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Filbey FM, McQueeny T, Kadamangudi S, Bice C, Ketcherside A. Combined effects of marijuana and nicotine on memory performance and hippocampal volume. Behav Brain Res 2015; 293:46-53. [PMID: 26187691 DOI: 10.1016/j.bbr.2015.07.029] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 06/24/2015] [Accepted: 07/07/2015] [Indexed: 11/30/2022]
Abstract
Combined use of marijuana (MJ) and tobacco is highly prevalent in today's population. Individual use of either substance is linked to structural brain changes and altered cognitive function, especially with consistent reports of hippocampal volume deficits and poorer memory performance. However, the combined effects of MJ and tobacco on hippocampal structure and on learning and memory processes remain unknown. In this study, we examined both the individual and combined effects of MJ and tobacco on hippocampal volumes and memory performance in four groups of adults taken from two larger studies: MJ-only users (n=36), nicotine-only (Nic-only, n=19), combined marijuana and nicotine users (MJ+Nic, n=19) and non-using healthy controls (n=16). Total bilateral hippocampal volumes and memory performance (WMS-III logical memory) were compared across groups controlling for total brain size and recent alcohol use. Results found MJ and MJ+Nic groups had smaller total hippocampal volumes compared to Nic-only and controls. No significant difference between groups was found between immediate and delayed story recall. However, the controls showed a trend for larger hippocampal volumes being associated with better memory scores, while MJ+Nic users showed a unique inversion, whereby smaller hippocampal volume was associated with better memory. Overall, results suggest abnormalities in the brain-behavior relationships underlying memory processes with combined use of marijuana and nicotine use. Further research will need to address these complex interactions between MJ and nicotine.
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Affiliation(s)
- Francesca M Filbey
- The Center for BrainHealth, School of Behavioral and Brain Sciences, University of Texas at Dallas, United States.
| | - Tim McQueeny
- The Center for BrainHealth, School of Behavioral and Brain Sciences, University of Texas at Dallas, United States
| | - Shrinath Kadamangudi
- The Center for BrainHealth, School of Behavioral and Brain Sciences, University of Texas at Dallas, United States
| | - Collette Bice
- The Center for BrainHealth, School of Behavioral and Brain Sciences, University of Texas at Dallas, United States
| | - Ariel Ketcherside
- The Center for BrainHealth, School of Behavioral and Brain Sciences, University of Texas at Dallas, United States
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202
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Ito TA, Henry EA, Cordova KA, Bryan AD. Testing an expanded theory of planned behavior model to explain marijuana use among emerging adults in a promarijuana community. PSYCHOLOGY OF ADDICTIVE BEHAVIORS 2015; 29:576-89. [PMID: 26168227 DOI: 10.1037/adb0000098] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Opinions about marijuana use in the United States are becoming increasingly favorable, making it important to understand how psychosocial influences impact individuals' use in this context. Here, we used the theory of planned behavior to examine the influence of initial attitudes, norms, and efficacy to resist use on initial intentions and then to examine the effect of initial intentions on actual marijuana use measured 1 year later using data drawn from a community with relatively high use. We expanded the traditional theory of planned behavior model by investigating 2 types of normative influence (descriptive and injunctive) and 2 types of intentions (use intentions and proximity intentions), reasoning that exposure to high use in the population may produce high descriptive norms and proximity intentions overall, but not necessarily increase actual use. By contrast, we expected greater variability in injunctive norms and use intentions and that only use intentions would predict actual use. Consistent with hypotheses, intentions to use marijuana were predicted by injunctive norms (and attitudes) and in turn predicted marijuana use 1 year later. By contrast, descriptive norms were relatively high among all participants and did not predict intentions. Moreover, proximity intentions were not predictive of actual use. We also found that increasing intentions to use over a 1-year period predicted greater use. Given the greater efficacy of theory-based as compared with non-theory-based interventions, these findings provide critical information for the design of successful interventions to decrease marijuana-associated harms.
