In the 1990s , hallucinogens and their effects on human consciousness were again the subject of scientific study , particularly in Europe .
Since 2001 , six EU countries have tightened their legislation on psilocybin mushrooms in response to concerns about their prevalence and increasing usage .
In the 1990s , hallucinogens and their effects on human consciousness were again the subject of scientific study , particularly in EU .
Since 2001 , six EU countries have tightened their legislation on psilocybin mushrooms in response to concerns about their prevalence and increasing usage .