A study presented in Berlin found the opioid center of the brain works different in people with an addiction to gambling than with volunteers. The article presents the facts pretty plainly, but the implications back up two other observations. First, people are just different, and some can gamble without danger of becoming addicted, but others really can’t. Second, gambling addicts respond better to being treated as if they had a substance addiction rather than psychological addiction. If the problem gambler’s real issue was they were addicted to endorphin rushes, which are only released when gambling, that would explain the success of treating gambling addiction the same as other substance addictions.