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203
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Hynes M, Demarco M, Araneda JC, Cumsille F. Prevalence of Marijuana Use among University Students in Bolivia, Colombia, Ecuador, and Peru. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:5233-40. [PMID: 25988312 PMCID: PMC4454964 DOI: 10.3390/ijerph120505233] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 05/01/2015] [Accepted: 05/07/2015] [Indexed: 12/03/2022]
Abstract
Young adults 18 to 25 years old show the highest prevalence of marijuana use in Latin America. This study analyzes the changes in prevalence of marijuana use among university students in the Andean Community (Bolivia, Colombia, Ecuador, and Peru) from two studies carried out in 2009 and in 2012. Data were collected through representative two-stage samples of universities and students in the Andean Community. An online survey was administered using a standardized questionnaire. Prevalence was calculated for lifetime, past year, and past month. Marijuana was the most widely used illicit substance consumed among university students, in 2009 and in 2012. Past month prevalence among university students in 2009 in Colombia was 5.27%, in Peru 1.00%, in Ecuador 1.68%, and in Bolivia 0.76%. Past month prevalence in 2012 in Colombia was 7.14%, in Ecuador 3.67%, in Peru 1.62%, and in Bolivia 1.45% in 2012. Among university students in the Andean Community, past month prevalence increased among both males and females between 2009 and 2012 in most countries. Marijuana continues to be the most commonly used illicit drug in Latin American countries. Increases in prevalence among young adults could have important implications for national drug policy.
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Affiliation(s)
- Marya Hynes
- Inter-American Observatory on Drugs, Inter-American Drug Abuse Control Commission (CICAD), Organization of American States (OAS), 1889 F Street NW, Washington, DC 20006, USA.
| | - Maria Demarco
- Inter-American Observatory on Drugs, Inter-American Drug Abuse Control Commission (CICAD), Organization of American States (OAS), 1889 F Street NW, Washington, DC 20006, USA.
| | - Juan Carlos Araneda
- Global SMART Programme (Latin America), United Nations Office on Drugs and Crime, 1889 F Street NW, Washington, DC 20006, USA.
| | - Francisco Cumsille
- Inter-American Observatory on Drugs, Inter-American Drug Abuse Control Commission (CICAD), Organization of American States (OAS), 1889 F Street NW, Washington, DC 20006, USA.
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204
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Jacobus J, Squeglia LM, Infante MA, Castro N, Brumback T, Meruelo AD, Tapert SF. Neuropsychological performance in adolescent marijuana users with co-occurring alcohol use: A three-year longitudinal study. Neuropsychology 2015; 29:829-843. [PMID: 25938918 DOI: 10.1037/neu0000203] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE The effect of adolescent marijuana use on brain development remains unclear despite relaxing legal restrictions, decreased perceived harm, and increasing use rates among youth. The aim of this 3-year prospective study was to evaluate the long-term neurocognitive effects of adolescent marijuana use. METHOD Adolescent marijuana users with concomitant alcohol use (MJ + ALC, n = 49) and control teens with limited substance use histories (CON, n = 59) were given neuropsychological and substance use assessments at project baseline, when they were ages 16-19. They were then reassessed 18 and 36 months later. Changes in neuropsychological measures were evaluated with repeated measures analysis of covariance (ANCOVA), controlling for lifetime alcohol use, and examined the effects of group, time, and group by time interactions on cognitive functioning. RESULTS MJ + ALC users performed significantly worse than controls, across time points, in the domains of complex attention, memory, processing speed, and visuospatial functioning (ps <.05). Earlier age of marijuana use onset was associated with poorer processing speed and executive functioning by the 3-year follow-up (ps ≤.02). CONCLUSIONS Frequent marijuana use throughout adolescence and into young adulthood appeared linked to worsened cognitive performance. Earlier age of onset appears to be associated with poorer neurocognitive outcomes that emerge by young adulthood, providing further support for the notion that the brain may be uniquely sensitive to frequent marijuana exposure during the adolescent phase of neurodevelopment. Continued follow-up of adolescent marijuana users will determine the extent of neural recovery that may occur if use abates.
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Affiliation(s)
| | | | | | - Norma Castro
- Department of Psychiatry, University of California San Diego
| | - Ty Brumback
- Department of Psychiatry, University of California San Diego
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205
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Goldsmith RS, Targino MC, Fanciullo GJ, Martin DW, Hartenbaum NP, White JM, Franklin P. Medical marijuana in the workplace: challenges and management options for occupational physicians. J Occup Environ Med 2015; 57:518-25. [PMID: 25951421 PMCID: PMC4410963 DOI: 10.1097/jom.0000000000000454] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Although possession and use of marijuana is prohibited by federal law, legalization in four states (Alaska, Colorado, Oregon, and Washington) and allowance for palliation and therapy in 19 others may reposition the drug away from the fringes of society. This evolving legal environment, and growing scientific evidence of its effectiveness for select health conditions, requires assessment of the safety and appropriateness of marijuana within the American workforce. Although studies have suggested that marijuana may be used with reasonable safety in some controlled environments, there are potential consequences to its use that necessitate employer scrutiny and concern. Several drug characteristics must be considered, including Δ-tetrahydrocannabinol (Δ-THC, or THC) concentration, route of administration, dose and frequency, and pharmacokinetics, as well as the risks inherent to particular workplace environments.
