Philadelphia, PA, September 23, 2013 – It is often said that once people develop an addiction, they can never completely eliminate their attraction to the abused substance. New findings provide further support for this notion by suggesting that even long-term abstinence from cocaine does not result in a complete normalization of brain circuitry.
Scientists are currently trying to answer some of the 'chicken and egg' questions surrounding the abuse of drugs. In particular, one of those questions is whether individuals who abuse psychostimulants like cocaine are more impulsive and show alterations in brain reward circuits as a consequence of using the drug, or whether such abnormalities existed prior to their drug use. In the former case, one might expect brain alterations to normalize following prolonged drug abstinence.
To address these questions, Krishna Patel at Institute of Living/Hartford Hospital and colleagues compared neural responses between three groups of people who were asked to complete a task that resembles bidding on eBay items. The 3 groups consisted of 47 healthy controls, 42 currently drug-abusing cocaine users, and 35 former cocaine users who had been abstinent an average of 4 years. They also compared all three groups on their levels of impulsivity and reward responding.
They found that active users showed abnormal activation in multiple brain regions involved with reward processing, and that the abstinent individuals who were previously cocaine dependent manifested differences in a subset of those regions. Both current and former cocaine users displayed similarly elevated impulsivity measures compared to healthy controls, which may indicate that these individuals had a pre-existing risk for addiction. Indeed, the degree of impulsivity correlated with several of the brain activation abnormalities.
These findings suggest that prolonged abstinence from cocaine may normalize only a subset of the brain abnormalities associated with active drug use.
"The knowledge that some neural changes associated with addiction persist despite long periods of abstinence is important because it supports clinical wisdom that recovery from addiction is a lifelong process," says Dr. John Krystal, Editor of Biological Psychiatry. "Further, it is the start of a deeper question: How do these persisting changes develop and how can they be reversed?"
The authors agree that further studies will be needed to investigate such questions, including the continued attempt to determine the extent to which differences in former cocaine users reflect aspects of pre-existing features, exposure to cocaine, or recovery.
The article is "Robust Changes in Reward Circuitry During Reward Loss in Current and Former Cocaine Users During Performance of a Monetary Incentive Delay Task" by Krishna T. Patel, Michael C. Stevens, Shashwath A. Meda, Christine Muska, Andre D. Thomas, Marc N. Potenza, and Godfrey D. Pearlson (doi: 10.1016/j.biopsych.2013.04.029). The article appears in Biological Psychiatry, Volume 74, Issue 7 (October 1, 2013), published by Elsevier.
Notes for editors
Full text of the article is available to credentialed journalists upon request; contact Rhiannon Bugno at +1 214 648 0880 or Biol.Psych@utsouthwestern.edu. Journalists wishing to interview the authors may contact Krishna Patel at +1 860 545 7032 or firstname.lastname@example.org.
The authors' affiliations, and disclosures of financial and conflicts of interests are available in the article.
John H. Krystal, M.D., is Chairman of the Department of Psychiatry at the Yale University School of Medicine and a research psychiatrist at the VA Connecticut Healthcare System. His disclosures of financial and conflicts of interests are available here.
About Biological Psychiatry
Biological Psychiatry is the official journal of the Society of Biological Psychiatry, whose purpose is to promote excellence in scientific research and education in fields that investigate the nature, causes, mechanisms and treatments of disorders of thought, emotion, or behavior. In accord with this mission, this peer-reviewed, rapid-publication, international journal publishes both basic and clinical contributions from all disciplines and research areas relevant to the pathophysiology and treatment of major psychiatric disorders.
The journal publishes novel results of original research which represent an important new lead or significant impact on the field, particularly those addressing genetic and environmental risk factors, neural circuitry and neurochemistry, and important new therapeutic approaches. Reviews and commentaries that focus on topics of current research and interest are also encouraged.
Biological Psychiatry is one of the most selective and highly cited journals in the field of psychiatric neuroscience. It is ranked 4th out of 135 Psychiatry titles and 13th out of 251 Neurosciences titles in the Journal Citations Reports® published by Thomson Reuters. The 2012 Impact Factor score for Biological Psychiatry is 9.247.
Elsevier is a world-leading provider of scientific, technical and medical information products and services. The company works in partnership with the global science and health communities to publish more than 2,000 journals, including The Lancet and Cell, and close to 20,000 book titles, including major reference works from Mosby and Saunders. Elsevier's online solutions include ScienceDirect, Scopus, SciVal, Reaxys, ClinicalKey and Mosby's Suite, which enhance the productivity of science and health professionals, helping research and health care institutions deliver better outcomes more cost-effectively.
A global business headquartered in Amsterdam, Elsevier employs 7,000 people worldwide. The company is part of Reed Elsevier Group plc, a world leading provider of professional information solutions. The group employs more than 30,000 people, including more than 15,000 in North America. Reed Elsevier Group plc is owned equally by two parent companies, Reed Elsevier PLC and Reed Elsevier NV.
Their shares are traded on the London, Amsterdam and New York Stock Exchanges using the following ticker symbols: London: REL; Amsterdam: REN; New York: RUK and ENL.
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.