Neurochemistry underlying relapse to opiate seeking behaviour.

Relapse is a major clinical problem and remains a major challenge in the treatment of addictions. A goal of current research is to gain a greater understanding of the neurochemistry underlying relapse to opiate use. Factors which trigger relapse in humans such as stress, exposure to opiates and/or drug-associated cues, can also trigger opiate-seeking in animals. This review will overview preclinical studies relating to the neurochemistry of opiate-seeking with a focus on studies published from 2005 to present.