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Affiliation(s)
- Robert S. Goldsmith
- From Novartis Pharmaceuticals Corporation (Dr Goldsmith), East Hanover; Johnson & Johnson (Dr Targino), New Brunswick, NJ; Department of Anesthesiology, Dartmouth-Hitchcock Medical Center (Dr. Fanciullo), Lebanon, NH; UnityPoint Health - St. Luke's, Occupational Medicine (Dr Martin), Sioux City, IA; Occumedix, Inc. (Dr Hartenbaum), Dresher, PA; Kaye Scholer LLP (Mr White), Washington, DC; and Bayer Corporation (Dr Franklin), Asbury, NJ
| | - Marcelo C. Targino
- From Novartis Pharmaceuticals Corporation (Dr Goldsmith), East Hanover; Johnson & Johnson (Dr Targino), New Brunswick, NJ; Department of Anesthesiology, Dartmouth-Hitchcock Medical Center (Dr. Fanciullo), Lebanon, NH; UnityPoint Health - St. Luke's, Occupational Medicine (Dr Martin), Sioux City, IA; Occumedix, Inc. (Dr Hartenbaum), Dresher, PA; Kaye Scholer LLP (Mr White), Washington, DC; and Bayer Corporation (Dr Franklin), Asbury, NJ
| | - Gilbert J. Fanciullo
- From Novartis Pharmaceuticals Corporation (Dr Goldsmith), East Hanover; Johnson & Johnson (Dr Targino), New Brunswick, NJ; Department of Anesthesiology, Dartmouth-Hitchcock Medical Center (Dr. Fanciullo), Lebanon, NH; UnityPoint Health - St. Luke's, Occupational Medicine (Dr Martin), Sioux City, IA; Occumedix, Inc. (Dr Hartenbaum), Dresher, PA; Kaye Scholer LLP (Mr White), Washington, DC; and Bayer Corporation (Dr Franklin), Asbury, NJ
| | - Douglas W. Martin
- From Novartis Pharmaceuticals Corporation (Dr Goldsmith), East Hanover; Johnson & Johnson (Dr Targino), New Brunswick, NJ; Department of Anesthesiology, Dartmouth-Hitchcock Medical Center (Dr. Fanciullo), Lebanon, NH; UnityPoint Health - St. Luke's, Occupational Medicine (Dr Martin), Sioux City, IA; Occumedix, Inc. (Dr Hartenbaum), Dresher, PA; Kaye Scholer LLP (Mr White), Washington, DC; and Bayer Corporation (Dr Franklin), Asbury, NJ
| | - Natalie P. Hartenbaum
- From Novartis Pharmaceuticals Corporation (Dr Goldsmith), East Hanover; Johnson & Johnson (Dr Targino), New Brunswick, NJ; Department of Anesthesiology, Dartmouth-Hitchcock Medical Center (Dr. Fanciullo), Lebanon, NH; UnityPoint Health - St. Luke's, Occupational Medicine (Dr Martin), Sioux City, IA; Occumedix, Inc. (Dr Hartenbaum), Dresher, PA; Kaye Scholer LLP (Mr White), Washington, DC; and Bayer Corporation (Dr Franklin), Asbury, NJ
| | - Jeremy M. White
- From Novartis Pharmaceuticals Corporation (Dr Goldsmith), East Hanover; Johnson & Johnson (Dr Targino), New Brunswick, NJ; Department of Anesthesiology, Dartmouth-Hitchcock Medical Center (Dr. Fanciullo), Lebanon, NH; UnityPoint Health - St. Luke's, Occupational Medicine (Dr Martin), Sioux City, IA; Occumedix, Inc. (Dr Hartenbaum), Dresher, PA; Kaye Scholer LLP (Mr White), Washington, DC; and Bayer Corporation (Dr Franklin), Asbury, NJ
| | - Phillip Franklin
- From Novartis Pharmaceuticals Corporation (Dr Goldsmith), East Hanover; Johnson & Johnson (Dr Targino), New Brunswick, NJ; Department of Anesthesiology, Dartmouth-Hitchcock Medical Center (Dr. Fanciullo), Lebanon, NH; UnityPoint Health - St. Luke's, Occupational Medicine (Dr Martin), Sioux City, IA; Occumedix, Inc. (Dr Hartenbaum), Dresher, PA; Kaye Scholer LLP (Mr White), Washington, DC; and Bayer Corporation (Dr Franklin), Asbury, NJ
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206
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Romero K, Pavisian B, Staines WR, Feinstein A. Multiple sclerosis, cannabis, and cognition: A structural MRI study. NEUROIMAGE-CLINICAL 2015; 8:140-7. [PMID: 26106538 PMCID: PMC4473732 DOI: 10.1016/j.nicl.2015.04.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 04/06/2015] [Accepted: 04/07/2015] [Indexed: 02/09/2023]
Abstract
Objective A subset of patients with multiple sclerosis (MS) smoke cannabis to relieve symptoms including spasticity and pain. Recent evidence suggests that smoking cannabis further impairs cognition in people with MS and is linked to impaired functional brain changes. No such association, however, has been reported between cannabis use and structural brain changes, hence the focus of the present study. Methods Twenty patients with MS who smoke cannabis for symptom relief, and 19 matched non-cannabis-smoking MS patients were given the Brief Repeatable Neuropsychological Battery and structural MRI scans. Images were segmented into gray matter and white matter, and subsequently analysed with Partial Least Squares, a data-driven multivariate technique that explores brain–behaviour associations. Results In both groups, the Partial Least Squares analysis yielded significant correlations between cognitive scores and both gray matter (33% variance, p < .0001) and white matter (17% variance, p < .05) volume. Gray matter volume in the thalamus, basal ganglia, medial temporal, and medial prefrontal regions, and white matter volume in the fornix correlated with cognitive deficits. Crucially, the analysis indicated that brain volume reductions were associated with more