Digitalis and blue halos around lights), convulsions, and deadly disturbances of the heart. For a case description, see the paper by Lacassie. Vincent van Gogh's "Yellow Period" may have been influenced by digitalis therapy which, at the time, was thought to control seizures. As noted above, other oculotoxic effects of digitalis include generalized blurry vision, as well as seeing a "halo" around each point of light. In some instances, people have confused digitalis with the relatively harmless comfrey ("Symphytum") plant, which is often brewed into a tea, with fatal consequences. Other fatal accidents involve children drinking the water in a vase
Recreational drug use part of the milieu of drug taking. The reasons for drug use appear to have as much to do with needs for friendship, pleasure and status as they do with unhappiness or poverty. Becoming a drug taker, to many people, is a positive affirmation rather than a negative experience.” Anthropological research has suggested that humans "may have evolved to counter-exploit plant neurotoxins". The ability to use botanical chemicals to serve the function of endogenous neurotransmitters may have improved survival rates, conferring an evolutionary advantage. A typically restrictive prehistoric diet may have emphasised the apparent benefit of consuming psychoactive drugs, which