A Single Bump of Coke Makes It Harder to Tell When You're Being 'That Guy'

Doing just one dose of cocaine makes it harder for you to tell when your friends are angry or disgusted with you, a new study has found.

Researchers from the Netherlands and Germany found that cocaine users might feel more sociable when intoxicated simply because they lose the ability to recognize negative emotions.

For the study, which was published in the journal European Neuropsychopharmacology today, researchers gave 24 recreational drug users one 300 milligram dose of cocaine each. They found that an hour later, users were less able to perceive negative emotions than the placebo group. The drug also increased users' heart rate and cortisol levels, which plays a role in emotion processing.

Dr. Michael Bloomfield of University College, London said on behalf of European Neuropsychopharmacology the study shows cocaine may impede the brain's ability to recognize others' emotions in a manner similar to some mental illnesses.

"Since cocaine changes the level of the brain chemical dopamine, this new study may have implications for other mental illnesses such as depression and schizophrenia—where dopamine may also be involved in how we recognize emotions," he said.

The study, which its authors claim is the first to examine the short-term effect of cocaine on emotions, found users' ability to perceive anger and disgust leveled out with the placebo group when the emotions were high intensity, but still made sadness more difficult to recognize.

The researchers said in the future they hope to conduct the study, which included five men and 19 women, with more equal gender distribution and a wider range of empathy measures. The study also raised the question of whether cocaine affects drug users' ability to understand emotions even when they are not high on the drug.

"We know that cocaine is a powerful and addictive drug and an important question remains: does cocaine mess up this process so that when cocaine users are off the drug they feel like other people have more negative emotions?" Bloomfield said.