Cocaine: How addiction develops / EurekAlert, 21 August 2008
http://www.eurekalert.org/pub_releases/2008-08/haog-cha082108.php
"Permanent drug seeking and relapse after renewed drug administration are typical behavioral patterns of addiction. Molecular changes at the connection points in the brain's reward center are directly responsible for this. This finding was published by a research team from the Institute of Mental Health (ZI) in Mannheim, the German Cancer Research Center (DKFZ) in Heidelberg and the University of Geneva, Switzerland, in the latest issue of Neuron. The results provide researchers with new approaches in the medical treatment of drug addiction."