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Macleod E, Heffernan T, Greenwood LM, Walker I, Lane J, Stanley SK, Evans O, Calear AL, Cruwys T, Christensen BK, Kurz T, Lancsar E, Reynolds J, Rodney Harris R, Sutherland S. Predictors of individual mental health and psychological resilience after Australia's 2019-2020 bushfires. Aust N Z J Psychiatry 2024; 58:58-69. [PMID: 37264605 PMCID: PMC10756019 DOI: 10.1177/00048674231175618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
AIMS We assessed the mental health effects of Australia's 2019-2020 bushfires 12-18 months later, predicting psychological distress and positive psychological outcomes from bushfire exposure and a range of demographic variables, and seeking insights to enhance disaster preparedness and resilience planning for different profiles of people. METHODS We surveyed 3083 bushfire-affected and non-affected Australian residents about their experiences of bushfire, COVID-19, psychological distress (depression, anxiety, stress, post-traumatic stress disorder) and positive psychological outcomes (resilient coping, wellbeing). RESULTS We found high rates of distress across all participants, exacerbated by severity of bushfire exposure. For people who were bushfire-affected, being older, having less financial stress, and having no or fewer pre-existing mental disorders predicted both lower distress and higher positive outcomes. Being male or having less income loss also predicted positive outcomes. Severity of exposure, higher education and higher COVID-19-related stressors predicted both higher distress and higher positive outcomes. Pre-existing physical health diagnosis and previous bushfire experience did not significantly predict distress or positive outcomes. RECOMMENDATIONS To promote disaster resilience, we recommend investment in mental health, particularly for younger adults and for those in rural and remote areas. We also recommend investment in mechanisms to protect against financial distress and the development of a broader definition of bushfire-related impacts than is currently used to capture brushfires' far-reaching effects.
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Affiliation(s)
- Emily Macleod
- School of Medicine and Psychology, The Australian National University, Canberra, ACT, Australia
- Centre for Mental Health Research, The Australian National University, Canberra, ACT, Australia
| | - Timothy Heffernan
- School of Medicine and Psychology, The Australian National University, Canberra, ACT, Australia
- School of Built Environment, University of New South Wales, Sydney, NSW, Australia
| | - Lisa-Marie Greenwood
- School of Medicine and Psychology, The Australian National University, Canberra, ACT, Australia
| | - Iain Walker
- School of Medicine and Psychology, The Australian National University, Canberra, ACT, Australia
- Melbourne Centre for Behaviour Change, The University of Melbourne, Parkville, VIC, Australia
| | - Jo Lane
- National Centre for Epidemiology and Population Health, The Australian National University, Canberra, ACT, Australia
| | - Samantha K Stanley
- School of Medicine and Psychology, The Australian National University, Canberra, ACT, Australia
| | - Olivia Evans
- School of Medicine and Psychology, The Australian National University, Canberra, ACT, Australia
| | - Alison L Calear
- Centre for Mental Health Research, The Australian National University, Canberra, ACT, Australia
| | - Tegan Cruwys
- School of Medicine and Psychology, The Australian National University, Canberra, ACT, Australia
| | - Bruce K Christensen
- School of Medicine and Psychology, The Australian National University, Canberra, ACT, Australia
| | - Tim Kurz
- School of Psychological Science, The University of Western Australia, Perth, WA, Australia
| | - Emily Lancsar
- Centre for Mental Health Research, The Australian National University, Canberra, ACT, Australia
| | - Julia Reynolds
- School of Medicine and Psychology, The Australian National University, Canberra, ACT, Australia
| | - Rachael Rodney Harris
- Centre for Entrepreneurial Agri-Technology, The Australian National University, Canberra, ACT, Australia
| | - Stewart Sutherland
- School of Medicine and Psychology, The Australian National University, Canberra, ACT, Australia
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2
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Bartschi JG, Greenwood LM. Food addiction as a mediator between depressive symptom severity and body mass index. Appetite 2023; 190:107008. [PMID: 37625647 DOI: 10.1016/j.appet.2023.107008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 07/15/2023] [Accepted: 08/19/2023] [Indexed: 08/27/2023]
Abstract
Depression is associated with an increased risk of cardiometabolic disease linked to weight gain driven by complex interactions between multiple risk factors, including overeating behaviours. However, risk factors that mediate the relationship between depressive symptoms and weight gain remain to be fully elucidated. This study examined food addiction symptoms as a potential mediator on the relationship between depressive symptom severity and adiposity as measured by body mass index (BMI), and evaluated whether this relationship was contingent on appetite symptom profile and sex. In a sample of 628 adults, depressive symptom severity was assessed using the Centre for Epidemiological Studies Depression Scale (CES-D), and food addiction symptoms were measured using the Yale Food Addiction Scale (YFAS, version 2). Participant demographics, including BMI, appetite presentations and sex, were assessed using self-report questions. Mediation and moderated mediation analyses were performed to determine relationships between variables. The prevalence of depressogenic food addiction in the present sample was 21.7%. After accounting for age and averaged amount of exercise, food addiction symptoms fully mediated the relationship between depressive symptom severity and BMI. Appetite symptom profile was a significant moderator of this relationship, with effects more pronounced in those with increased appetite compared to decreased or unchanged appetite. While sex was not a significant moderator, being male or female was associated with higher food addiction scores. This study supports food addiction symptoms as an important behavioural risk factor for increased adiposity linked to greater depressive symptom severity, particularly in those experiencing increased appetite during a depressive episode. Assessment and monitoring of food addiction symptoms may have utility in reducing the risk of increased BMI and adverse health outcomes in those experiencing more severe depressive symptoms.
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Affiliation(s)
- Jessica G Bartschi
- School of Psychology, Faculty of Arts, Social Sciences and Humanities, University of Wollongong, Wollongong, Australia.
| | - Lisa-Marie Greenwood
- School of Medicine and Psychology, The Australian National University, Canberra, Australia
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3
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Hall L, Dawel A, Greenwood LM, Monaghan C, Berryman K, Jack BN. Estimating statistical power for ERP studies using the auditory N1, Tb, and P2 components. Psychophysiology 2023; 60:e14363. [PMID: 37382363 DOI: 10.1111/psyp.14363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 11/04/2022] [Accepted: 01/11/2023] [Indexed: 06/30/2023]
Abstract
The N1, Tb, and P2 components of the event-related potential (ERP) are thought to reflect the sequential processing of auditory stimuli in the human brain. Despite their extensive use in biological, cognitive, and clinical neuroscience, there are no guidelines for how to appropriately power ERP studies using these components. In the present study, we investigated how the number of trials, number of participants, effect magnitude, and study design influenced statistical power. Using Monte Carlo simulations of ERP data from a passive listening task, we determined the probability of finding a statistically significant effect in 58,900 experiments repeated 1,000 times each. We found that as the number of trials, number of participants, and effect magnitude increased, so did statistical power. We also found that increasing the number of trials had a bigger effect on statistical power for within-subject designs than for between-subject designs, and that within-subject designs required a smaller number of trials and participants to provide the same level of statistical power for a given effect magnitude than between-subject designs. These results show that it is important to carefully consider these factors when designing ERP studies, rather than relying on tradition or anecdotal evidence. To improve the robustness and reproducibility of ERP research, we have built an online statistical power calculator (https://bradleynjack.shinyapps.io/ErpPowerCalculator), which we hope will allow researchers to estimate the statistical power of previous studies, as well as help them design appropriately-powered studies in the future.
