New research presented at the European College of Neuropsychopharmacology Congress in Berlin sheds light on what happens in the brains of gamblers.
Pathological gambling is a difficult condition to classify. Though the Diagnostic and Statistical Manual of Mental Disorders (DSM) formerly classified it as an impulse control disorder, the most recent version, the DSM-5, made the switch to defining it as an addictive disorder because of the growing research finding that "gambling disorder is similar to substance-related disorders in clinical expression, brain origin, comorbidity, physiology, and treatment," the DSM website says.
But this new small study shows that it might be unique in some neurologic ways, too. Researchers performed Positron Emission Tomography (PET) scans on 14 male pathological gamblers and 15 non-gambling volunteers to measure their levels of opioid receptors, the parts of the brain activated by pleasure-inducing endorphins. People with addictions like alcoholism or drug addiction have been found to have more opioid receptors. In problem gamblers, however, the researchers saw no difference from healthy volunteers, a finding that surprised them.
Then, participants took an amphetamine capsule, which unleashes endorphins with similar effects to the rush you get from exercise or alcohol, the study says. An additional PET scan revealed that pathological gamblers responded differently to the drug. They released fewer endorphins than those who didn’t gamble, and they also reported lower levels of euphoria on a questionnaire afterward. This might help explain the addictive part of pathological gambling: to get pleasure from the act, problem gamblers might need more of it or to work harder for it.
“ These findings suggest the involvement of the opioid system in pathological gambling and that it may differ from addiction to substances such as alcohol,” says lead researcher Dr. Inge Mick of the Imperial College London in a press release. “We hope that in the long run this can help us to develop new approaches to treat pathological gambling."