Addiction, Author Interviews, Methamphetamine / 13.02.2015 Interview with: Kyoon Lyoo, M.D., Ph.D Ewha W. University Seoul, South Korea MedicalResearch: What is the background for this study? What are the main findings? Dr. Lyoo: Recent studies increasingly suggested that the developing brain shows unique characteristics of neuroplasticity to environmental stimuli. Still, it remains unclear whether the adolescent brain would undergo adaptive or dysfunctional changes when exposed to highly neurotoxic substances including methamphetamine. However, despite an increasing prevalence of methamphetamine use in this population, human studies have not yet found clear answers to these questions regarding the effects of methamphetamine exposure on the adolescent brain. This study reports novel in vivo findings in adolescent methamphetamine users, and thus provides a new perspective regarding adolescent-specific brain correlates of methamphetamine-induced neurotoxicity. Using cortical thickness and diffusion tensor image analyses, we found greater and more widespread gray and white matter alterations, particularly affecting the frontostriatal system, in adolescent methamphetamine users compared with adult users. Our findings highlight that the adolescent brain, which undergoes active myelination and maturation, is much more vulnerable to methamphetamine-induced neurotoxicity than the adult brain. This may help explain why adolescent-onset methamphetamine users show more severe and chronic clinical course than adult-onset users. (more…)
Addiction, Author Interviews, JAMA, Neurological Disorders / 28.05.2014 Interview with Dr. Edythe  D.London PhD Professor, Departments of Psychiatry and Biobehavioral Sciences, and Molecular and Medical Pharmacology David Geffen School of Medicine, UCLA Dr. Edythe  D.London PhD Professor, Departments of Psychiatry and Biobehavioral Sciences, and Molecular and Medical Pharmacology David Geffen School of Medicine, UCLA MedicalResearch: What are the main findings of the study? Dr. London: Brain function related to risky decision-making was different in stimulant users  (methamphetamine users) than in healthy control subjects. In healthy controls, activation in the prefrontal cortex (right dorsolateral prefrontal cortex) during risk-taking in the laboratory was sensitive to the level of risk. This sensitivity of cortical activation was weaker in stimulant users, who instead had a stronger sensitivity of striatum activation. The groups also differed in circuit-level activity (network activity) when they were not performing a task but were “at rest.”  Stimulant users showed greater connectivity within the mesocorticolimbic system, a target of abused drugs. This connectivity was negatively related to sensitivity in the prefrontal cortex to risk during risky decision-making. In healthy control subjects, connectivity between the right dorsolateral prefrontal cortex and striatum was positively related to sensitivity of prefrontal cortical activation to risk during risky decision-making. (more…)
Addiction, Author Interviews, Memory, Methamphetamine, Scripps / 11.09.2013 Interview with: Ph.D., Neurobiology & Behavior and Center for the Neurobiology of Learning & Memory (2005), University of California, Irvine, CaliforniaCourtney A. Miller, PhD Assistant Professor Department of Metabolism & Aging Department of Neuroscience The Scripps Research Institute Jupiter, FL 33458 What are the main findings of the study? Dr. Miller: The relapse rate for drug abusers, smokers and alcoholics is high because abstinence is so difficult. A major factor is the craving that drug associations can trigger. These range from seeing the neighborhood where someone used to buy, in the case of illicit drugs, to social drinking for a smoker. We’ve found a way to disrupt these drug-associated memories without affecting other, more benign memories. (more…)