Jesus Pujol1, Laura Blanco-Hinojo2, Albert Batalla3, Marina López-Solà4, Ben J Harrison5, Carles Soriano-Mas6, Jose A Crippa7, Ana B Fagundo8, Joan Deus9, Rafael de la Torre10, Santiago Nogué11, Magí Farré12, Marta Torrens12, Rocío Martín-Santos13. 1. MRI Research Unit, CRC Mar, Hospital del Mar, Barcelona, Spain. Electronic address: jpujol@crccorp.es. 2. MRI Research Unit, CRC Mar, Hospital del Mar, Barcelona, Spain; Human Pharmacology and Neurosciences, Institute of Neuropsychiatry and Addiction, Hospital del Mar Research Institute, Barcelona, Spain. 3. Clinical Institute of Neuroscience, Hospital Clínic, IDIBAPS, CIBERSAM, University of Barcelona, Barcelona, Spain; Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Spain. 4. MRI Research Unit, CRC Mar, Hospital del Mar, Barcelona, Spain; Department of Psychology and Neuroscience, University of Colorado, Boulder, CO, USA. 5. Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Melbourne, Australia. 6. Department of Psychiatry, Bellvitge University Hospital-IDIBELL, Barcelona, Spain; Carlos III Health Institute, Ministry of Science and Innovation, CIBERSAM, Spain. 7. Department of Neuroscience and Behavior, RibeirãoPreto Medical School, University of São Paulo, Brazil; INCT Translational Medicine (CNPq), Brazil. 8. Human Pharmacology and Neurosciences, Institute of Neuropsychiatry and Addiction, Hospital del Mar Research Institute, Barcelona, Spain. 9. MRI Research Unit, CRC Mar, Hospital del Mar, Barcelona, Spain; Department of Clinical and Health Psychology, Autonomous University of Barcelona, Spain. 10. Human Pharmacology and Neurosciences, Institute of Neuropsychiatry and Addiction, Hospital del Mar Research Institute, Barcelona, Spain; Red-Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain. 11. Section of Clinical Toxicology, Emergency Service, Hospital Clínic, IDIBAPS, University of Barcelona, Barcelona, Spain. 12. Human Pharmacology and Neurosciences, Institute of Neuropsychiatry and Addiction, Hospital del Mar Research Institute, Barcelona, Spain; School of Medicine, Autonomous University of Barcelona, Red de Trastornos Adictivos (RETIC), Barcelona, Spain. 13. Clinical Institute of Neuroscience, Hospital Clínic, IDIBAPS, CIBERSAM, University of Barcelona, Barcelona, Spain; Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Spain; INCT Translational Medicine (CNPq), Brazil.
Abstract
BACKGROUND: Recreational drugs are generally used to intentionally alter conscious experience. Long-lasting cannabis users frequently seek this effect as a means to relieve negative affect states. As with conventional anxiolytic drugs, however, changes in subjective feelings may be associated with memory impairment. We have tested whether the use of cannabis, as a psychoactive compound, is associated with alterations in spontaneous activity in brain networks relevant to self-awareness, and whether such potential changes are related to perceived anxiety and memory performance. METHODS: Functional connectivity was assessed in the Default and Insula networks during resting state using fMRI in 28 heavy cannabis users and 29 control subjects. Imaging assessments were conducted during cannabis use in the unintoxicated state and repeated after one month of controlled abstinence. RESULTS: Cannabis users showed increased functional connectivity in the core of the Default and Insula networks and selective enhancement of functional anticorrelation between both. Reduced functional connectivity was observed in areas overlapping with other brain networks. Observed alterations were associated with behavioral measurements in a direction suggesting anxiety score reduction and interference with memory performance. Alterations were also related to the amount of cannabis used and partially persisted after one month of abstinence. CONCLUSIONS: Chronic cannabis use was associated with significant effects on the tuning and coupling of brain networks relevant to self-awareness, which in turn are integrated into brain systems supporting the storage of personal experience and motivated behavior. The results suggest potential mechanisms for recreational drugs to interfere with higher-order network interactions generating conscious experience.
BACKGROUND: Recreational drugs are generally used to intentionally alter conscious experience. Long-lasting cannabis users frequently seek this effect as a means to relieve negative affect states. As with conventional anxiolytic drugs, however, changes in subjective feelings may be associated with memory impairment. We have tested whether the use of cannabis, as a psychoactive compound, is associated with alterations in spontaneous activity in brain networks relevant to self-awareness, and whether such potential changes are related to perceived anxiety and memory performance. METHODS: Functional connectivity was assessed in the Default and Insula networks during resting state using fMRI in 28 heavy cannabis users and 29 control subjects. Imaging assessments were conducted during cannabis use in the unintoxicated state and repeated after one month of controlled abstinence. RESULTS: Cannabis users showed increased functional connectivity in the core of the Default and Insula networks and selective enhancement of functional anticorrelation between both. Reduced functional connectivity was observed in areas overlapping with other brain networks. Observed alterations were associated with behavioral measurements in a direction suggesting anxiety score reduction and interference with memory performance. Alterations were also related to the amount of cannabis used and partially persisted after one month of abstinence. CONCLUSIONS: Chronic cannabis use was associated with significant effects on the tuning and coupling of brain networks relevant to self-awareness, which in turn are integrated into brain systems supporting the storage of personal experience and motivated behavior. The results suggest potential mechanisms for recreational drugs to interfere with higher-order network interactions generating conscious experience.
Authors: Samuel J DeWitt; Ariel Ketcherside; Tim M McQueeny; Joseph P Dunlop; Francesca M Filbey Journal: Am J Drug Alcohol Abuse Date: 2015 Impact factor: 3.829
Authors: H Cheng; P D Skosnik; B J Pruce; M S Brumbaugh; J M Vollmer; D J Fridberg; B F O'Donnell; W P Hetrick; S D Newman Journal: J Psychopharmacol Date: 2014-09-18 Impact factor: 4.153