title: Intact inhibitory control processes in abstinent drug abusers (I): a functional neuroimaging study in former cocaine addicts.
abstract: Neuroimaging studies in current cocaine dependent (CD) individuals consistently reveal cortical hypoactivity across regions of the response inhibition circuit (RIC). Dysregulation of this critical executive network is hypothesized to account for the lack of inhibitory control that is a hallmark of the addictive phenotype, and chronic abuse is believed to compound the issue. A crucial question is whether deficits in this circuit persist after drug cessation, and whether recovery of this system will be seen after extended periods of abstinence, a question with implications for treatment course and outcome. Utilizing functional magnetic resonance imaging (fMRI), we examined activation in nodes of the RIC in abstinent CD individuals (n = 27) and non-using controls (n = 45) while they performed a motor response inhibition task. In contrast to current users, these abstinent individuals, despite extended histories of chronic cocaine-abuse (average duration of use = 8.2 years), performed the task just as efficiently as non-users. In line with these behavioral findings, no evidence for between-group differences in activation of the RIC was found and instead, robust activations were apparent in both groups within the well-characterized nodes of the RIC. Similarly, our complementary Electroencephalography (EEG) investigation also showed an absence of behavioral and electrophysiological deficits in abstinent drug abusers. These results are consistent with an amelioration of neurobiological deficits in inhibitory circuitry following drug cessation, and could help explain how long-term abstinence is maintained. Finally, regression analyses revealed a significant association between level of activation in the right insula with inhibition success and increased abstinence duration in the CD cohort suggesting that this region may be integral to successful recovery from cocaine addiction.
authors.affiliation: The Cognitive Neurophysiology Laboratory, The Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, NY 10962, USA; The Sheryl and Daniel R. Tishman Cognitive Neurophysiology Laboratory, Children's Evaluation and Rehabilitation Center (CERC), Department of Pediatrics, Albert Einstein College of Medicine, Van Etten Building - Wing 1C, 1300 Morris Park Avenue, Bronx, NY 10461, USA; The Sheryl and Daniel R. Tishman Cognitive Neurophysiology Laboratory, Children's Evaluation and Rehabilitation Center (CERC), Department of Neuroscience, Albert Einstein College of Medicine, Van Etten Building - Wing 1C, 1300 Morris Park Avenue, Bronx, NY 10461, USA; Program in Cognitive Neuroscience, Department of Psychology, The City College of the City University of New York, 138th Street & Convent Ave, New York, NY 10031, USA; Department of Biology, The City College of the City University of New York, 138th Street & Convent Ave, New York, NY 10031, USA. Electronic address: rbell@einstein.yu.edu.
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Bell
authors.affiliation: The Cognitive Neurophysiology Laboratory, The Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, NY 10962, USA; The Sheryl and Daniel R. Tishman Cognitive Neurophysiology Laboratory, Children's Evaluation and Rehabilitation Center (CERC), Department of Pediatrics, Albert Einstein College of Medicine, Van Etten Building - Wing 1C, 1300 Morris Park Avenue, Bronx, NY 10461, USA; The Sheryl and Daniel R. Tishman Cognitive Neurophysiology Laboratory, Children's Evaluation and Rehabilitation Center (CERC), Department of Neuroscience, Albert Einstein College of Medicine, Van Etten Building - Wing 1C, 1300 Morris Park Avenue, Bronx, NY 10461, USA; Program in Cognitive Neuroscience, Department of Psychology, The City College of the City University of New York, 138th Street & Convent Ave, New York, NY 10031, USA; Department of Biology, The City College of the City University of New York, 138th Street & Convent Ave, New York, NY 10031, USA. Electronic address: john.foxe@einstein.yu.edu.
authors.forename: John J
authors.initials: JJ
authors.lastname: Foxe
authors.affiliation: The Sheryl and Daniel R. Tishman Cognitive Neurophysiology Laboratory, Children's Evaluation and Rehabilitation Center (CERC), Department of Pediatrics, Albert Einstein College of Medicine, Van Etten Building - Wing 1C, 1300 Morris Park Avenue, Bronx, NY 10461, USA; The Sheryl and Daniel R. Tishman Cognitive Neurophysiology Laboratory, Children's Evaluation and Rehabilitation Center (CERC), Department of Neuroscience, Albert Einstein College of Medicine, Van Etten Building - Wing 1C, 1300 Morris Park Avenue, Bronx, NY 10461, USA; The Gordon F. Derner Institute of Advanced Psychological Studies, Adelphi University, Garden City, NY 11530-0701, USA. Electronic address: lars.ross@einstein.yu.edu.
authors.forename: Lars A
authors.initials: LA
authors.lastname: Ross
authors.affiliation: The Cognitive Neurophysiology Laboratory, The Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, NY 10962, USA; University of Vermont, Department of Psychiatry, 1 South Prospect St., Burlington, VT 05401, USA. Electronic address: hugh.garavan@uvm.edu.
authors.forename: Hugh
authors.initials: H
authors.lastname: Garavan
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology; D019970:Cocaine-Related Disorders / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007266:Inhibition, Psychological; D008279:Magnetic Resonance Imaging; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009434:Neural Pathways / Q000503:physiopathology; D009483:Neuropsychological Tests; D012044:Regression Analysis; D013647:Task Performance and Analysis
keywords: Abstinence; Cocaine; Insula; Recovery; Response inhibition; fMRI