Ancient humans were getting high on hallucinogenic drugs during cave rituals 3,000 years ago, study claims

• Scientists have discovered the use of hallucinogenic drugs by humans 3,000 years ago.
• They believe shamans used drugs as part of rituals held at the Es Càrritx cave in Menorca.
• Previous evidence of ancient drug use had been indirect and largely based on depictions in art.

Ancient humans were getting high on hallucinogenic drugs during cave rituals 3,000 years ago, according to a new study. 

Researchers made the discovery after studying Bronze Age strands of hair found in the Es Càrritx cave on the Spanish island of Menorca.

The cave was first occupied around 3,600 years ago, and was used as a funeral space until around 2,800 years ago, the researchers said.

The study, published the journal Scientific Reports, found psychoactive substances atropine, scopolamine and ephedrine on hair strands, which had been dyed red. 

The drugs would have induced delirium, causing symptoms such as extreme mental confusion and "strong and realistic hallucinations."

The scientists believe the substances, likely derived from various plants, were used as part of rituals held at the cave.  These may have involved shamans "who were capable of controlling the side-effects of the plant drugs", per the study.

The strands of hair had been placed in wooden and horn containers decorated with concentric circles.

"The concentric circles on the wooden containers may have depicted eyes and could have been a metaphor for inner vision related to a drug-induced altered state of consciousness," according the press release. 

"As preserved human hair is rare in archaeological contexts, this was an unusual opportunity to detect levels of drugs in biological samples," Elisa Guerra-Doce, an associate professor of prehistory at the University of Valladolid told Motherboard. 

Previous evidence of drug use by ancient humans had been indirect and largely based on depictions in art.