brain morphometric change following repeated ayahuasca usage, using high-field 7 Tesla neuroimaging data derived from 24 members of an ayahuasca-using church (Santo Daime) and case-matched controls.ResultsUsing a morphometric similarity network (MSN) analysis, repeated ayahuasca use was associated with a spatially distributed cortical patterning of both structural differentiation in sensorimotor areas and de-differentiation in transmodal areas. Cortical MSN remodelling was found to be spatially correlated with dysregulation of 5-HT2A gene expression as well as a broader set of genes encoding target receptors pertinent to ayahuasca’s effects. Furthermore, these associations were similarly interrelated with altered gene expression of specific transcriptional factors and immediate early genes previously identified in preclinical assays as relevant to psychedelic-induced neuroplasticity.ConclusionTaken together, these findings provide preliminary evidence that the molecular mechanisms of psychedelic action may scale up to a macroscale level of brain organisation in vivo. Closer attention to the role of cortical transcriptomics in structural-functional coupling may help account for the behavioural differences observed in experienced psychedelic users

    Hazy memories: the impact of drugs on false memory formation from a legal-psychopharmacological perspective

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    In many criminal cases, no physical evidence is available, so that legal decision-making has to rely strongly on the testimonies of witnesses, victims, and suspects. However, individuals involved in crime are often intoxicated with drugs, such as alcohol, cannabis, or MDMA (ecstasy). These drugs have long been known to interfere with memory by increasing forgetfulness, but there is little knowledge about whether they also heighten the occurrence of false memories – so remembering events or details that did not happen. Across one literature review and four experimental studies, it was assessed whether drug intoxication, especially with cannabis and MDMA, can increase the susceptibility to false memories. Cannabis use was consistently linked to higher false memories, especially during acute intoxication, which has important implications for legal, forensic, and clinical settings. MDMA intoxication was found to increase forgetting but did not heighten false memories. In sum, the thesis concluded that a nuanced approach is needed when dealing with intoxicated persons in the legal system, because differences between drugs exist in how memory for a crime is affected

    Cannabis increases susceptibility to false memory.

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    Hazy memories: Cannabis increases susceptibility to false memory

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    Placebo-controlled study investigating the immediate and delayed effects of cannabis on false memory formatio

    Lowlands field study

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    False memory in cannabis users: materials

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    This study examined the impact of cannabis use on false memory production. The Deese/Roediger-McDermott (DRM) paradigm was used to induce false memories. In this paradigm, participants study word lists that are associatively related to a non-presented word, termed the critical lure. In a later memory test, true recognition rates and false alarm rates toward critical lures and unrelated items are assessed. Memory performance was compared between three groups: Regular cannabis consumers who were acutely intoxicated (n=53), regular cannabis consumers who were sober (n=50), and cannabis-naïve participants (n=53). The participants were approached in Dutch coffeeshops (cannabis outlets) and cafes and asked to participate in our study. After collecting general information on their cannabis use, they were subjected to the DRM test. The materials for the DRM paradigm and the questionnaires used can be found in this folder

    Highwitness Online Study

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    Background: Acute cannabis intoxication has recently been associated with heightened risk of forming false memories (remembering events that never happened), which can have severe implications for legal settings, such as when eyewitnesses are questioned about a criminal event. However, no evidence-based interview protocol has been tested in the population of cannabis users. This study aims to test whether sober vs. intoxicated cannabis users vs. non-users can provide accurate eyewitness testimony when interviewed with a modified version of the Cognitive Interview. Timing of the intoxication will also be varied (intoxicated during encoding and retrieval vs. intoxicated during retrieval only). Study population: Regular cannabis users (3 groups) and non-users (1 group). Inclusion criteria: Aged 18-40 years; Written Informed Consent; Passes the screening questions Exclusion criteria: Failing one of the screening questions; impaired vision, alcohol consumption on the day of testing Main study parameters/endpoints: Independent: cannabis user status (user vs. non-user), intoxication status (intoxicated vs. sober), intoxication timing (at encoding + retrieval vs. at retrieval only). Dependent: Memory performance on the Sketch Cognitive Interview (completeness, accuracy, confabulations, measures of meta-cognition), lineup performance Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Participants will view a video of a crime taking place (i.e., theft), followed by a filler task (copying simple drawings shown on a screen) and a questionnaire regarding their drug use history and demographics. Subsequently, they will be interviewed about what they saw to assess their memory of the event using the modified (sketch) Cognitive Interview (CI; Dando et al., 2011). Lastly, the participants will be shown three target-absent line-ups, in which they are asked to identify the two perpetrators and victim
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