Gambling is an activity that involves risking money or something of value on an event whose outcome depends partly on chance. It’s also an international business, with an estimated total legal gambling market of $335 billion in 2009 (see Figure below). People might gamble using cash, scratchcards, video games or virtual currency such as coins in online poker or virtual goods in video game worlds like Second Life. Some states have legalized the activity while others have banned it or regulate it. Many people with gambling disorder also have a substance use problem or a mental health condition such as depression or anxiety.

People with gambling disorders can experience problems at work or school, in their families and relationships and with their finances. They may even be at risk of homelessness or suicide. Gambling can be addictive for anyone who is vulnerable, but research suggests that some groups are more susceptible to developing a problem than others. Among them are young people, particularly men, people with low incomes and those who have other addictions or medical conditions. Up to 7% of people with a psychiatric condition, such as schizophrenia or bipolar disorder, have gambling disorder, and about 4% of those who are treated for alcohol use disorders have the condition.

While most adults and adolescents have placed some type of bet, a small number develop a gambling disorder, described in the Diagnostic and Statistical Manual of Mental Disorders as an uncontrollable urge to bet money or other items on an uncertain event with the hope of winning. Several other disorders can be associated with gambling, including depression and anxiety, bipolar disorder, attention-deficit/hyperactivity disorder and post-traumatic stress disorder.

Symptoms of gambling disorder include repeated unsuccessful attempts to control or cut back on gambling, lying to conceal the extent of involvement in gambling, frequent feelings of anxiety and depression and spending more and more time at casinos and other gambling venues. Other symptoms might include chasing losses, spending more than you can afford to lose and spending money on gambling-related activities even when you are poor.

Those with a gambling disorder can seek treatment for the problem, which is usually psychotherapy or counseling. The treatment can slowly help to reverse the changes in parts of the brain involved in reward and excitement. Different approaches may be better for different individuals. For example, some people benefit from cognitive behavioral therapy and psychodynamic therapy, while others find help through family or marriage therapy. Some patients are helped by joining a peer support group such as Gamblers Anonymous, which follows a model similar to Alcoholics Anonymous. Some people also find support from a sponsor, a former gambler who has experienced remaining free from the habit and can offer guidance and support. Medications aren’t used to treat gambling disorders directly, but some medications can improve mental health or substance use disorders that co-occur with the problem. Gambling can cause changes in brain pathways involved in processing reward and risk information and controlling impulsive behavior.