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Affiliation(s)
- Lachlan Hall
- Research School of Psychology, Australian National University, Canberra, Australia
| | - Amy Dawel
- Research School of Psychology, Australian National University, Canberra, Australia
| | - Lisa-Marie Greenwood
- Research School of Psychology, Australian National University, Canberra, Australia
| | - Conal Monaghan
- Research School of Psychology, Australian National University, Canberra, Australia
| | - Kevin Berryman
- Research School of Psychology, Australian National University, Canberra, Australia
| | - Bradley N Jack
- Research School of Psychology, Australian National University, Canberra, Australia
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4
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Lorenzetti V, McTavish E, Broyd S, van Hell H, Thomson D, Ganella E, Kottaram AR, Beale C, Martin J, Galettis P, Solowij N, Greenwood LM. Daily Cannabidiol Administration for 10 Weeks Modulates Hippocampal and Amygdalar Resting-State Functional Connectivity in Cannabis Users: A Functional Magnetic Resonance Imaging Open-Label Clinical Trial. Cannabis Cannabinoid Res 2023. [PMID: 37603080 DOI: 10.1089/can.2022.0336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023] Open
Abstract
Introduction: Cannabis use is associated with brain functional changes in regions implicated in prominent neuroscientific theories of addiction. Emerging evidence suggests that cannabidiol (CBD) is neuroprotective and may reverse structural brain changes associated with prolonged heavy cannabis use. In this study, we examine how an ∼10-week exposure of CBD in cannabis users affected resting-state functional connectivity in brain regions functionally altered by cannabis use. Materials and Methods: Eighteen people who use cannabis took part in a ∼10 weeks open-label pragmatic trial of self-administered daily 200 mg CBD in capsules. They were not required to change their cannabis exposure patterns. Participants were assessed at baseline and post-CBD exposure with structural magnetic resonance imaging (MRI) and a functional MRI resting-state task (eyes closed). Seed-based connectivity analyses were run to examine changes in the functional connectivity of a priori regions-the hippocampus and the amygdala. We explored if connectivity changes were associated with cannabinoid exposure (i.e., cumulative cannabis dosage over trial, and plasma CBD concentrations and Δ9-tetrahydrocannabinol (THC) plasma metabolites postexposure), and mental health (i.e., severity of anxiety, depression, and positive psychotic symptom scores), accounting for cigarette exposure in the past month, alcohol standard drinks in the past month and cumulative CBD dose during the trial. Results: Functional connectivity significantly decreased pre-to-post the CBD trial between the anterior hippocampus and precentral gyrus, with a strong effect size (d=1.73). Functional connectivity increased between the amygdala and the lingual gyrus pre-to-post the CBD trial, with a strong effect size (d=1.19). There were no correlations with cannabinoids or mental health symptom scores. Discussion: Prolonged CBD exposure may restore/reduce functional connectivity differences reported in cannabis users. These new findings warrant replication in a larger sample, using robust methodologies-double-blind and placebo-controlled-and in the most vulnerable people who use cannabis, including those with more severe forms of Cannabis Use Disorder and experiencing worse mental health outcomes (e.g., psychosis, depression).
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Affiliation(s)
- Valentina Lorenzetti
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Center, School of Health and Behavioral Sciences, Australian Catholic University, Melbourne, Victoria, Australia
| | - Eugene McTavish
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Center, School of Health and Behavioral Sciences, Australian Catholic University, Melbourne, Victoria, Australia
| | - Samantha Broyd
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
- Illawarra Shoalhaven Local Health District, Wollongong, New South Wales, Australia
| | - Hendrika van Hell
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
| | - Diny Thomson
- Turner Institute for Brain and Mental Health, School of Psychological Science, Faculty of Medicine, Nursing and Health Sciences, Monash University, Australia
| | - Eleni Ganella
- Melbourne Neuropsychiatry Center, Department of Psychiatry, The University of Melbourne, Carlton South, Victoria, Australia
- Orygen, the National Center of Excellence in Youth Mental Health, Parkville, Victoria, Australia
| | - Akhil Raja Kottaram
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Center, School of Health and Behavioral Sciences, Australian Catholic University, Melbourne, Victoria, Australia
- Melbourne Neuropsychiatry Center, Department of Psychiatry, The University of Melbourne, Carlton South, Victoria, Australia
| | - Camilla Beale
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
| | - Jennifer Martin
- John Hunter Hospital, Newcastle, New South Wales, Australia
- Center for Drug Repurposing and Medicines Research, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales, Australia
- The Australian Center for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, New South Wales, Australia
| | - Peter Galettis
- Center for Drug Repurposing and Medicines Research, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales, Australia
- The Australian Center for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, New South Wales, Australia
| | - Nadia Solowij
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
- The Australian Center for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, New South Wales, Australia
| | - Lisa-Marie Greenwood
- The Australian Center for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, New South Wales, Australia
- Research School of Psychology, The Australian National University, Canberra, Australian Capital Territory, Australia
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5
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Cruwys T, Macleod E, Heffernan T, Walker I, Stanley SK, Kurz T, Greenwood LM, Evans O, Calear AL. Social group connections support mental health following wildfire. Soc Psychiatry Psychiatr Epidemiol 2023:10.1007/s00127-023-02519-8. [PMID: 37428193 DOI: 10.1007/s00127-023-02519-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 06/07/2023] [Indexed: 07/11/2023]
Abstract
PURPOSE As environmental disasters become more common and severe due to climate change, there is a growing need for strategies to bolster recovery that are proactive, cost-effective, and which mobilise community resources. AIMS We propose that building social group connections is a particularly promising strategy for supporting mental health in communities affected by environmental disasters. METHODS We tested the social identity model of identity change in a disaster context among 627 people substantially affected by the 2019-2020 Australian fires. RESULTS We found high levels of post-traumatic stress, strongly related to severity of disaster exposure, but also evidence of psychological resilience. Distress and resilience were weakly positively correlated. Having stronger social group connections pre-disaster was associated with less distress and more resilience 12-18 months after the disaster, via three pathways: greater social identification with the disaster-affected community, greater continuity of social group ties, and greater formation of new social group ties. New group ties were a mixed blessing, positively predicting both resilience and distress. CONCLUSIONS We conclude that investment in social resources is key to supporting mental health outcomes, not just reactively in the aftermath of disasters, but also proactively in communities most at risk.