extensive cognitive impairment in the cannabis versus the non-cannabis MS group. Interpretation These results suggest that cannabis use in MS results in more widespread cognitive deficits, which correlate with tissue volume in subcortical, medial temporal, and prefrontal regions. These are the first findings demonstrating an association between cannabis use, cognitive impairment and structural brain changes in MS patients. In MS, cannabis use moderates the association between cognition and brain integrity. Gray matter correlates with more widespread cognitive deficits in cannabis users. Hippocampal volume & white matter are correlated with memory only in cannabis users. Such differential patterns suggest that cannabis use has negative effects in MS patients.
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Affiliation(s)
- Kristoffer Romero
- Department of Psychiatry, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Bennis Pavisian
- Department of Psychiatry, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - William R Staines
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Anthony Feinstein
- Department of Psychiatry, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
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207
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Abstract
Recent research has suggested that marijuana use is associated with volumetric and shape differences in subcortical structures, including the nucleus accumbens and amygdala, in a dose-dependent fashion. Replication of such results in well controlled studies is essential to clarify the effects of marijuana. To that end, this retrospective study examined brain morphology in a sample of adult daily marijuana users (n = 29) versus nonusers (n = 29) and a sample of adolescent daily users (n = 50) versus nonusers (n = 50). Groups were matched on a critical confounding variable, alcohol use, to a far greater degree than in previously published studies. We acquired high-resolution MRI scans, and investigated group differences in gray matter using voxel-based morphometry, surface-based morphometry, and shape analysis in structures suggested to be associated with marijuana use, as follows: the nucleus accumbens, amygdala, hippocampus, and cerebellum. No statistically significant differences were found between daily users and nonusers on volume or shape in the regions of interest. Effect sizes suggest that the failure to find differences was not due to a lack of statistical power, but rather was due to the lack of even a modest effect. In sum, the results indicate that, when carefully controlling for alcohol use, gender, age, and other variables, there is no association between marijuana use and standard volumetric or shape measurements of subcortical structures.
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208
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Crane NA, Schuster RM, Mermelstein RJ, Gonzalez R. Neuropsychological sex differences associated with age of initiated use among young adult cannabis users. J Clin Exp Neuropsychol 2015; 37:389-401. [PMID: 25832823 DOI: 10.1080/13803395.2015.1020770] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Earlier initiation of cannabis use is associated with poorer neuropsychological functioning across several domains. Given well-documented sex differences in neuromaturation during adolescence, initiation of cannabis use during this time may affect neuropsychological functioning differently for males and females. METHOD In the current study, we examined sex differences in the relationship between age of initiated cannabis use and neuropsychological performance after controlling for amount of lifetime cannabis use in 44 male and 25 female young adult cannabis users. RESULTS We found that an earlier age of initiated use was related to poorer episodic memory, especially immediate recall, in females, but not in males. On the other hand, we found that, surprisingly, an earlier age of initiated use was associated with better decision making overall. However, exploratory analyses found sex-specific factors associated with decision making and age of initiated use, specifically that attention-deficit/hyperactivity disorder (ADHD) symptoms in females may drive the relationship between an earlier age of initiated use and better decision making. Further, an earlier age of initiated use was associated with less education, a lower IQ, and fewer years of mother's education for females, but more lifetime cannabis use for males. CONCLUSIONS Taken together, our findings suggest there are sex differences in the associations between age of initiated cannabis use and neuropsychological functioning. The current study provides preliminary evidence that males and females may have different neuropsychological vulnerabilities that place them at risk for initiating cannabis use and continued cannabis use, highlighting the importance of examining the impact of cannabis on neuropsychological functioning separately for males and females.
