Yup yup. My "Bipolar I" started as yet another episode of hardcore depression with (relatively mild) psychosis. I was 23. As the untreated episode progressed, I lost touch with reality and fell into straight up madness, and now I'm diagnosed as either "Schizophrenia w/ a mood disorder" (former docs) or "Bipolar I w/psychotic features" (current treatment people).

Psychotic depression is apparently somewhat common, but not much studied. I've read treatment plans, and if the standard antidepressant+antipsychotic combo doesn't work, they basically throw pills at you. One recommendation involved Ritalin w/ a tricylic and an antipsychotic, all at once, and was based on 4 patients or so. That's psychiatry for you..."science" hasn't yet made a big impact in mental health.