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Affiliation(s)
- Tegan Cruwys
- School of Medicine and Psychology, The Australian National University, Canberra, Australia.
| | - Emily Macleod
- School of Medicine and Psychology, The Australian National University, Canberra, Australia
| | - Timothy Heffernan
- School of Medicine and Psychology, The Australian National University, Canberra, Australia
- UNSW School of Built Environment, Sydney, Australia
| | - Iain Walker
- School of Medicine and Psychology, The Australian National University, Canberra, Australia
- Melbourne Centre for Behaviour Change, University of Melbourne, Parkville, Australia
| | - Samantha K Stanley
- School of Medicine and Psychology, The Australian National University, Canberra, Australia
| | - Tim Kurz
- School of Psychological Science, University of Western Australia, Perth, Australia
| | - Lisa-Marie Greenwood
- School of Medicine and Psychology, The Australian National University, Canberra, Australia
| | - Olivia Evans
- School of Medicine and Psychology, The Australian National University, Canberra, Australia
| | - Alison L Calear
- Centre for Mental Health Research, The Australian National University, Canberra, Australia
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6
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Lorenzetti V, Kowalczyk M, Duehlmeyer L, Greenwood LM, Chye Y, Yücel M, Whittle S, Roberts CA. Brain Anatomical Alterations in Young Cannabis Users: Is it All Hype? A Meta-Analysis of Structural Neuroimaging Studies. Cannabis Cannabinoid Res 2023; 8:184-196. [PMID: 35443799 DOI: 10.1089/can.2021.0099] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Introduction: Cannabis use has a high prevalence in young youth and is associated with poor psychosocial outcomes. Such outcomes have been ascribed to the impact of cannabis exposure on the developing brain. However, findings from individual studies of volumetry in youth cannabis users are equivocal. Objectives: Our primary objective was to systematically review the evidence on brain volume differences between young cannabis users and nonusers aged 12-26 where profound neuromaturation occurs, accounting for the role of global brain volumes (GBVs). Our secondary objective was to systematically integrate the findings on the association between youth age and volumetry in youth cannabis users. Finally, we aimed to evaluate the quality of the evidence. Materials and Methods: A systematic search was run in three databases (PubMed, Scopus, and PsycINFO) and was reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We run meta-analyses (with and without controlling for GBV) of brain volume differences between young cannabis users and nonusers. We conducted metaregressions to explore the role of age on volumetric differences. Results: Sixteen studies were included. The reviewed samples included 830 people with mean age 22.5 years (range 14-26 years). Of these, 386 were cannabis users (with cannabis use onset at 15-19 years) and 444 were controls. We found no detectable group differences in any of the GBVs (intracranium, total brain, total white matter, and total gray matter) and regional brain volumes (i.e., hippocampus, amygdala, orbitofrontal cortex, and total cerebellum). Age and cannabis use level did not predict (standardized mean) volume group differences in metaregression. We found little evidence of publication bias (Egger's test p>0.1). Conclusions: Contrary to evidence in adult samples (or in samples mixing adults and youth), previous single studies in young cannabis users, and meta-analyses of brain function in young cannabis users, this early evidence suggests nonsignificant volume differences between young cannabis users and nonusers. While prolonged and long-term exposure to heavy cannabis use may be required to detect gross volume alterations, more studies in young cannabis users are needed to map in detail cannabis-related neuroanatomical changes.
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Affiliation(s)
- Valentina Lorenzetti
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioural and Health Sciences, Faculty of Health Sciences, Australian Catholic University, Fitzroy, Australia
| | - Magdalena Kowalczyk
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioural and Health Sciences, Faculty of Health Sciences, Australian Catholic University, Fitzroy, Australia
| | - Leonie Duehlmeyer
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioural and Health Sciences, Faculty of Health Sciences, Australian Catholic University, Fitzroy, Australia
| | - Lisa-Marie Greenwood
- Research School of Psychology, The Australian National University, Canberra, Australia
| | - Yann Chye
- BrainPark, The Turner Institute for Brain and Mental Health, School of Psychological Sciences and Monash Biomedical Imaging Facility, Clayton, Australia
| | - Murat Yücel
- BrainPark, The Turner Institute for Brain and Mental Health, School of Psychological Sciences and Monash Biomedical Imaging Facility, Clayton, Australia
| | - Sarah Whittle
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Carlton, Australia
| | - Carl A Roberts
- Department of Psychology, University of Liverpool, Liverpool, United Kingdom
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7
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Bartschi JG, Greenwood LM, Montgomery A, Dortants L, Weston-Green K, Huang XF, Pai N, Potter J, Schira MM, Croft R, Solowij N. Cannabidiol as a Treatment for Neurobiological, Behavioral, and Psychological Symptoms in Early-Stage Dementia: A Double-Blind, Placebo-Controlled Clinical Trial Protocol. Cannabis Cannabinoid Res 2022; 8:348-359. [PMID: 36040362 DOI: 10.1089/can.2021.0209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Rationale: The slowing of disease progression in dementia in the early stages of diagnosis is paramount to improving the quality of life for those diagnosed and their support networks. Accumulating evidence suggests that CBD, a constituent of Cannabis sativa, is associated with neuroprotective, neuroendocrine, and psychotherapeutic effects, suggesting that it may be beneficial to dementia treatment. However, no published human study to date has examined this possibility. This trial aims to determine whether daily treatment with CBD over a 12-week period is associated with improved neurobiological, behavioral, and psychological outcomes in individuals living with early-stage dementia. Methods: Sixty participants with early-stage dementia will be recruited for a randomized, double-blind, placebo-controlled clinical trial. Participants will be randomized into either 99.9% pure CBD or placebo treatment conditions and administered two capsules per day for 12 weeks. Participants will commence a 200 mg/day dose for 2 weeks before escalating to 300 mg/day for the remaining 10 weeks. Neuroimaging and blood-based neuroendocrine profiles will be assessed at baseline and post-treatment. Psychological and behavioral symptoms will be assessed at baseline, 6 weeks, and post-treatment. Monitoring of health and side-effects will be conducted through weekly home visits. Discussion: This study is among the first to investigate the effects of isolated CBD in improving neuroanatomical and neuroendocrine changes, alongside psychological symptoms, during the early stages of dementia diagnosis. The outcomes of this trial have the capacity to inform a potential novel and accessible treatment approach for individuals living with early-stage dementia, and in turn, improve quality of life, prognoses, and treatment outcomes. Trial Registration: This trial has been registered with the Therapeutic Goods Administration (CT-2020-CTN-03849-1v2) and the Australian and New Zealand Clinical Trials Registry (ACTRN12621001364864).
