Brain Chemistry on LSD

I recall one time, quite awhile ago, when I took LSD with 2 friends, it began to take effect in 25 minutes. All of us suddenly began laughing, rolling on the floor, felt like I couldn't stop. I don't know what caused it, but I feel it was likely an immediate contagious, spontaneity. LSD influences serotonin receptors in the brain. Serotonin is a neurotransmitter that plays a role in every part of your body, from your mood, emotions to motor skills & body temperature.

According to one study, LSD causes changes in the brain’s blood flow and electrical activity. The study also suggests it increases areas of communication in the brain. Together, these effects on the brain can result in: impulsiveness, rapid mood changes; -euphoria to fear, a paranoia altered sense of self, hallucinations, synesthesia, [a crossing of the senses], increased blood pressure, to a fast heart rate. It lasted for 12 hours, with a gradual "coming down", as it was called, when the high from the drug begins to feel it is diminishing, often to a depressive state.