Going back thousands of years, gambling takes its place in human history as one of the earliest forms of entertainment.When played responsibly, it can be an enjoyable source of entertainment. However, there is a much darker side of this recreational endeavor.For about 4 to 6 percent of those who gamble, gambling becomes a serious compulsion or an out-of-control addiction. Some people turn to gambling to alleviate psychosocial stress or to cope with an emotional problem. Scientists know today that for many people, intrinsic genetic factors are also a contributing cause in the transmission of this disorder.For the past 15 years, addiction scientists have debated about how to classify pathological gambling.In the Diagnostic Standard Manual of the American Psychiatric Association (DSM 5, May 2013), pathological gambling is now included on the list of addictive disorders along with drugs and alcohol, and is called “gambling disorder.”The DSM 5 manual lists the factors that indicate a diagnosis of a gambling disorder. They are useful clinical indicators for mental health practitioners to evaluate and diagnose mental illness.A gambling disorder is characterized by compulsively driven behavior, which the gambler finds very difficult to stop; persistent preoccupation with gambling activities; gambling to alleviate stress; craving gambling when not doing it; and gambling in spite of jeopardizing important relationships, financial savings, career and other vocational activities. The Internet has made gambling so accessible. There are literally hundreds of online gambling sites from all over the world. A click of the mouse and you can start rolling the dice or play blackjack, slot machines or Texas hold ’em. In fact, online gambling is one of the most lucrative businesses on the Internet, bringing in billions of dollars every year.Harry, a 70-year-old childless widower, suffered the loss of his wife from cancer a few years before he was referred to my clinic. He lived alone and had very few friends. He would spend most of his time at home and found comfort in surfing the Internet.One day, Harry accidentally came across an online gambling site. The site was very attractive and he followed the inviting messages, including the one that gave him free money (credit) to try his luck playing poker.During the early years of his marriage, Harry had played poker with friends, so he thought he should try it on line. At first, he told me he had won some money and was happy. This was the most excitement he had felt in a long time. He continued playing, using his credit card to buy more online chips.About three months later, Harry reached his credit limit and maxed out his credit cards, which were canceled.He had spent most of his savings on the online site. Luckily for him, his niece came to visit him once a week. He broke down during a visit and confided to her about what had happened. It was at this point that he agreed to get help.Harry was unaware of how his fragile emotional state made him vulnerable to develop a gambling disorder.After the loss of his wife, his depression and loneliness put him at risk of using gambling to help him escape his emotional pain. Gambling on line, while enticing at first, soon became a maladaptive and self-destructive coping mechanism that he was unable to stop. During the early stage of treatment, I referred Harry to a psychiatrist, who prescribed an anti-depressant to help him with his sadness and depression. Cognitive- behavioral therapy helped him manage the way he looked at his life and begin to develop better coping skills to deal with his loneliness. He also began to attend a 12-step Gamblers Anonymous group that provided him with social interaction, reducing his loneliness, and taught him the stages of recovery from his addiction.AS A rule, it is probably not a good idea to gamble online. But if you must, the addiction literature does make the following suggestions: • If you enjoy gambling and want to do so online, make sure you are not gambling to run away from emotional problems, be they depression, anxiety, anger and/or life crises such as breaking up with a partner, loss of a job or any other life event. Instead of gambling, get some professional counseling.• If you do gamble, set limits on time and money spent.• Play for fun, not just for money.• Bet on what you can afford to lose.• Know when to quit.• Avoid mixing gambling online with alcohol or other substances.• Never borrow to play.• Balance recreational gambling with other healthy activities.• Know when to get help, especially if you find you cannot cut back on gambling.