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Affiliation(s)
- Jessica G Bartschi
- School of Psychology, Faculty of the Arts, Social Sciences and Humanities, University of Wollongong, Wollongong, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia.,Australian Center for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, Australia
| | - Lisa-Marie Greenwood
- Australian Center for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, Australia.,Research School of Psychology, The Australian National University, Canberra, Australia
| | - Amy Montgomery
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia.,School of Nursing, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, Australia
| | - Lon Dortants
- School of Psychology, Faculty of the Arts, Social Sciences and Humanities, University of Wollongong, Wollongong, Australia.,Australian Center for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, Australia
| | - Katrina Weston-Green
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia.,Australian Center for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, Australia.,School of Medicine and Molecular Horizons, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, Australia
| | - Xu-Feng Huang
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia.,Australian Center for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, Australia.,School of Medicine and Molecular Horizons, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, Australia
| | - Nagesh Pai
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia.,School of Medicine and Molecular Horizons, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, Australia.,Southern Hospitals Network, Illawarra-Shoalhaven Local Health District, Warrawong, Australia
| | - Jan Potter
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia.,School of Medicine and Molecular Horizons, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, Australia.,Southern Hospitals Network, Illawarra-Shoalhaven Local Health District, Warrawong, Australia
| | - Mark M Schira
- School of Psychology, Faculty of the Arts, Social Sciences and Humanities, University of Wollongong, Wollongong, Australia
| | - Rodney Croft
- School of Psychology, Faculty of the Arts, Social Sciences and Humanities, University of Wollongong, Wollongong, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Nadia Solowij
- School of Psychology, Faculty of the Arts, Social Sciences and Humanities, University of Wollongong, Wollongong, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia.,Australian Center for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, Australia
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8
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Hallinan CM, Eden E, Graham M, Greenwood LM, Mills J, Popat A, Truong L, Bonomo Y. Over the counter low-dose cannabidiol: A viewpoint from the ACRE Capacity Building Group. J Psychopharmacol 2022; 36:661-665. [PMID: 34344208 DOI: 10.1177/02698811211035394] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Amidst growing global acceptance of medicinal cannabinoids as a potential therapeutic interest in cannabidiol (CBD) is increasing. In Australia in 2020, a government inquiry examined the barriers that the public are experiencing in accessing medicinal cannabis. A number of recommendations to improve access were made. In response to these recommendations, the Australian therapeutics regulatory authority down-scheduled CBD from Prescription Only (Schedule 4) to Pharmacist Only (Schedule 3). As a group of early to mid-career researchers of the Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), we propose some considerations in relation to over-the-counter availability of CBD and opportunities to improve knowledge about its potential therapeutic benefits alongside its increased uptake.
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Affiliation(s)
- Christine Mary Hallinan
- Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia.,Department of General Practice, Melbourne Medical School, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Edward Eden
- School of Medicine and Public Health, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW, Australia
| | - Myfanwy Graham
- School of Medicine and Public Health, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW, Australia.,Hunter Medical Research Institute, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW, Australia
| | | | - Jessica Mills
- School of Psychology, Illawarra Health and Medical Research Institute (IHMRI), Faculty of the Arts Social Sciences and Humanities, University of Wollongong, Wollongong, NSW, Australia
| | - Amirali Popat
- School of Pharmacy, Faculty of Health and Behavioural Sciences, The University of Queensland, Woolloongabba, QLD, Australia
| | - Linda Truong
- School of Medicine and Public Health, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW, Australia.,Department of Neurology, Sydney Children's Hospital Randwick, Sydney, NSW, Australia.,School of Women's and Children's Health, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Yvonne Bonomo
- Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia.,Department of Addiction Medicine, St Vincent's Hospital Melbourne, VIC, Australia
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9
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Thomson H, Labuschagne I, Greenwood LM, Robinson E, Sehl H, Suo C, Lorenzetti V. Is resting-state functional connectivity altered in regular cannabis users? A systematic review of the literature. Psychopharmacology (Berl) 2022; 239:1191-1209. [PMID: 34415377 DOI: 10.1007/s00213-021-05938-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 07/13/2021] [Indexed: 12/23/2022]
Abstract
RATIONALE Regular cannabis use has been associated with brain functional alterations within frontal, temporal, and striatal pathways assessed during various cognitive tasks. Whether such alterations are consistently reported in the absence of overt task performance needs to be elucidated to uncover the core neurobiological mechanisms of regular cannabis use. OBJECTIVES We aim to systematically review findings from studies that examine spontaneous fluctuations of brain function using functional Magnetic Resonance Imaging (fMRI) resting-state functional connectivity (rsFC) in cannabis users versus controls, and the association between rsFC and cannabis use chronicity, mental health symptoms, and cognitive performance. METHODS We conducted a PROSPERO registered systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and searched eight databases. RESULTS Twenty-one studies were included for review. Samples comprised 1396 participants aged 16 to 42 years, of which 737 were cannabis users and 659 were controls. Most studies found greater positive rsFC in cannabis users compared to controls between frontal-frontal, fronto-striatal, and fronto-temporal region pairings. The same region pairings were found to be preliminarily associated with varying measures of cannabis exposure. CONCLUSIONS The evidence to date shows that regular cannabis exposure is consistently associated with alteration of spontaneous changes in Blood Oxygenation Level-Dependent signal without any explicit cognitive input or output. These findings have implications for interpreting results from task-based fMRI studies of cannabis users, which may additionally tax overlapping networks. Future longitudinal rsFC fMRI studies are required to determine the clinical relevance of the findings and their link to the chronicity of use, mental health, and cognitive performance.
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Affiliation(s)
- Hannah Thomson
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioural and Health Sciences, Faculty of Health, Australian Catholic University, 17 Young Street, Fitzroy, VIC, 3065, Australia
| | - Izelle Labuschagne
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioural and Health Sciences, Faculty of Health, Australian Catholic University, 17 Young Street, Fitzroy, VIC, 3065, Australia
| | - Lisa-Marie Greenwood
- Research School of Psychology, Australian National University, Canberra, Australian Capital Territory, Australia.,The Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia
| | - Emily Robinson
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioural and Health Sciences, Faculty of Health, Australian Catholic University, 17 Young Street, Fitzroy, VIC, 3065, Australia
| | - Hannah Sehl
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioural and Health Sciences, Faculty of Health, Australian Catholic University, 17 Young Street, Fitzroy, VIC, 3065, Australia
| | - Chao Suo
- BrainPark, Turner Institute for Brain and Mental Health, School of Psychological Sciences and Monash Biomedical Imaging Facility, Monash University, Clayton, VIC, Australia
| | - Valentina Lorenzetti
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioural and Health Sciences, Faculty of Health, Australian Catholic University, 17 Young Street, Fitzroy, VIC, 3065, Australia.
