Gambling is the wagering of something of value on a random event that has an outcome determined at least in part by chance. This activity can involve a wide range of activities, including sports events, casinos, lottery games, and the use of electronic devices such as slot machines and video poker. While gambling is legal in most countries, it can cause serious problems for some people.

Many individuals with a gambling problem experience significant emotional, social and financial problems. The behavior is characterized by a persistent and recurrent pattern of maladaptive behaviors that result in adverse consequences for the gambler and others. It involves a risky activity that can lead to the loss of money or other valuables, and it is characterized by a compulsive desire to continue gambling even when there are negative consequences. It is a type of behavioral addiction, and about 0.4% to 1.6% of Americans meet diagnostic criteria for pathological gambling (PG) in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV).

Although there are risks associated with gambling, many people enjoy it. The thrill of gambling can trigger the release of dopamine, a neurotransmitter that causes the brain to feel excited and reward-seeking. This chemical response can be addictive and lead to unhealthy gambling habits.

Many people with a gambling problem are vulnerable to developing more severe problems because of their low incomes and the perception that a big win will bring them a better life. Vulnerability is also higher among young people and men. Longitudinal studies are needed to identify a number of factors that may influence the development of gambling problems.