Drug addicts escape from stress or aversive life effects through drug use, said Robert Wheeler, an assistant professor in the biomedical sciences department, while presenting his research Tuesday in Schroeder Complex.

Wheeler’s research focused on behavior and its effects on animals in relation to substance abusers. His goal was to discover the motivation behind cocaine addiction.

“My research focuses on examining how such mood states are processed in the brain, and, just as importantly, how they influence animal behavior,” Wheeler said in an email. “This is most relevant to the field of drug addiction, as substance abusers often report that (despite their best efforts) they fail to stay away from drugs of abuse because of stress or aversive life events.”

According to the National Institute on Drug Abuse, in 2007 illicit drugs cost the health care system some $11 billion, and they cost the U.S. $193 billion overall.

Wheeler studies the effects of bad moods in animals and uses the results as a predictor of addictive behaviors.

“This is very important work in terms of understanding both negative and positive reward and is critical to defining the mechanism by which this system is altered in the addiction process,” Wheeler said. “The implications are enormous – not only for the treatment of drug and alcohol addiction, but also for gambling, shopping, sex, eating, gaming – anything capable of becoming addicting.”

William E. Cullinan, dean of the College of Health Sciences and director of the Integrative Neuroscience Research Center, said Wheeler is using a state-of-the-art approach to discover key elements of the brain’s motivational and reward pathways.

Cullinan said it is possibly the case that the reward circuitry of the brain is altered in ways that are different for every neuropsychiatric disorder.

He said an example of this would be mood disorders and how they affect something major like a depressive disorder, where stimuli often lose their rewarding properties.

“In this important sense, Bob Wheeler’s research program sits at the intersection of those of some eight or nine of his neuroscience faculty colleagues within the biomedical sciences department at Marquette,” Cullinan said. “Collectively this group is poised to make great strides in unraveling a series of related disorders involving faulty regulation of the reward circuitry.” 

Wheeler said he was drawn to the field of neuroscience research because he always had an interest in what motivates people and how people’s emotional states, positive or negative, influence their choices.

Wheeler said he plans to continue to study the neural circuitry that underlies negative emotional states. He said he hopes a better comprehension of this system will allow him to address all the causes of relapse in addicts.