From the WUSTL Newsroom…
New research may help explain why drug treatments for addiction and depression don’t work for some patients.
The conditions are linked to reward and aversion responses in the brain. Working in mice, researchers at Washington University School of Medicine in St. Louis have discovered brain pathways linked to reward and aversion behaviors are in such close proximity that they unintentionally could be activated at the same time.
The findings suggest that drug treatments for addiction and depression simultaneously may stimulate reward and aversion responses, resulting in a net effect of zero in some patients.
The research is published online Sept. 2 in the journal Neuron.
“We studied the neurons that cause activation of kappa opioid receptors, which are involved in every kind of addiction — alcohol, nicotine, cocaine, heroin, methamphetamine,” said principal investigator Michael R. Bruchas, PhD, associate professor of anesthesiology and neurobiology. “We produced opposite reward and aversion behaviors by activating neuronal populations located very near one another. This might help explain why drug treatments for addiction don’t always work — they could be working in these two regions at the same time and canceling out any effects.”
Addiction can result when a drug temporarily produces a reward response in the brain that, once it wears off, prompts an aversion response that creates an urge for more drugs.
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