Gambling involves wagering something of value on an activity that is largely determined by chance with the aim of winning something else of value. It is a popular pastime in most countries, and it contributes to the economic stability of some economies. However, a significant proportion of gamblers develop problems that cause substantial and long-lasting harm to themselves and their families. The most serious problem is gambling disorder, a mental health condition that affects people of all ages and is listed in the Diagnostic and Statistical Manual of Mental Disorders. Some individuals, especially those who have a mental illness, may be particularly susceptible to developing gambling disorders.

Most studies of gambling focus on its negative impacts, such as financial losses to gamblers and their families. However, it is also important to understand the positive aspects of gambling. These include recreational benefits, social connections, and a sense of accomplishment. Some forms of gambling are also a source of revenue for community and charitable organisations, and government revenues derived from gambling can be used to pay for public services. In this way, gambling can have positive as well as negative social and environmental consequences.

Although most individuals who engage in gambling do so for enjoyment, some people become seriously involved and begin to gamble excessively, despite the negative personal, family, and financial effects of this behaviour. This group is considered to be at risk of developing a gambling problem, and these individuals often display many characteristic features, including:

Those who are most at risk for developing a gambling disorder include young people, those with low incomes, and men. Approximately 5% of adolescents and 20% of adults with a mental illness have a gambling disorder, and the number is growing. Young people are the fastest-growing group of gamblers, and they tend to start gambling much younger than previous generations. In addition, many video games include loot boxes that are similar to gambling machines and can be a major source of gambling for young people.

Research into the causes of gambling problems is ongoing, and a number of factors have been identified as contributing to the development of gambling disorders. Some of these factors include:

A defining feature of gambling is that it is inherently risky, and people who gamble are aware that they could lose more than they win. Nevertheless, some people find it difficult to stop gambling, even when they have lost considerable amounts of money, and this can lead to debt and other severe problems.

Many studies of gambling have focused on its costs and benefits, and researchers have used various methodologies to calculate the values of these impacts. For example, a common approach has been to use monetary health-related quality of life weights, which are commonly employed in drug and alcohol studies. However, these measures have a tendency to overestimate the costs of gambling and understate the benefits. In addition, they do not take into account the impact of non-monetary harms or benefits.