Individuals who have an alcohol addiction often relapse over and over again after receiving initial substance abuse treatment. One reason that alcoholism is difficult to overcome is that the cues that lead to alcohol consumption often turn up in unexpected places.

A new study says that those cues can even appear in the form of smells, making it very difficult for someone working to abstain from alcohol. The study, conducted by researchers at Indiana University was led by Jessica Wilden, from the university’s neurosurgery department.

The study focused on testing the effects seen in the brain when rats are exposed to certain cues, such as a smell, that they associate with alcohol consumption. The results of the study show that there may be a physical neurological basis for the cravings and relapse that are associated with alcohol consumption.

The researchers found that a specific area of the brain called the basolateral amygdale exhibited increases in activity at times when the animal models were exposed to smells that they had been conditioned to relate to alcohol. The amygdale, a structure in the brain that is shaped like an almond, is involved with motivation and emotion functions.

The researchers exposed alcohol-preferring rats to an environment that either had alcohol or did not, and provided alternative smells that the rats were trained to associated with the existence or lack of alcohol. The alternative odors were not connected with alcohol, but were instead such odors as anise (licorice), peppermint and orange.

Primary investigator Zachary Rodd is an associate professor of psychiatry. Rodd explains that addiction contains an aspect of learning. Those who use addictive substances have a ritual that goes with that behavior. Before long, there is a group of cues, any of which can lead to a craving. Relapse, says Rodd, may be closely linked with these cues that have, in the past, been associated with substance use that stimulate cravings.

The study showed that in the rats were introduced to craving-inducing cues, there was measurably more activity in the basolateral amygdale when compared with other brain regions. In addition, when the researchers used drugs to deactivate the basolateral amygdale, the rats exhibited a decrease in cravings.

Wilden explains that the study shows that a very precise region in the brain is responsible for controlling a very precise behavior and response. This leads experts to understand substance abuse relapse as a physical challenge that may require physical treatment.

In addition, the study’s findings show that the functions of the brain responsible for cravings and those responsible for inhibiting the craving are in different areas of the brain.

The study provides evidence that supports the development of specific therapies designed to impact the basolateral amygdale, with a goal in mind of helping control cravings for substances such as alcohol and drugs.