A new study may end the century-old controversy over what ingredient in absinthe caused the exotic green aperitif’s supposed mind-altering effects and toxic side-effects when consumed to excess. In the most comprehensive analysis of old bottles of original absinthe — once quaffed by the likes of van Gogh, Degas, Toulouse-Lautrec and Picasso to enhance their creativity — a team of scientists from Europe and the United States have concluded the culprit was plain and simple: