A new study found the hallucinogenic drug reduces activity in the part of the brain that deals with negative emotions.
Researchers from the University of Basel, Switzerland, measured brain activity in 20 people who took 100 microgrammes of LSD.
Each person looked at photos portraying emotions like anger, joy and fear.
After taking the drug, the participants reacted to fear differently and showed less activity in the amygdala.
This part of the brain is central to processing emotions.
Researchers believe lower amygdala activity is a direct consequence of taking the drug.