GENEVA (AP) — People may have been getting high off cannabis earlier than previously thought — at least 2,800 years ago, a new study suggests.

Archaeologists who led a dig at a monumental tomb in Siberia said they turned up evidence of the earliest known use of cannabis for psychoactive purposes.

The findings point to cannabis consumption at least 300 years earlier than previously known use in neighboring China.

Ancient drug use has long intrigued scholars. The Greek historian Herodotus wrote about inhabitants of Central Asia smoking cannabis around 440 B.C., and recent archaeologists have found the seeds in tombs across its highlands.

The team from Germany, Russia, Sweden and Switzerland said analysis of hair in the royal tomb where cannabis seeds turned up sheds new light on the plant’s role in ancient societies.