Scientists Identify Link Between Heroin and Dopamine

Dr. Kathleen Whaley, a board-certified addiction medicine physician, has cared for patients in a variety of recovery settings, including medication-assisted treatment (MAT), partial hospitalization programs (PHP), and inpatient care. Dr. Kathleen Whaley also maintains active membership in the national and Indiana chapters of the American Society of Addiction Medicine, through which she encounters new developments in her field.

A recent study out of the University of Geneva, Switzerland, has revealed findings indicating dopamine as a contributing factor in the processes of addiction. Dopamine's role in addiction has been debated for a number of years, but the Geneva team has demonstrated its connection with heroin through several mouse model experiments.

One experiment showed that after the team gave heroin to the subject mice, the level of dopamine in the subjects' neural reward center increased significantly. A subsequent experiment involving repeated exposure yielded similar results.

The team then sought to link dopamine with the addiction process itself. In mouse subjects with heroin addictions, which were demonstrated by a tendency to self-administer the drug using a touch lever, the activity of dopamine neurons was inhibited and there was a significant decrease in self-administration of the drug. The link between dopamine release and heroin addiction was solidified with the next experiment, which replaced a laser light addiction with a heroin addiction in mice with manipulated dopamine neurons.

The study's senior author, Professor Christian Lüscher, believes that these findings mark important progress in the effort to understand addiction pathways. According to Dr. Lüscher, with more research, knowledge of these pathways could improve both addiction science and pain management.