A new study on social media use found that people who spent excessive time on Facebook also made riskier decisions -- performing as poorly in a famous psychological test as people dependent on substances such as cocaine or heroin. 

Researchers at Michigan State University and Monash University in Australia  gave 71 people the the Iowa Gambling Task, which psychologists say identifies the differences in decision-making among healthy people and substance abusers.

When playing the computer simulation of a card game, people who reported they overindulged in Facebook made big gambles at a higher rate -- even when they saw that taking risks in the game always came with big punishments. They played the game the exact way drug addicts typically do, while people who reported less time on social media made better decisions.