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10
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Den Ouden L, Suo C, Albertella L, Greenwood LM, Lee RSC, Fontenelle LF, Parkes L, Tiego J, Chamberlain SR, Richardson K, Segrave R, Yücel M. Transdiagnostic phenotypes of compulsive behavior and associations with psychological, cognitive, and neurobiological affective processing. Transl Psychiatry 2022; 12:10. [PMID: 35013101 PMCID: PMC8748429 DOI: 10.1038/s41398-021-01773-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 12/02/2021] [Accepted: 12/16/2021] [Indexed: 01/10/2023] Open
Abstract
Compulsivity is a poorly understood transdiagnostic construct thought to underlie multiple disorders, including obsessive-compulsive disorder, addictions, and binge eating. Our current understanding of the causes of compulsive behavior remains primarily based on investigations into specific diagnostic categories or findings relying on one or two laboratory measures to explain complex phenotypic variance. This proof-of-concept study drew on a heterogeneous sample of community-based individuals (N = 45; 18-45 years; 25 female) exhibiting compulsive behavioral patterns in alcohol use, eating, cleaning, checking, or symmetry. Data-driven statistical modeling of multidimensional markers was utilized to identify homogeneous subtypes that were independent of traditional clinical phenomenology. Markers were based on well-defined measures of affective processing and included psychological assessment of compulsivity, behavioral avoidance, and stress, neurocognitive assessment of reward vs. punishment learning, and biological assessment of the cortisol awakening response. The neurobiological validity of the subtypes was assessed using functional magnetic resonance imaging. Statistical modeling identified three stable, distinct subtypes of compulsivity and affective processing, which we labeled "Compulsive Non-Avoidant", "Compulsive Reactive" and "Compulsive Stressed". They differed meaningfully on validation measures of mood, intolerance of uncertainty, and urgency. Most importantly, subtypes captured neurobiological variance on amygdala-based resting-state functional connectivity, suggesting they were valid representations of underlying neurobiology and highlighting the relevance of emotion-related brain networks in compulsive behavior. Although independent larger samples are needed to confirm the stability of subtypes, these data offer an integrated understanding of how different systems may interact in compulsive behavior and provide new considerations for guiding tailored intervention decisions.
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Affiliation(s)
- Lauren Den Ouden
- BrainPark, The Turner Institute for Brain and Mental Health, School of Psychological Sciences and Monash Biomedical Imaging Facility, Monash University, Clayton, Australia.
| | - Chao Suo
- BrainPark, The Turner Institute for Brain and Mental Health, School of Psychological Sciences and Monash Biomedical Imaging Facility, Monash University, Clayton, Australia
| | - Lucy Albertella
- BrainPark, The Turner Institute for Brain and Mental Health, School of Psychological Sciences and Monash Biomedical Imaging Facility, Monash University, Clayton, Australia
| | - Lisa-Marie Greenwood
- BrainPark, The Turner Institute for Brain and Mental Health, School of Psychological Sciences and Monash Biomedical Imaging Facility, Monash University, Clayton, Australia
- Research School of Psychology, ANU College of Health and Medicine, The Australian National University, Canberra, Australia
| | - Rico S C Lee
- BrainPark, The Turner Institute for Brain and Mental Health, School of Psychological Sciences and Monash Biomedical Imaging Facility, Monash University, Clayton, Australia
| | - Leonardo F Fontenelle
- BrainPark, The Turner Institute for Brain and Mental Health, School of Psychological Sciences and Monash Biomedical Imaging Facility, Monash University, Clayton, Australia
- D'Or Institute for Research and Education and Anxiety, Obsessive, Compulsive Research Program, Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Linden Parkes
- BrainPark, The Turner Institute for Brain and Mental Health, School of Psychological Sciences and Monash Biomedical Imaging Facility, Monash University, Clayton, Australia
- Department of Bioengineering, School of Engineering & Applied Science, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Jeggan Tiego
- Neural Systems and Behaviour Lab, The Turner Institute for Brain and Mental Health, School of Psychological Sciences and Monash Biomedical Imaging Facility, Monash University, Clayton, Australia
| | - Samuel R Chamberlain
- Department of Psychiatry, University of Southampton, Southampton, UK
- Southern Health NHS Foundation Trust, Southampton, UK
| | - Karyn Richardson
- BrainPark, The Turner Institute for Brain and Mental Health, School of Psychological Sciences and Monash Biomedical Imaging Facility, Monash University, Clayton, Australia
| | - Rebecca Segrave
- BrainPark, The Turner Institute for Brain and Mental Health, School of Psychological Sciences and Monash Biomedical Imaging Facility, Monash University, Clayton, Australia
| | - Murat Yücel
- BrainPark, The Turner Institute for Brain and Mental Health, School of Psychological Sciences and Monash Biomedical Imaging Facility, Monash University, Clayton, Australia
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11
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Sehl H, Terrett G, Greenwood LM, Kowalczyk M, Thomson H, Poudel G, Manning V, Lorenzetti V. Patterns of brain function associated with cannabis cue-reactivity in regular cannabis users: a systematic review of fMRI studies. Psychopharmacology (Berl) 2021; 238:2709-2728. [PMID: 34505940 PMCID: PMC8455486 DOI: 10.1007/s00213-021-05973-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 08/17/2021] [Indexed: 12/21/2022]
Abstract
RATIONALE Regular cannabis use (i.e. ≥ monthly) is highly prevalent, with past year use being reported by ~ 200 million people globally.High reactivity to cannabis cues is a key feature of regular cannabis use and has been ascribed to greater cannabis exposure and craving, but the underlying neurobiology is yet to be systematically integrated. OBJECTIVES We aim to systematically summarise the findings from fMRI studies which examined brain function in cannabis users while exposed to cannabis vs neutral stimuli during a cue-reactivity fMRI task. METHODS A systematic search of PsycINFO, PubMed and Scopus databases was pre-registered in PROSPERO (CRD42020171750) and conducted following PRISMA guidelines. Eighteen studies met inclusion/exclusion criteria. Samples comprised 918 participants (340 female) aged 16-38 years. Of these, 603 were regular cannabis users, and 315 were controls. RESULTS The literature consistently reported greater brain activity in cannabis users while exposed to cannabis vs neutral stimuli in three key brain areas: the striatum, the prefrontal (anterior cingulate, middle frontal) and the parietal cortex (posterior cingulate/precuneus) and additional brain regions (hippocampus, amygdala, thalamus, occipital cortex). Preliminary correlations emerged between cannabis craving and the function of partially overlapping regions (amygdala, striatum, orbitofrontal cortex ). CONCLUSIONS Exposure to cannabis-cues may elicit greater brain function and thus trigger cravings in regular cannabis users and thus trigger cannabis craving. Standardised and longitudinal assessments of cannabis use and related problems are required to profile with greater precision the neurobiology of cannabis cue-reactivity, and its role in predicting cravings and relapse.
