Over the next half century, although other supportive nutrients have been discovered, orthomolecular physicians and researchers have continued to find megadose vitamin B3 and megadose vitamin C to be major therapeutic agents for most adult psychoses,* including manic and depressive psychoses. This applies to all biotypes, even histadelia (more on biotypes later).
That is, niacin and C, within the context of a complex of indicated nutrients, health therapies, and other treatments, as per individual biochemical requirements, including contraindications.
For references, consult the literature, and see my books, Natural Healing for Schizophrenia and Natural Healing for Bipolar Disorder.
* Some exceptions: for pyrolurics and for young people, B6 or B6 plus B3, may often be more effective than B3 alone.