The International Cannabis Toolkit (iCannToolkit): a multidisciplinary expert consensus on minimum standards for measuring cannabis use

Background: The lack of an agreed international minimum approach to measuring cannabis use hinders the integration of multidisciplinary evidence on the psychosocial, neurocognitive, clinical and public health consequences of cannabis use. Methods: A group of 25 international expert cannabis researchers convened to discuss a multidisciplinary framework for minimum standards to measure cannabis use globally in diverse settings. Results: The expert-based consensus agreed upon a three-layered hierarchical framework. Each layer—universal measures, detailed self-report and biological measures—reflected different research priorities and minimum standards, costs and ease of implementation. Additional work is needed to develop valid and precise assessments. Conclusions: Consistent use of the proposed framework across research, public health, clinical practice and medical settings would facilitate harmonisation of international evidence on cannabis consumption, related harms and approaches to their mitigation

Associations between regular cannabis use and brain resting-state functional connectivity in adolescents and adults

BACKGROUND/AIM: Cannabis use is highly prevalent in adolescents; however, little is known about its effects on adolescent brain function. METHOD: Resting-state functional magnetic resonance imaging was used in matched groups of regular cannabis users (N = 70, 35 adolescents: 16-17 years old, 35 adults: 26-29 years old) and non-regular-using controls (N = 70, 35 adolescents/35 adults). Pre-registered analyses examined the connectivity of seven major cortical and sub-cortical brain networks (default mode network, executive control network (ECN), salience network, hippocampal network and three striatal networks) using seed-based analysis methods with cross-sectional comparisons between user groups and age groups. RESULTS: The regular cannabis use group (across both age groups), relative to controls, showed localised increases in connectivity only in the ECN analysis. All networks showed localised connectivity differences based on age group, with the adolescents generally showing weaker connectivity than adults, consistent with the developmental effects. Mean connectivity across entire network regions of interest (ROIs) was also significantly decreased in the ECN in adolescents. However, there were no significant interactions found between age group and user group in any of the seed-based or ROI analyses. There were also no associations found between cannabis use frequency and any of the derived connectivity measures. CONCLUSION: Regular cannabis use is associated with changes in connectivity of the ECN, which may reflect allostatic or compensatory changes in response to regular cannabis intoxication. However, these associations were not significantly different in adolescents compared to adults

Anhedonia, apathy, pleasure, and effort-based decision-making in adult and adolescent cannabis users and controls

BACKGROUND: Cannabis use may be linked with anhedonia and apathy. However, previous studies have shown mixed results and few have examined the association between cannabis use and specific reward sub-processes. Adolescents may be more vulnerable to harmful effects of cannabis than adults. This study investigated (1) the association between non-acute cannabis use and apathy, anhedonia, pleasure, and effort-based decision-making for reward, and (2) whether these relationships were moderated by age-group. METHODS: We used data from the 'CannTeen' study. Participants were 274 adult (26-29 years) and adolescent (16-17 years) cannabis users (1-7 days/week use in the past three months), and gender- and age-matched controls. Anhedonia was measured with the Snaith-Hamilton Pleasure Scale (n=274), and apathy was measured with the Apathy Evaluation Scale (n=215). Effort-based decision-making for reward was measured with the Physical Effort task (n=139), and subjective wanting and liking of rewards was measured with the novel Real Reward Pleasure task (n=137). RESULTS: Controls had higher levels of anhedonia than cannabis users (F1,258=5.35, p=.02, ηp2=.02). There were no other significant effects of User-Group and no significant User-Group*Age-Group interactions. Null findings were supported by post hoc Bayesian analyses. CONCLUSION: Our results suggest that cannabis use at a frequency of three to four days per week is not associated with apathy, effort-based decision-making for reward, reward wanting, or reward liking in adults or adolescents. Cannabis users had lower anhedonia than controls, albeit at a small effect size. These findings are not consistent with the hypothesis that non-acute cannabis use is associated with amotivation

The International Cannabis Toolkit (iCannToolkit) : A multidisciplinary expert consensus on minimum standards for measuring cannabis use

