It's no surprise that trying out a psychoactive substance can turn you into a different person. New research suggests that even a single bump of cocaine can change the way you act and feel — especially when it comes to negative emotions, reports Motherboard. For the small study, recently published online in the journal European Neuropsychopharmacology, researchers recruited 24 recreational coke users (only five were women). On the first test day, everyone had breakfast, filled out some questionnaires about their mood and sleep habits, took various health tests, and then received cocaine or a placebo powder. At least an hour later, participants had to identify the emotions (including happiness, fear, anger, and disgust) that were shown in 50 pictures of faces. They also took a creativity test and filled out another mood questionnaire. On the second test day, which was at least a week after the first, the procedure was the same except that those who'd gotten cocaine got the placebo this time, and vice versa. The results showed that, when participants had taken cocaine, they had a harder time identifying sadness and anger. In particular, coked-up participants did worse on low-intensity anger and high-intensity sadness identification than they did when they were sober. They could tell when people were extremely angry or a little bit sad, but not when they were seriously sad or a tad angry. While this may not be surprising to anyone who's been around anyone on coke, it does shed some light on the intricacies of that notorious cocaine-induced euphoria. It's not just that users are feeling great; it's also way more difficult for them to identify distinctly not-great emotions in the people around them. This probably makes coke users less-than-super-fun to hang around. Of course, this was a small study, so it's hard to know how generalizable these effects really are. And these changes were just temporary alterations in personality. For long-lasting effects, you might have to try some of the more mind-bending options.