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Affiliation(s)
- Natania A Crane
- a Department of Psychology , University of Illinois at Chicago , Chicago , IL , USA
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209
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Nair MP, Figueroa G, Casteleiro G, Muñoz K, Agudelo M. Alcohol Versus Cannabinoids: A Review of Their Opposite Neuro-Immunomodulatory Effects and Future Therapeutic Potentials. JOURNAL OF ALCOHOLISM AND DRUG DEPENDENCE 2015; 3:184. [PMID: 26478902 PMCID: PMC4607066 DOI: 10.4172/2329-6488.1000184] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Due to the legalization of marijuana and the increased demand for cannabis and alcohol consumption, research efforts highlighting the biomedical consequences of the use of alcohol and cannabinoids are not only relevant to the substance abuse scientific field, but are also of public health interest. Moreover, an overview of the recent literature about alcohol and cannabinoids neuro-immunomodulatory effects highlighting their future therapeutic potentials will provide a significant contribution to science and medicine. Therefore, in the current review, we will first discuss briefly the prevalence of alcohol and marijuana abuse, followed by a discussion on the individual effects of alcohol and cannabinoids on the immune system; then, we will focus on the role of endocannabinoids on the alcohol-induced inflammatory effects. In addition, the review also incorporates cytokine array data obtained from human monocyte-derived dendritic cells, providing a different perspective on the alcohol and cannabinoid abuse divergent effects on cytokine production. The final section will highlight the therapeutic potential of cannabinoid receptors and the novel strategies to treat alcohol dependence as determined by in vitro, in vivo and clinical studies.
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Affiliation(s)
- Madhavan P. Nair
- Department of Immunology, Herbert Wertheim College of Medicine, AHC-I 417-B, Florida International University, Miami, FL 33199, USA
| | - Gloria Figueroa
- Department of Immunology, Herbert Wertheim College of Medicine, AHC-I 417-B, Florida International University, Miami, FL 33199, USA
| | - Gianna Casteleiro
- Department of Immunology, Herbert Wertheim College of Medicine, AHC-I 417-B, Florida International University, Miami, FL 33199, USA
| | - Karla Muñoz
- Department of Immunology, Herbert Wertheim College of Medicine, AHC-I 417-B, Florida International University, Miami, FL 33199, USA
| | - Marisela Agudelo
- Department of Immunology, Herbert Wertheim College of Medicine, AHC-I 417-B, Florida International University, Miami, FL 33199, USA
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210
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Killias M. Commentary: 'Smoking, caning and delinquency in a secondary modern school': a pioneer study by JW Palmer. Int J Epidemiol 2015; 44:23-5. [DOI: 10.1093/ije/dyu253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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211
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Cuzen NL, Koopowitz SM, Ferrett HL, Stein DJ, Yurgelun-Todd D. Methamphetamine and cannabis abuse in adolescence: a quasi-experimental study on specific and long-term neurocognitive effects. BMJ Open 2015; 5:e005833. [PMID: 25636791 PMCID: PMC4316423 DOI: 10.1136/bmjopen-2014-005833] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVES Methamphetamine abuse affects brain structure and function. Although methamphetamine and cannabis are commonly abused together, few studies have investigated the differential neurocognitive consequences of methamphetamine abuse with or without cannabis. Furthermore, the effects of drug use on the developing adolescent brain remain poorly understood. We compared neurocognitive function between adolescents with 'pure' methamphetamine abuse, those with comorbid methamphetamine and cannabis abuse, and healthy controls at baseline and follow-up. METHODS Individuals residing in the greater Cape Town region, between the ages of 13 and 18 years, were recruited into either Methamphetamine only group (Meth-only; n=10), Methamphetamine and cannabis group (Meth-cann; n=10) or healthy control (n=20) groups using a quasi-experimental design. All participants underwent a comprehensive neurocognitive assessment. Substance-use variables and psychiatric symptom counts were also recorded. A portion of the Meth-only and control participants completed 12-month follow-up assessments. RESULTS While the Meth-cann group demonstrated widespread neurocognitive deficits at baseline, these deficits were restricted to the self-monitoring domain in the Meth-only group at baseline and at follow-up. CONCLUSIONS Methamphetamine abuse with cannabis abuse is associated with significantly more neurocognitive impairment than methamphetamine abuse alone, and such deficits may be enduring.
