"The symptoms [of ergotism] can be roughly divided into convulsive symptoms and gangrenous symptoms.
"Convulsive symptoms of ergotism
"Convulsive symptoms include painful seizures and spasms, diarrhea, paresthesias, itching, mental effects including mania or psychosis, headaches, nausea and vomiting.
"Gangrenous
"The dry gangrene is a result of vasoconstriction induced by the ergotamine-ergocristine alkaloids of the fungus. It affects the more poorly vascularized distal structures, such as the fingers and toes. Symptoms include desquamation or peeling, weak peripheral pulses, loss of peripheral sensation, edema and ultimately the death and loss of affected tissues..."
LSD
Link:https://www.reddit.com/r/DrugNerds/comments/718biw/real_worl...
*this is not an endorsement.
There is also a common theory that the Salem witch trials were at least in part motivated by ergot, but there is at least a circumstantial case[1] against it.
[0]: https://en.wikipedia.org/wiki/Never_Again_%28The_X-Files%29
[1]: http://www.pbs.org/wnet/secrets/witches-curse-clues-evidence...
The article gets so lost in drawing material correlations that a newcomer to art history would be drawn to overlook the human correlations.