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Affiliation(s)
- Hannah Sehl
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioural and Health Sciences, Faculty of Health Sciences, Australian Catholic University, Melbourne, Daniel Mannix building, 17 Young Street, Fitzroy, VIC 3065 Australia
| | - Gill Terrett
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioural and Health Sciences, Faculty of Health Sciences, Australian Catholic University, Melbourne, Daniel Mannix building, 17 Young Street, Fitzroy, VIC 3065 Australia
| | - Lisa-Marie Greenwood
- Research School of Psychology, Australian National University, Canberra, Australia ,The Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, New South Wales Australia
| | - Magdalena Kowalczyk
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioural and Health Sciences, Faculty of Health Sciences, Australian Catholic University, Melbourne, Daniel Mannix building, 17 Young Street, Fitzroy, VIC 3065 Australia
| | - Hannah Thomson
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioural and Health Sciences, Faculty of Health Sciences, Australian Catholic University, Melbourne, Daniel Mannix building, 17 Young Street, Fitzroy, VIC 3065 Australia
| | - Govinda Poudel
- Mary Mackillop Institute for Health Research, Australian Catholic University, Melbourne, Australia
| | - Victoria Manning
- Turning Point, Eastern Health, Monash University, Melbourne, Australia
| | - Valentina Lorenzetti
- Neuroscience of Addiction and Mental Health Program, Healthy Brain and Mind Research Centre, School of Behavioural and Health Sciences, Faculty of Health Sciences, Australian Catholic University, Melbourne, Daniel Mannix building, 17 Young Street, Fitzroy, VIC, 3065, Australia.
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12
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Den Ouden L, Tiego J, Lee RS, Albertella L, Greenwood LM, Fontenelle L, Yücel M, Segrave R. The role of Experiential Avoidance in transdiagnostic compulsive behavior: A structural model analysis. Addict Behav 2020; 108:106464. [PMID: 32428802 DOI: 10.1016/j.addbeh.2020.106464] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 05/05/2020] [Accepted: 05/06/2020] [Indexed: 12/15/2022]
Abstract
Compulsivity is recognized as a transdiagnostic phenotype, underlying a variety of addictive and obsessive-compulsive behaviors. However, current understanding of how it should be operationalized and the processes contributing to its development and maintenance is limited. The present study investigated if there was a relationship between the affective process Experiential Avoidance (EA), an unwillingness to tolerate negative internal experiences, and the frequency and severity of transdiagnostic compulsive behaviors. A large sample of adults (N = 469) completed online questionnaires measuring EA, psychological distress and the severity of seven obsessive-compulsive and addiction-related behaviors. Using structural equation modelling, results indicated a one-factor model of compulsivity was superior to the two-factor model (addictive- vs OCD-related behaviors). The effect of EA on compulsivity was fully mediated by psychological distress, which in turn had a strong direct effect on compulsivity. This suggests distress is a key mechanism in explaining why people with high EA are more prone to compulsive behaviors. The final model explained 41% of the variance in compulsivity, underscoring the importance of these constructs as likely risk and maintenance factors for compulsive behavior. Implications for designing effective psychological interventions for compulsivity are discussed.
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13
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Solowij N, Broyd S, Greenwood LM, van Hell H, Martelozzo D, Rueb K, Todd J, Liu Z, Galettis P, Martin J, Murray R, Jones A, Michie PT, Croft R. A randomised controlled trial of vaporised Δ 9-tetrahydrocannabinol and cannabidiol alone and in combination in frequent and infrequent cannabis users: acute intoxication effects. Eur Arch Psychiatry Clin Neurosci 2019; 269:17-35. [PMID: 30661105 DOI: 10.1007/s00406-019-00978-2] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 01/03/2019] [Indexed: 01/17/2023]
Abstract
Access to cannabis and cannabinoid products is increasing worldwide for recreational and medicinal use. Two primary compounds within cannabis plant matter, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), are both psychoactive, but only THC is considered intoxicating. There is significant interest in potential therapeutic properties of these cannabinoids and of CBD in particular. Some research has suggested that CBD may ameliorate adverse effects of THC, but this may be dose dependent as other evidence suggests possible potentiating effects of THC by low doses of CBD. We conducted a randomised placebo controlled trial to examine the acute effects of these compounds alone and in combination when administered by vaporisation to frequent and infrequent cannabis users. Participants (n = 36; 31 male) completed 5 drug conditions spaced one week apart, with the following planned contrasts: placebo vs CBD alone (400 mg); THC alone (8 mg) vs THC combined with low (4 mg) or high (400 mg) doses of CBD. Objective (blind observer ratings) and subjective (self-rated) measures of intoxication were the primary outcomes, with additional indices of intoxication examined. CBD showed some intoxicating properties relative to placebo. Low doses of CBD when combined with THC enhanced, while high doses of CBD reduced the intoxicating effects of THC. The enhancement of intoxication by low-dose CBD was particularly prominent in infrequent cannabis users and was consistent across objective and subjective measures. Most effects were significant at p < .0001. These findings are important to consider in terms of recommended proportions of THC and CBD in cannabis plant matter whether used medicinally or recreationally and have implications for novice or less experienced cannabis users.Trial registration: ISRCTN Registry Identifier: ISRCTN24109245.
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Affiliation(s)
- Nadia Solowij
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia. .,The Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia.