Background The lack of an agreed international minimum approach to measuring cannabis use hinders the integration of multidisciplinary evidence on the psychosocial, neurocognitive, clinical and public health consequences of cannabis use. Methods A group of 25 international expert cannabis researchers convened to discuss a multidisciplinary framework for minimum standards to measure cannabis use globally in diverse settings. Results The expert-based consensus agreed upon a three-layered hierarchical framework. Each layer—universal measures, detailed self-report and biological measures—reflected different research priorities and minimum standards, costs and ease of implementation. Additional work is needed to develop valid and precise assessments. Conclusions Consistent use of the proposed framework across research, public health, clinical practice and medical settings would facilitate harmonisation of international evidence on cannabis consumption, related harms and approaches to their mitigation

Search for the standard model Higgs boson produced in association with W and Z bosons in pp collisions at √s=7 TeV

This is the pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 Springer Verlag.A search for the Higgs boson produced in association with a W or Z boson in proton-proton collisions at a center-of-mass energy of 7 TeV is performed with the CMS detector at the LHC using the full 2011 data sample, from an integrated luminosity of 5 fb−1. Higgs boson decay modes to ττ and WW are explored by selecting events with three or four leptons in the final state. No excess above background expectations is observed, resulting in exclusion limits on the product of Higgs associated production cross section and decay branching fraction for Higgs boson masses between 110 and 200 GeV in these channels. Combining these results with other CMS associated production searches using the same dataset in the H→ γγ and H→ bb− decay modes, the cross section for associated Higgs boson production 3.3 times the standard model expectation or larger is ruled out at the 95% confidence level for a Higgs boson mass of 125 GeV.This study is funded by the BMWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); MoER, SF0690030s09 and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); MSI (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MON, RosAtom, RAS and RFBR (Russia); MSTD (Serbia); SEIDI and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); ThEP, IPST and NECTEC (Thailand); TUBITAK and TAEK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (USA)

Search for the standard model Higgs boson produced in association with W and Z bosons in pp collisions at root s=7 TeV

A search for the Higgs boson produced in association with a W or Z boson in proton-proton collisions at a center-of-mass energy of 7 TeV is performed with the CMS detector at the LHC using the full 2011 data sample, from an integrated luminosity of 5 fb−1. Higgs boson decay modes to ττ and WW are explored by selecting events with three or four leptons in the final state. No excess above background expectations is observed, resulting in exclusion limits on the product of Higgs associated production cross section and decay branching fraction for Higgs boson masses between 110 and 200 GeV in these channels. Combining these results with other CMS associated production searches using the same dataset in the H→ γγ and H→ b b¯ decay modes, the cross section for associated Higgs boson production 3.3 times the standard model expectation or larger is ruled out at the 95% confidence level for a Higgs boson mass of 125 GeV

Neural responses to reward anticipation and feedback in adult and adolescent cannabis users and controls.

Funder: Aker FoundationFunder: Wallitt Foundation, Eton CollegeChronic use of drugs may alter the brain's reward system, though the extant literature concerning long-term cannabis use and neural correlates of reward processing has shown mixed results. Adolescents may be more vulnerable to the adverse effects of cannabis than adults; however, this has not been investigated for reward processing. As part of the 'CannTeen' study, in the largest functional magnetic resonance imaging study of reward processing and cannabis use to date, we investigated reward anticipation and feedback in 125 adult (26-29 years) and adolescent (16-17 years) cannabis users (1-7 days/week cannabis use) and gender- and age-matched controls, using the Monetary Incentive Delay task. Blood-oxygen-level-dependent responses were examined using region of interest (ROI) analyses in the bilateral ventral striatum for reward anticipation and right ventral striatum and left ventromedial prefrontal cortex for feedback, and exploratory whole-brain analyses. Results showed no User-Group or User-Group × Age-Group effects during reward anticipation or feedback in pre-defined ROIs. These null findings were supported by post hoc Bayesian analyses. However, in the whole-brain analysis, cannabis users had greater feedback activity in the prefrontal and inferior parietal cortex compared to controls. In conclusion, cannabis users and controls had similar neural responses during reward anticipation and in hypothesised reward-related regions during reward feedback. The whole-brain analysis revealed tentative evidence of greater fronto-parietal activity in cannabis users during feedback. Adolescents showed no increased vulnerability compared with adults. Overall, reward anticipation and feedback processing appear spared in adolescent and adult cannabis users, but future longitudinal studies are needed to corroborate this