Gambling involves the risking of something of value (like money or items) on a game of chance, with awareness that there is a risk involved. It ranges from the purchase of lottery tickets by people with little, to the sophisticated casino gambling of the wealthy. It may be legal or illegal and can involve organised crime. People gamble for a variety of reasons: for social reasons, for financial gain or for the thrill or excitement. It’s also often used as an escape or to relieve stress and anxiety.

Gamblers are often influenced by the principle of partial reinforcement. This means that the behaviour they take isn’t rewarded 100% of the time and doesn’t cause a negative outcome 100% of the time, so they expect to be reinforced some of the time. For example, if they win a few times in a row, they might feel more confident about their ability to win in the future, which motivates them to keep playing.

In the past, the psychiatric community largely regarded pathological gambling as a compulsion rather than an addiction, but in 2013, the American Psychiatric Association moved it to the Addictions section of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). This move is based on evidence that shows gambling can change a person’s brain to look like that of someone with substance addiction.

People who become addicted to gambling may experience a number of psychological symptoms, such as being secretive about their gambling or lying to family and friends. They might also feel compelled to bet more money than they can afford to lose, in order to try and ‘win back’ their losses. They may be overly sensitive to the loss of money and feel a greater emotional response to losing a small amount than they do to finding it, which can lead to them getting into debt.