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Affiliation(s)
- Natalie L Cuzen
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, Western Cape, South Africa
| | - Sheri-Michelle Koopowitz
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, Western Cape, South Africa
| | - Helen L Ferrett
- Department of Psychiatry, University of Stellenbosch, Cape Town, South Africa
| | - Dan J Stein
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, Western Cape, South Africa
| | - Deborah Yurgelun-Todd
- Brain Institute, University of Utah School of Medicine, Salt Lake City, Utah, USA
- Department of Psychiatry, University of Utah School of Medicine, Salt Lake City, Utah, USA
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212
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García-Morales V, Montero F, Moreno-López B. Cannabinoid agonists rearrange synaptic vesicles at excitatory synapses and depress motoneuron activity in vivo. Neuropharmacology 2015; 92:69-79. [PMID: 25595101 DOI: 10.1016/j.neuropharm.2014.12.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 12/14/2014] [Accepted: 12/30/2014] [Indexed: 01/30/2023]
Abstract
Impairment of motor skills is one of the most common acute adverse effects of cannabis. Related studies have focused mainly on psychomotor alterations, and little is known about the direct impact of cannabinoids (CBs) on motoneuron physiology. As key modulators of synaptic function, CBs regulate multiple neuronal functions and behaviors. Presynaptic CB1 mediates synaptic strength depression by inhibiting neurotransmitter release, via a poorly understood mechanism. The present study examined the effect of CB agonists on excitatory synaptic inputs incoming to hypoglossal motoneurons (HMNs) in vitro and in vivo. The endocannabinoid anandamide (AEA) and the synthetic CB agonist WIN 55,212-2 rapidly and reversibly induced short-term depression (STD) of glutamatergic synapses on motoneurons by a presynaptic mechanism. Presynaptic effects were fully reversed by the CB1-selective antagonist AM281. Electrophysiological and electron microscopy analysis showed that WIN 55,212-2 reduced the number of synaptic vesicles (SVs) docked to active zones in excitatory boutons. Given that AM281 fully abolished depolarization-induced depression of excitation, motoneurons can be feasible sources of CBs, which in turn act as retrograde messengers regulating synaptic function. Finally, microiontophoretic application of the CB agonist O-2545 reversibly depressed, presumably via CB1, glutamatergic inspiratory-related activity of HMNs in vivo. Therefore, evidence support that CBs, via presynaptic CB1, induce excitatory STD by reducing the readily releasable pool of SVs at excitatory synapses, then attenuating motoneuron activity. These outcomes contribute a possible mechanistic basis for cannabis-associated motor performance disturbances such as ataxia, dysarthria and dyscoordination.
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Affiliation(s)
- Victoria García-Morales
- Grupo de Neurodegeneración y Neuroreparación (GRUNEDERE), Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, Cádiz, Spain
| | - Fernando Montero
- Grupo de Neurodegeneración y Neuroreparación (GRUNEDERE), Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, Cádiz, Spain
| | - Bernardo Moreno-López
- Grupo de Neurodegeneración y Neuroreparación (GRUNEDERE), Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, Cádiz, Spain.
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213
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Hall W. What has research over the past two decades revealed about the adverse health effects of recreational cannabis use? Addiction 2015; 110:19-35. [PMID: 25287883 DOI: 10.1111/add.12703] [Citation(s) in RCA: 346] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 05/21/2014] [Accepted: 08/04/2014] [Indexed: 12/11/2022]
Abstract
AIMS To examine changes in the evidence on the adverse health effects of cannabis since 1993. METHODS A comparison of the evidence in 1993 with the evidence and interpretation of the same health outcomes in 2013. RESULTS Research in the past 20 years has shown that driving while cannabis-impaired approximately doubles car crash risk and that around one in 10 regular cannabis users develop dependence. Regular cannabis use in adolescence approximately doubles the risks of early school-leaving and of cognitive impairment and psychoses in adulthood. Regular cannabis use in adolescence is also associated strongly with the use of other illicit drugs. These associations persist after controlling for plausible confounding variables in longitudinal studies. This suggests that cannabis use is a contributory cause of these outcomes but some researchers still argue that these relationships are explained by shared causes or risk factors. Cannabis smoking probably increases cardiovascular disease risk in middle-aged adults but its effects on respiratory function and respiratory cancer remain unclear, because most cannabis smokers have smoked or still smoke tobacco. CONCLUSIONS The epidemiological literature in the past 20 years shows that cannabis use increases the risk of accidents and can produce dependence, and that there are consistent associations between regular cannabis use and poor psychosocial outcomes and mental health in adulthood.
