SANDIE RINALDO: Football season is now fully underway on both sides of the border. And whenever you have pro football there is one thing you can bet on, people will wager on the outcome of the games. And as the scope of betting grows, so do the problems that come with it. But scientists are now discovering that gambling addictions may have a biological basis. CTV's medical specialist Avis Favaro explains.
AVIS FAVARO (Reporter): Most people can visit a casino, bet on sports or buy lottery tickets without a problem. But for some, gambling becomes a potent addiction.
UNIDENTIFIED MAN: I would say that there's nothing that matches how I feel when I'm gambling. Nothing. There's, sex is, doesn't match the high when you're gambling.
FAVARO: The explosion of gambling venues has helped make obsessive wagering a growing problem across North America, with as many as two percent of adults now considered pathological gamblers.
NIGEL TURNER (Centre for Addiction and Mental Health): It's related to other addictions like alcoholism and tobacco addiction. It's a consequence of doing something too often that changes the way your brain works.
FAVARO: Once seen as a moral weakness, science has labelled compulsive gambling as a psychiatric disorder, because researchers are finding something is different in the brains of people who can't control their gambling.
UNIDENTIFIED MAN: I'm going to move you back into the scanner.
FAVARO: These US researchers scanned the brains of gambling addicts and found differences in the frontal lobes of their brains.
UNIDENTIFIED MAN: The person with a gambling disorder has a little bit less blood flow to this portion of their frontal lobe than does the person without the gambling disorder.
TURNER: To some extent, gambling itself rewrites the brain. You have, whenever you do something that's very stimulating, very rewarding, such as experience a very large win, you are changing the way your brain works.
FAVARO: These addictions can be successfully treated with counselling and support groups, and more recently researchers have found that a drug called Nalathene, used to treat alcoholism, may interfere with circuits in the brain that process pleasure and reward, taking the thrill out of winning. But any drug still has to be used with traditional therapy, because while gambling addictions may have root in the brain, addicts also need help rebuilding often shattered lives.