There is some significant evidence that some nutritional supplements and therapy helps with schizophrenia but its not with Dr. Hoffer’s vitamins he researched (from what researchers tell us now). We have a page on Complementary therapies here: Vitamins and Complementary and Natural Treatments - Schizophrenia.com
Unfortunately the work that Dr. Hoffer did was never able to be duplicated by other scientists. Back in the 1970s people tried but could not duplicate his vitamin C, Niacin, etc. research that in early tests he thought showed potential to help people. People later found many problems with his original work.
We cover the review of that research here:
Vitamins and Complementary and Natural Treatments - Schizophrenia.com