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Affiliation(s)
- Wayne Hall
- The University of Queensland Centre for Youth Substance Abuse Research and The UQ Centre for Clinical Research, Herston, Australia; The National Addiction Centre, Kings College London, London, UK; National Drug and Alcohol Research Centre, University of New South Wales, New South Wales, Australia
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214
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Wetherill RR, Childress AR, Jagannathan K, Bender J, Young KA, Suh JJ, O’Brien CP, Franklin TR. Neural responses to subliminally presented cannabis and other emotionally evocative cues in cannabis-dependent individuals. Psychopharmacology (Berl) 2014; 231:1397-407. [PMID: 24186078 PMCID: PMC6218642 DOI: 10.1007/s00213-013-3342-z] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 10/10/2013] [Indexed: 01/22/2023]
Abstract
RATIONALE Addiction theories posit that drug-related cues maintain and contribute to drug use and relapse. Indeed, our recent study in cocaine-dependent patients demonstrated that subliminally presented cocaine-related stimuli activate reward neurocircuitry without being consciously perceived. Activation of reward neurocircuitry may provoke craving and perhaps prime an individual for subsequent drug-seeking behaviors. OBJECTIVES Using an equivalent paradigm, we tested whether cannabis cues activate reward neurocircuitry in treatment-seeking, cannabis-dependent individuals and whether activation was associated with relevant behavioral anchors: baseline cannabis craving (drug-seeking behavior) and duration of use (degree of conditioning). METHODS Twenty treatment-seeking, cannabis-dependent individuals (12 males) underwent event-related blood oxygen level-dependent functional magnetic resonance imaging during exposure to 33-ms cannabis, sexual, and aversive cues presented in a backward-masking paradigm. Drug use history and cannabis craving were assessed prior to imaging. RESULTS Participants showed increased activity to backward-masked cannabis cues in regions supporting reward detection and interoception, including the left anterior insula, left ventral striatum/amygdala, and right ventral striatum. Cannabis cue-related activity in the bilateral insula and perigenual anterior cingulate cortex was positively associated with baseline cannabis craving, and cannabis cue-related activity in the medial orbitofrontal cortex was positively correlated with years of cannabis use. Neural responses to backward-masked sexual cues were similar to those observed during cannabis cue exposure, while activation to aversive cues was observed only in the left anterior insula and perigenual anterior cingulate cortex. CONCLUSIONS These data highlight the sensitivity of the brain to subliminal reward signals and support hypotheses promoting a common pathway of appetitive motivation.
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Affiliation(s)
- Reagan R. Wetherill
- Department of Psychiatry, University of Pennsylvania, 3900 Chestnut Street, Philadelphia, PA 19104, USA
| | - Anna Rose Childress
- Department of Psychiatry, University of Pennsylvania, 3900 Chestnut Street, Philadelphia, PA 19104, USA; Philadelphia VA Medical Center, Philadelphia, PA 19104, USA
| | - Kanchana Jagannathan
- Department of Psychiatry, University of Pennsylvania, 3900 Chestnut Street, Philadelphia, PA 19104, USA
| | - Julian Bender
- Department of Psychiatry, University of Pennsylvania, 3900 Chestnut Street, Philadelphia, PA 19104, USA
| | - Kimberly A. Young
- Department of Psychiatry, University of Pennsylvania, 3900 Chestnut Street, Philadelphia, PA 19104, USA
| | - Jesse J. Suh
- Department of Psychiatry, University of Pennsylvania, 3900 Chestnut Street, Philadelphia, PA 19104, USA; Philadelphia VA Medical Center, Philadelphia, PA 19104, USA
| | - Charles P. O’Brien
- Department of Psychiatry, University of Pennsylvania, 3900 Chestnut Street, Philadelphia, PA 19104, USA; Philadelphia VA Medical Center, Philadelphia, PA 19104, USA
| | - Teresa R. Franklin
- Department of Psychiatry, University of Pennsylvania, 3900 Chestnut Street, Philadelphia, PA 19104, USA
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215
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Preliminary evidence for a sex-specific relationship between amount of cannabis use and neurocognitive performance in young adult cannabis users. J Int Neuropsychol Soc 2013; 19:1009-15. [PMID: 23962414 PMCID: PMC3895398 DOI: 10.1017/s135561771300088x] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Accumulating evidence suggests neuropsychological deficits from cannabis use, with a burgeoning area of preclinical research indicating possible sex-differences. However, few studies have examined how cannabis use may differentially impact neurocognition in male and female cannabis users. As such, we examined potential sex-differences in associations between amount of cannabis use (across several time frames) and neurocognitive performance among young adult regular cannabis users. Consistent with previous studies, more cannabis use was generally associated with poorer episodic memory and decision-making, but not other measures of inhibitory control. However, patterns of results suggested sex-specific dissociations. In particular, more cannabis use was more consistently associated with poorer episodic memory performance in females than males. Conversely, more cannabis use was associated with poorer decision-making performance for males, but not females. These results provide further evidence for residual cannabis-associated neurocognitive deficits and suggest the importance of examining the impact of cannabis on neurocognition separately for males and females.
