There’s Such a Thing as a Poker Face; Now Research Suggests There Are Poker Brains, Too

We’ve all heard the expression, “He’s got a poker face.” That means that a person’s thoughts and emotions are well hidden behind a mask of inscrutability.

Interestingly, there may also be such a thing as a poker brain.

Or — more accurately — a difference in the opioid systems of pathological gamblers. Such brain anomalies have been documented in cocaine and heroin abusers, as well as alcoholics. A new study, presented at the European College of Neuropsychopathology (ECNP) Congress in Berlin, posits that the opioid systems in the brains of pathological gamblers may be different than their peers, affecting the endorphin system and ultimately altering their control, motivations, emotions, and responses.

Researchers discovered that the opioid systems in people with gambling problems responded differently than those of volunteers not similarly affected. The difference? Compulsive gamblers have reduced feelings of euphoria, which may cause them to keep “chasing the high” that gambling produces.

For the study, “Endogenous Opioid Release in Pathological Gamblers After an Oral Amphetamine Challenge,” researchers took 14 pathological gamblers and 15 healthy recruits, and used PET (Positron Emission Tomography) scans to measure opioid receptor levels in the brains of the two groups. These receptors allow cell to cell communication – they are like a lock with the neurotransmitter or chemical, such as endogenous opioids called endorphins, acting like a key.

The researchers noted there were no differences between the receptor levels in pathological gamblers and non-gamblers, unlike what has been observed about addiction to alcohol, heroin, or cocaine where increases are indeed visible in opioid receptor levels.

“All subjects were then given an amphetamine tablet which releases endorphins, which are natural opiates, in the brain and repeated the PET scan. Such a release – called an ‘endorphin rush’- is also thought to happen with alcohol or with exercise,” according to the published research. “The PET scan showed that the pathological gamblers released less endorphins than non-gambling volunteers and also that this was associated with the amphetamine inducing less euphoria as reported by the volunteers.”

“From our work, we can say two things,” lead researcher Dr. Inge Mick said in a statement. “Firstly, the brains of pathological gamblers respond differently to this stimulation than the brains of healthy volunteers. And secondly, it seems that pathological gamblers just don’t get the same feeling of euphoria as do healthy volunteers. This may go some way to explaining why the gambling becomes an addiction.”

Gambling is no small addiction. Between two and three percent of Americans are addicted to its charms, and the practice eats up at least $5 billion annually. The suffering it causes — both emotional and financial — affects not only pathological gamblers, but also their families and friends.

Researchers hope their findings will lead to new treatments for the ailment of gambling addiction.

“This is the first PET imaging study to look at the involvement of the opioid system in pathological gambling, which is a behavioral addiction,” Mick said. The findings were surprising for Mick, who said that addicts, such as alcoholics, tend to have a higher level of opioid receptors. The findings suggest that the involvement of the opioid system in gambling addiction “may differ from addiction to substances such as alcohol. We hope that in the long run this can help us to develop new approaches to treat pathological gambling.”