Researchers say that about one third of all people who use indoor tanning beds become addicted to the practice. These people are also more likely to suffer from anxiety and more prone to abuse alcohol and drugs. Some research suggests that exposure to ultraviolet radiation from indoor tanning beds releases endorphins, chemicals in the body that improve mood, so tanners may be using the beds as a way to cope with distressing emotions. Addressing underlying issues may help tanning addicts reduce their use of sunbeds.