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216
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The neural correlates of mental rotation abilities in cannabis-abusing patients with schizophrenia: an FMRI study. SCHIZOPHRENIA RESEARCH AND TREATMENT 2013; 2013:543842. [PMID: 23970971 PMCID: PMC3730190 DOI: 10.1155/2013/543842] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 06/20/2013] [Accepted: 07/02/2013] [Indexed: 11/17/2022]
Abstract
Growing evidence suggests that cannabis abuse/dependence is paradoxically associated with better cognition in schizophrenia. Accordingly, we performed a functional magnetic resonance imaging (fMRI) study of visuospatial abilities in 14 schizophrenia patients with cannabis abuse (DD), 14 nonabusing schizophrenia patients (SCZ), and 21 healthy controls (HCs). Participants performed a mental rotation task while being scanned. There were no significant differences in the number of mistakes between schizophrenia groups, and both made more mistakes on the mental rotation task than HC. Relative to HC, SCZ had increased activations in the left thalamus, while DD patients had increased activations in the right supramarginal gyrus. In both cases, hyper-activations are likely to reflect compensatory efforts. In addition, SCZ patients had decreased activations in the left superior parietal gyrus compared to both HC and DD patients. This latter result tentatively suggests that the neurophysiologic processes underlying visuospatial abilities are partially preserved in DD, relative to SCZ patients, consistently with the findings showing that cannabis abuse in schizophrenia is associated with better cognitive functioning. Further fMRI studies are required to examine the neural correlates of other cognitive dysfunctions in schizophrenia patients with and without comorbid cannabis use disorder.
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217
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Gonzalez R, Schuster RM, Mermelstein RJ, Vassileva J, Martin EM, Diviak KR. Performance of young adult cannabis users on neurocognitive measures of impulsive behavior and their relationship to symptoms of cannabis use disorders. J Clin Exp Neuropsychol 2012; 34:962-76. [PMID: 22882144 PMCID: PMC3488122 DOI: 10.1080/13803395.2012.703642] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Recent studies suggest that abstinent cannabis users show deficits on neurocognitive laboratory tasks of impulsive behavior. But results are mixed, and less is known on the performance of non-treatment-seeking, young adult cannabis users. Importantly, relationships between performance on measures of impulsive behavior and symptoms of cannabis addiction remain relatively unexplored. We compared young adult current cannabis users (CU, n = 65) and nonusing controls (NU, n = 65) on several laboratory measures of impulsive behavior, as well as on a measure of episodic memory commonly impacted by cannabis use. The CU group performed more poorly than the NU group on the Hopkins Verbal Learning Test-Revised Total Immediate Recall and Delayed Recall. No significant differences were observed on the measures of impulsive behavior (i.e., Iowa Gambling Task, IGT; Go-Stop Task; Monetary Choice Questionnaire; Balloon Analogue Risk Task). We examined relationships between neurocognitive performance and symptoms of cannabis use disorder symptoms (Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition, DSM-IV CUD) among the CU group, which revealed that poorer IGT performance was associated with more symptoms of DSM-IV CUD. Our results show poorer memory performance among young adult cannabis users than among healthy controls, but no differences on measures of impulsive behavior. However, performance on a specific type of impulsive behavior (i.e., poorer decision making) was associated with more cannabis use disorder symptoms. These results provide preliminary evidence to suggest that decision-making deficits may be more strongly associated with problems experienced from cannabis use, rather than solely being a consequence of cannabis use, per se.
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Affiliation(s)
- Raul Gonzalez
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, USA.
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