title: Relationship between working-memory network function and substance use: a 3-year longitudinal fMRI study in heavy cannabis users and controls.
abstract: Deficient executive functions play an important role in the development of addiction. Working-memory may therefore be a powerful predictor of the course of drug use, but chronic substance use may also impair working-memory. The aim of this 3-year longitudinal neuro-imaging study was to investigate the relationship between substance use (e.g. alcohol, cannabis, nicotine, illegal psychotropic drugs) and working-memory network function over time in heavy cannabis users and controls. Forty-nine participants performed an n-back working-memory task at baseline and at 3-year follow-up. At follow-up, there were 22 current heavy cannabis users, 4 abstinent heavy cannabis users and 23 non-cannabis-using controls. Tensor-independent component analysis (Tensor-ICA) was used to investigate individual differences in working-memory network functionality over time. Within the group of cannabis users, cannabis-related problems remained stable, whereas alcohol-related problems, nicotine dependence and illegal psychotropic substance use increased over time. At both measurements, behavioral performance and network functionality during the n-back task did not differ between heavy cannabis users and controls. Although n-back accuracy improved, working-memory network function remained stable over time. Within the group of cannabis users, working-memory network functionality was not associated with substance use. These results suggest that sustained moderate to heavy levels of cannabis, nicotine, alcohol and illegal psychotropic substance use do not change working-memory network functionality. Moreover, baseline network functionality did not predict cannabis use and related problems three years later, warranting longitudinal studies in more chronic or dependent cannabis users.
authors.affiliation: Addiction Development and Psychopathology (ADAPT) Lab, Department of Psychology, University of Amsterdam, The Netherlands; Department of Psychiatry, Academic Medical Centre, University of Amsterdam, The Netherlands; Department of Psychology, Leiden University, The Netherlands.
authors.forename: Janna
authors.initials: J
authors.lastname: Cousijn
authors.forename: Wilhelmina A M
authors.initials: WA
authors.lastname: Vingerhoets
authors.forename: Laura
authors.initials: L
authors.lastname: Koenders
authors.forename: Lieuwe
authors.initials: L
authors.lastname: de Haan
authors.forename: Wim
authors.initials: W
authors.lastname: van den Brink
authors.forename: Reinout W
authors.initials: RW
authors.lastname: Wiers
authors.forename: Anna E
authors.initials: AE
authors.lastname: Goudriaan
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000704:Analysis of Variance; D016739:Behavior, Addictive / Q000453:epidemiology / Q000503:physiopathology; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods*; D016022:Case-Control Studies; D018450:Disease Progression; D013759:Dronabinol / Q000009:adverse effects; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D016014:Linear Models; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology / Q000503:physiopathology*; D008569:Memory Disorders / Q000453:epidemiology / Q000503:physiopathology*; D008570:Memory, Short-Term / Q000187:drug effects / Q000502:physiology*; D009415:Nerve Net / Q000503:physiopathology; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011619:Psychotropic Drugs / Q000009:adverse effects; D012307:Risk Factors; D012720:Severity of Illness Index; D019966:Substance-Related Disorders / Q000453:epidemiology / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D011619:Psychotropic Drugs; D013759:Dronabinol
keywords: Cannabis; cannabis use disorder; fMRI; n-back; working-memory