25 research outputs found

    Making sense: dopamine activates conscious self-monitoring through medial prefrontal cortex

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    When experiences become meaningful to the self, they are linked to synchronous activity in a paralimbic network of self-awareness and dopaminergic activity. This network includes medial prefrontal and medial parietal/posterior cingulate cortices, where transcranial magnetic stimulation may transiently impair self-awareness. Conversely, we hypothesize that dopaminergic stimulation may improve self-awareness and metacognition (i.e., the ability of the brain to consciously monitor its own cognitive processes). Here, we demonstrate improved noetic (conscious) metacognition by oral administration of 100 mg dopamine in minimal self-awareness. In a separate experiment with extended self-awareness dopamine improved the retrieval accuracy of memories of self-judgment (autonoetic, i.e., explicitly self-conscious) metacognition. Concomitantly, magnetoencephalography (MEG) showed increased amplitudes of oscillations (power) preferentially in the medial prefrontal cortex. Given that electromagnetic activity in this region is instrumental in self-awareness, this explains the specific effect of dopamine on explicit self-awareness and autonoetic metacognition

    Impulsivity traits and addiction-related behaviors in youth.

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    Background and aims Impulsivity is a risk factor for addictive behaviors. The UPPS-P impulsivity model has been associated with substance addiction and gambling disorder, but its role in other non-substance addiction-related behaviors is less understood. We sought to examine associations between UPPS-P impulsivity traits and indicators of multiple substance and non-substance addiction-related behaviors in youth with varying involvement in these behaviors. Methods Participants (N = 109, aged 16-26 years, 69% males) were selected from a national survey based on their level of externalizing problems to achieve a broad distribution of involvement in addiction-related behaviors. Participants completed the UPPS-P Questionnaire and standardized questionnaires assessing problematic use of substances (alcohol, cannabis, and other drugs) and non-substances (Internet gaming, pornography, and food). Regression analyses were used to assess associations between impulsivity traits and indicators of addiction-related behaviors. Results The UPPS-P model was positively associated with indicators of all addiction-related behaviors except problematic Internet gaming. In the fully adjusted models, sensation seeking and lack of perseverance were associated with problematic use of alcohol, urgency was associated with problematic use of cannabis, and lack of perseverance was associated with problematic use of other drugs than cannabis. Furthermore, urgency and lack of perseverance were associated with binge eating and lack of perseverance was associated with problematic use of pornography. Discussion and conclusions We emphasize the role of trait impulsivity across multiple addiction-related behaviors. Our findings in at-risk youth highlight urgency and lack of perseverance as potential predictors for the development of addictions and as potential preventative therapeutic targets.The project was supported by Aarhus University Research Foundation (AUFF), Assistant Professor Starting Grant - R46-A4016 (K.R.T., M.B.C., V.V., M.U.P.); Danish Ministry for Social Affairs and the Interior - 9173-0003 (K.R.T., M.B.C., M.U.P., M.M.P., T.L.K.); and Medical Research Council (MRC), Senior Clinical Fellowship - MR/P008747/1 (V.V.)

    Changes in the composition of cannabis from 2000-2017 in Denmark:Analysis of confiscated samples of cannabis resin

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    Globally, recent studies report increases in Δ-9-tetrahydrocannabinol (THC) concentration in seized samples of cannabis for human consumption. This is important, because use of cannabis with a high concentration of THC has been linked to a number of adverse health outcomes. The objective of this study was to assess recent changes in the composition of seized cannabis resin in Denmark by (a) examining THC concentration in samples from Danish forensic laboratories from 2000 to 2017 ( N = 430) and (b) examining cannabidiol (CBD) concentration and the THC:CBD concentration ratio in samples from the forensic laboratory in Western Denmark from 2008 to 2017 ( N = 147). Cannabis resin samples were analyzed using a gas chromatographic analysis with flame ionization detection quantifying the total THC and CBD concentration. Results showed that the THC concentration increased 3-fold from 2000 (mean: 8.3%) to 2017 (mean: 25.3%). Significant increases occurred in all areas of Denmark. After 2011, we found a dramatic increase in cannabis resin samples with high THC concentration and the near disappearance of cannabis resin samples with medium- and low THC concentration. Furthermore, the THC:CBD concentration ratio increased significantly from 1.4 in 2008 to 4.4 in 2017. Whereas THC concentration increased, CBD concentration remained stable at ∼6%. In conclusion, the THC concentration of cannabis resin, and THC:CBD concentration ratio, have increased dramatically in Denmark, potentially leading to higher risk of harm to users. Policymakers, treatment professionals, and educators should be aware of this change. (PsycINFO Database Record (c) 2019 APA, all rights reserved). </p
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