Benzodiazepine is a type of CNS depressant prescribed to relieve anxiety and sleep problems. Valium and Xanax are among the most widely prescribed medications.
Since their introduction in the 1960s, drugs categorized as benzodiazepines, which include diazepam (Valium) and alprazolam (Xanax), have been widely prescribed to treat anxiety and insomnia, alcohol withdrawal, and other conditions. Although they are highly effective for their intended uses, these medications must be prescribed with caution because they can be addictive. Now, work by NIDA-funded researchers has established that benzodiazepines cause addiction in a way similar to that of opioids, cannabinoids, and the club drug gamma-hydroxybutyrate (GHB). The discovery opens the door to designing new benzodiazepines that counteract anxiety but are not addictive.
The pleasurable sensations that make addictive drugs disastrously attractive for vulnerable individuals occur when dopamine levels in the brain’s reward area abruptly surge. Researchers had worked out how most addictive drugs, but not benzodiazepines, precipitate these surges. Dr. Lüscher and colleagues have now demonstrated that benzodiazepines weaken the influence of a group of cells, called inhibitory interneurons, in the brain’s ventral tegmental area (VTA). These neurons normally help prevent excessive dopamine levels by downregulating the firing rates of dopamine-producing neurons. Two negatives make a positive, so when benzodiazepines limit the interneurons’ restraining influence, the dopamine-producing neurons release more dopamine.
Brown, M.T.C., et al. Drug-driven AMPA receptor redistribution mimicked by selective dopamine neuron stimulation. PLoS One. 5:12: e15870, 2010. Full Text Available (PDF,2.2MB)
Riegel, A.C., and Kalivas, P.W. Neuroscience: Lack of inhibition leads to abuse. Nature 463: 743–744, 2010. Abstract Available