Six months before the start of World War II in 1939, Roland Fischer left Hungary to study chemistry at the University of Basel in Switzerland, where he received his Ph.D. in 1945.

[1][9] Like German chemist Kurt Beringer (1893-1949) before him, Roland Fischer began looking for an explanatory model of psychosis for schizophrenia in the late 1940s by comparing it to altered states produced by hallucinogens.

[11] Fischer explored the model psychosis hypothesis of altered drug states originally studied by Beringer in 1927.

In the 1960s, he helped contribute to research on gustation and is credited with discovering the association between the ability to taste PROP (6-n-propylthiouracil) with food preferences and body weight, and its relationship to alcohol use and smoking.

[15] Between 1968 and the late 1980s, Roland Fischer developed a model for altered states of consciousness in several stages known as the perception-hallucination continuum.