People can become addicted to gambling in the same way they become hooked on drugs. The brain releases dopamine—a neurotransmitter that produces a mood boost—when risk is involved. As with drug addiction, people gamble to elevate dopamine levels.
In one study, monkeys were shown various images, each correlated with a different likelihood of receiving a reward—a taste of juice. Some pictures guaranteed a reward, others produced a reward only half the time. The researchers found that when there was only a 50-50 chance of receiving juice, dopamine levels soared.
Further research may help researchers find a way to break the cycle of addiction in both gamblers and drug addicts.