Several recent studies are shedding light on why athletes may be more prone than the general population to substance abuse, eating disorders and suicide. The findings may have implications for athletes retiring after the Summer Olympics, Bloomberg Businessweek reports.

Research indicates that intensive exercise can be as addictive as heroin, which puts retiring Olympic athletes at risk of depression, according to the article. A study published in March found one-third of elite athletes have an unhealthy preoccupation with training. Another recent study, conducted in rats, suggests the biological mechanisms of exercise dependence tend to mimic those involved in drug addiction.

The studies suggest retiring athletes might need help adjusting after years spent training nonstop.

“A lot of retired athletes report fairly significant mental health concerns and an increased level of substance dependence,” said Frances Quirk, Co-Editor-in-Chief of the journal Performance Enhancement & Health. “There are other factors that contribute to that in terms of pressure, isolation and competition, but there is a biological story.”

Until recently, scientists have not understood the degree to which reducing training can lead to drug-like withdrawal symptoms in athletes, the article notes.