title: Mismatch Negativity and P50 Sensory Gating in Abstinent Former Cannabis Users.
abstract: Prolonged heavy exposure to cannabis is associated with impaired cognition and brain functional and structural alterations. We recently reported attenuated mismatch negativity (MMN) and altered P50 sensory gating in chronic cannabis users. This study investigated the extent of brain functional recovery (indexed by MMN and P50) in chronic users after cessation of use. Eighteen ex-users (median 13.5 years prior regular use; median 3.5 years abstinence) and 18 nonusers completed (1) a multifeature oddball task with duration, frequency, and intensity deviants and (2) a P50 paired-click paradigm. Trend level smaller duration MMN amplitude and larger P50 ratios (indicative of poorer sensory gating) were observed in ex-users compared to controls. Poorer P50 gating correlated with prior duration of cannabis use. Duration of abstinence was positively correlated with duration MMN amplitude, even after controlling for age and duration of cannabis use. Impaired sensory gating and attenuated MMN amplitude tended to persist in ex-users after prolonged cessation of use, suggesting a lack of full recovery. An association with prolonged duration of prior cannabis use may indicate persistent cannabis-related alterations to P50 sensory gating. Greater reductions in MMN amplitude with increasing abstinence (positive correlation) may be related to either self-medication or an accelerated aging process.
authors.affiliation: School of Psychology, University of Wollongong, Wollongong, NSW 2522, Australia; Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Samantha J
authors.initials: SJ
authors.lastname: Broyd
authors.affiliation: School of Psychology, University of Wollongong, Wollongong, NSW 2522, Australia; Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Lisa-marie
authors.initials: LM
authors.lastname: Greenwood
authors.affiliation: School of Psychology, University of Wollongong, Wollongong, NSW 2522, Australia; Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Hendrika H
authors.initials: HH
authors.lastname: van Hell
authors.affiliation: School of Psychology, University of Wollongong, Wollongong, NSW 2522, Australia; Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia; Centre for Health Initiatives, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Croft
authors.affiliation: School of Psychology, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Hannah
authors.initials: H
authors.lastname: Coyle
authors.affiliation: School of Psychology, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Ben
authors.initials: B
authors.lastname: Lee-Bates
authors.affiliation: School of Psychology and Priority Research Centre for Translational Neuroscience and Mental Health, University of Newcastle, Newcastle, NSW 2308, Australia; Schizophrenia Research Institute, Sydney, NSW 2021, Australia.
authors.forename: Juanita
authors.initials: J
authors.lastname: Todd
authors.affiliation: School of Psychology, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Johnstone
authors.affiliation: School of Psychology and Priority Research Centre for Translational Neuroscience and Mental Health, University of Newcastle, Newcastle, NSW 2308, Australia; Schizophrenia Research Institute, Sydney, NSW 2021, Australia.
authors.forename: Patricia T
authors.initials: PT
authors.lastname: Michie
authors.affiliation: School of Psychology, University of Wollongong, Wollongong, NSW 2522, Australia; Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia; Schizophrenia Research Institute, Sydney, NSW 2021, Australia.
authors.forename: Nadia
authors.initials: N
authors.lastname: Solowij
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D002540:Cerebral Cortex / Q000503:physiopathology*; D004569:Electroencephalography; D005071:Evoked Potentials; D005072:Evoked Potentials, Auditory; D005260:Female; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000009:adverse effects / Q000503:physiopathology*; D008875:Middle Aged; D055139:Sensory Gating; D055815:Young Adult