This is a difficult question to answer, because we have little evidence we can turn to about prehistoric recreational use of naturally occurring substances. Even before the fermentation of alcohol, there is no doubt that ancient man would have stumbled along a mushroom or a poppy, or something else, that would have been mind altering. Equally likely that it would have been quickly identified and led to recurrent use. This brief article suggests that stone age man MAY have used drugs based on some archaeological paraphernalia that was discovered, but there is no direct evidence.