| | - Samantha Broyd
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Lisa-Marie Greenwood
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Hendrika van Hell
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Dave Martelozzo
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Kuna Rueb
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Juanita Todd
- School of Psychology, University of Newcastle, University Drive, Callaghan, NSW, Australia
| | - Zheng Liu
- School of Medicine and Public Health, Hunter Medical Research Institute, University of Newcastle, New Lambton Heights, NSW, Australia.,Clinical Pharmacology, Department of Medicine, The Royal Children's Hospital, Melbourne, VIC, Australia
| | - Peter Galettis
- The Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia.,School of Medicine and Public Health, Hunter Medical Research Institute, University of Newcastle, New Lambton Heights, NSW, Australia
| | - Jennifer Martin
- The Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, NSW, Australia.,School of Medicine and Public Health, Hunter Medical Research Institute, University of Newcastle, New Lambton Heights, NSW, Australia
| | - Robin Murray
- Institute of Psychiatry, Kings College London, London, UK
| | - Alison Jones
- Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, Australia
| | - Patricia T Michie
- School of Psychology, University of Newcastle, University Drive, Callaghan, NSW, Australia
| | - Rodney Croft
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
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14
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Solowij N, Broyd SJ, Beale C, Prick JA, Greenwood LM, van Hell H, Suo C, Galettis P, Pai N, Fu S, Croft RJ, Martin JH, Yücel M. Therapeutic Effects of Prolonged Cannabidiol Treatment on Psychological Symptoms and Cognitive Function in Regular Cannabis Users: A Pragmatic Open-Label Clinical Trial. Cannabis Cannabinoid Res 2018; 3:21-34. [PMID: 29607408 PMCID: PMC5870061 DOI: 10.1089/can.2017.0043] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Introduction: Chronic cannabis use has been associated with impaired cognition and elevated psychological symptoms, particularly psychotic-like experiences. While Δ9-tetrahydrocannabinol (THC) is thought to be primarily responsible for these deleterious effects, cannabidiol (CBD) is purported to have antipsychotic properties and to ameliorate cognitive, symptomatic, and brain harms in cannabis users. However, this has never been tested in a prolonged administration trial in otherwise healthy cannabis users. Here, we report the first study of prolonged CBD administration to a community sample of regular cannabis users in a pragmatic trial investigating potential restorative effects of CBD on psychological symptoms and cognition. Materials and Methods: Twenty frequent cannabis users (16 male, median age 25 years) underwent a 10-week open-label trial of 200 mg of daily oral CBD treatment, while continuing to use cannabis as usual. The majority of participants were daily cannabis users who had used cannabis for several years (median 5.5 years of regular use). Participants underwent psychological and cognitive assessments at baseline (BL) and post-treatment (PT) and were monitored weekly throughout the trial. Results: CBD was well tolerated with no reported side effects; however, participants retrospectively reported reduced euphoria when smoking cannabis. No impairments to cognition were found, nor were there deleterious effects on psychological function. Importantly, participants reported significantly fewer depressive and psychotic-like symptoms at PT relative to BL, and exhibited improvements in attentional switching, verbal learning, and memory. Increased plasma CBD concentrations were associated with improvements in attentional control and beneficial changes in psychological symptoms. Greater benefits were observed in dependent than in nondependent cannabis users. Conclusions: Prolonged CBD treatment appears to have promising therapeutic effects for improving psychological symptoms and cognition in regular cannabis users. Our findings require replication given the lack of a placebo control in this pragmatic trial, but suggest that CBD may be a useful adjunct treatment for cannabis dependence.
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Affiliation(s)
- Nadia Solowij
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia.,The Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, Australia
| | - Samantha J Broyd
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Camilla Beale
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Julie-Anne Prick
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Lisa-Marie Greenwood
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Hendrika van Hell
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Chao Suo
- Brain and Mental Health Laboratory, Monash Institute of Cognitive and Clinical Neurosciences, School of Psychological Sciences, Monash University, Clayton, Australia
| | - Peter Galettis
- The Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, Australia.,Discipline of Clinical Pharmacology, School of Medicine and Public Health, University of Newcastle, Callaghan, Australia
| | - Nagesh Pai
- Graduate School of Medicine and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Shanlin Fu
- Centre for Forensic Science, University of Technology Sydney, Ultimo, Australia
| | - Rodney J Croft
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
| | - Jennifer H Martin
- The Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), New Lambton Heights, Australia.,Discipline of Clinical Pharmacology, School of Medicine and Public Health, University of Newcastle, Callaghan, Australia
| | - Murat Yücel
- Brain and Mental Health Laboratory, Monash Institute of Cognitive and Clinical Neurosciences, School of Psychological Sciences, Monash University, Clayton, Australia
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15
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Greenwood LM, Leung S, Michie PT, Green A, Nathan PJ, Fitzgerald P, Johnston P, Solowij N, Kulkarni J, Croft RJ. The effects of glycine on auditory mismatch negativity in schizophrenia. Schizophr Res 2018; 191:61-69. [PMID: 28602646 DOI: 10.1016/j.schres.2017.05.031] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 05/22/2017] [Accepted: 05/25/2017] [Indexed: 11/24/2022]
Abstract
Glycine increases N-methyl-d-aspartate receptor (NMDAR) mediated glutamatergic function. Mismatch negativity (MMN) is a proposed biomarker of glutamate-induced improvements in clinical symptoms, however, the effect of glycine-mediated NMDAR activation on MMN in schizophrenia is not well understood. This study aimed to determine the effects of acute and 6-week chronic glycine administration on MMN in schizophrenia patients. MMN amplitude was compared at baseline between 22 patients (schizophrenia or schizoaffective disorder; receiving stable antipsychotic medication; multi-centre recruitment) and 21 age- and gender-matched controls. Patients underwent a randomised, double-blind, placebo-controlled clinical trial with glycine added to their regular antipsychotic medication (placebo, n=10; glycine, n=12). MMN was reassessed post-45-minutes of first dose (0.2g/kg) and post-6-weeks treatment (incremented to 0.6g/kg/day). Clinical symptoms were assessed at baseline and post-6-weeks treatment. At baseline, duration MMN was smaller in schizophrenia compared to controls. Acute glycine increased duration MMN (compared to placebo), whilst this difference was absent post-6-weeks treatment. Six weeks of chronic glycine administration improved PANSS-Total, PANSS-Negative and PANSS-General symptoms compared to placebo. Smaller baseline duration MMN was associated with greater PANSS-Negative symptoms and predicted (at trend level) PANSS-Negative symptom improvement post-6-weeks glycine treatment (not placebo). These findings support the benefits of chronic glycine administration and demonstrate, for the first time, that acute glycine improves duration MMN in schizophrenia. This result, together with smaller baseline duration MMN predicting greater clinical treatment response, suggests the potential for duration MMN as a biomarker of glycine-induced improvements in negative symptoms in schizophrenia.
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Affiliation(s)
- Lisa-Marie Greenwood
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia.
| | - Sumie Leung
- Centre for Human Psychopharmacology, Swinburne University of Technology, Victoria, Australia
| | - Patricia T Michie
- School of Psychology and Priority Research Centre for Translational Neuroscience and Mental Health, University of Newcastle, Newcastle, Australia; Schizophrenia Research Institute, Sydney, Australia
| | - Amity Green
- Monash Alfred Psychiatry Research Centre, Monash University, Melbourne, Australia
| | - Pradeep J Nathan
- Monash Alfred Psychiatry Research Centre, Monash University, Melbourne, Australia; Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom; School of Psychology and Psychiatry, Monash University, Melbourne, Australia
| | - Paul Fitzgerald
- Monash Alfred Psychiatry Research Centre, Monash University, Melbourne, Australia
| | - Patrick Johnston
- Department of Psychology and York Neuroimaging Centre, University of York, York, United Kingdom; School of Psychology and Counselling, Queensland University of Technology, Kelvin Grove, Australia
| | - Nadia Solowij
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia; Schizophrenia Research Institute, Sydney, Australia
| | - Jayashri Kulkarni
- Monash Alfred Psychiatry Research Centre, Monash University, Melbourne, Australia
| | - Rodney J Croft
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
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16
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Broyd SJ, Michie PT, Bruggemann J, van Hell HH, Greenwood LM, Croft RJ, Todd J, Lenroot R, Solowij N. Schizotypy and auditory mismatch negativity in a non-clinical sample of young adults. Psychiatry Res Neuroimaging 2016; 254:83-91. [PMID: 27388803 DOI: 10.1016/j.pscychresns.2016.06.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 05/20/2016] [Accepted: 06/18/2016] [Indexed: 11/24/2022]
Abstract
Schizophrenia may be conceptualised using a dimensional approach to examine trait-like expression such as schizotypy within non-clinical populations to better understand pathophysiology. A candidate psychosis-risk marker, the auditory mismatch negativity (MMN) is thought to index the functionality of glutamatergic NMDA receptor mediated neurotransmission. Although the MMN is robustly reduced in patients with schizophrenia, the association between MMN and schizotypy in the general population is under-investigated. Thirty-five healthy participants completed the Schizotypal Personality Questionnaire (SPQ) and a multi-feature MMN paradigm (standards 82%, 50ms, 1000Hz, 80dB) with duration (100ms), frequency (1200Hz) and intensity (90dB) deviants (6% each). Spearman's correlations were used to explore the association between schizotypal personality traits and MMN amplitude. Few associations were identified between schizotypal traits and MMN. Higher Suspiciousness subscale scores tended to be correlated with larger frequency MMN amplitude. A median-split comparison of the sample on Suspiciousness scores showed larger MMN (irrespective of deviant condition) in the High compared to the Low Suspiciousness group. The trend-level association between MMN and Suspiciousness is in contrast to the robustly attenuated MMN amplitude observed in schizophrenia. Reductions in MMN may reflect a schizophrenia-disease state, whereas non-clinical schizotypy may not be subserved by similar neuropathology.
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Affiliation(s)
- Samantha J Broyd
- School of Psychology, Centre for Health Initiatives and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia.
| | - Patricia T Michie
- School of Psychology and Priority Research Centre for Translational Neuroscience and Mental Health University of Newcastle, Newcastle, NSW, Australia
| | - Jason Bruggemann
- School of Psychiatry, University of New South Wales and Neuroscience Research Australia, Sydney, Australia
| | - Hendrika H van Hell
- School of Psychology, Centre for Health Initiatives and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Lisa-Marie Greenwood
- School of Psychology, Centre for Health Initiatives and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Rodney J Croft
- School of Psychology, Centre for Health Initiatives and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Juanita Todd
- School of Psychology and Priority Research Centre for Translational Neuroscience and Mental Health University of Newcastle, Newcastle, NSW, Australia
| | - Rhoshel Lenroot
- School of Psychiatry, University of New South Wales and Neuroscience Research Australia, Sydney, Australia
| | - Nadia Solowij
- School of Psychology, Centre for Health Initiatives and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
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Greenwood LM, Broyd SJ, Croft R, Todd J, Michie PT, Johnstone S, Murray R, Solowij N. Chronic effects of cannabis use on the auditory mismatch negativity. Biol Psychiatry 2014; 75:449-58. [PMID: 23830666 DOI: 10.1016/j.biopsych.2013.05.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 05/26/2013] [Accepted: 05/30/2013] [Indexed: 01/01/2023]
Abstract
BACKGROUND Cannabis use is associated with the development of psychotic symptoms and increased risk for schizophrenia. The mismatch negativity (MMN) is a brain event-related potential marker of change detection thought to index glutamatergic N-methyl-D-aspartate receptor-mediated neurotransmission, which is known to be deficient in schizophrenia. This study examined auditory MMN in otherwise healthy chronic cannabis users compared with nonuser control subjects. METHODS Forty-two chronic cannabis users and 44 nonuser healthy control subjects completed a multi-feature MMN paradigm, which included duration, frequency, and intensity deviants (deviants 6%; standards 82%). The MMN was compared between users and control subjects as well as between long- and short-term users and age- and gender-matched control subjects. Associations between MMN, cannabis use measures, and symptoms were examined. RESULTS The MMN amplitude was significantly reduced to frequency but not duration or intensity deviants in overall cannabis users relative to control subjects. Frequency MMN was similarly attenuated in short- and long-term users relative to control subjects. Long-term users also exhibited reduced duration MMN relative to control subjects and short-term users and this was correlated with increased duration of exposure to cannabis and increased psychotic-like experiences during intoxication. In short-term users, a younger age of onset of regular cannabis use and greater frequency of use were associated with greater psychotic-like experiences and symptomatic distress. CONCLUSIONS These results suggest impaired sensory memory that might reflect N-methyl-D-aspartate receptor dysfunction in chronic cannabis users. The pattern of MMN alterations in cannabis users differed from that typically observed in patients with schizophrenia, indicating overlapping but distinct underlying pathology.
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Affiliation(s)
- Lisa-Marie Greenwood
- School of Psychology and ψ-P3: Centre for Psychophysics, Psychophysiology and Psychopharmacology, University of Wollongong, Wollongong
| | - Samantha J Broyd
- School of Psychology and ψ-P3: Centre for Psychophysics, Psychophysiology and Psychopharmacology, University of Wollongong, Wollongong
| | - Rodney Croft
- School of Psychology and ψ-P3: Centre for Psychophysics, Psychophysiology and Psychopharmacology, University of Wollongong, Wollongong
| | - Juanita Todd
- School of Psychology and Priority Research Centre for Translational Neuroscience and Mental Health, University of Newcastle, Newcastle; Schizophrenia Research Institute, Sydney, New South Wales, Australia
| | - Patricia T Michie
- School of Psychology and Priority Research Centre for Translational Neuroscience and Mental Health, University of Newcastle, Newcastle; Schizophrenia Research Institute, Sydney, New South Wales, Australia
| | - Stuart Johnstone
- School of Psychology and ψ-P3: Centre for Psychophysics, Psychophysiology and Psychopharmacology, University of Wollongong, Wollongong
| | - Robin Murray
- Institute of Psychiatry, Kings College, London, United Kingdom
| | - Nadia Solowij
- School of Psychology and ψ-P3: Centre for Psychophysics, Psychophysiology and Psychopharmacology, University of Wollongong, Wollongong; Schizophrenia Research Institute, Sydney, New South Wales, Australia.
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