I think I might have heard voices for a short time at 15 and maybe 21, but despite brief therapy (at 15) and a one-off visit to my university psychiatrist (referred by the university health center) I wasn't given a bipolar or any diagnosis to my knowledge. During my 20s I had 3 bad depressions and probably one full mania, but many long-term hypomanias. I saw GPs after that a few times for anxiety and depression, but they treated me incorrectly. I'd stop an antidepressant after days or a week because of mood switches. Then finally a GP referred me to my first serious psychiatrist, who diagnosed me with bipolar 2 after personally witnessing a hypomania. I quit him that day and didn't take the moodstabilizer he recommended.

It was only in my mid 30s that I had a string of severe manias with psychosis leading to hospitalizations and my bipolar 1 diagnosis. I think that years of being unmedicated, severe stressors, and alcohol abuse (likely self-medication) worsened my course. Three years of severe manias (often mixed) led to my worst depressions, one starting mixed with psychosis, ending as a pure depression without psychosis.

Though I had mood episodes since, I've only reached full blown mania two additional times, both with psychosis. Luckily my psychiatrist handled them outpatient. I've also had a few depressions, but relatively short-lived.

I, personally, have only become psychotic when manic or manic or depressed with mixed features. Never during pure depressions. Obviously, never during hypomanias since that's not possible unless from another cause (schizoaffective disorder, drug induced, physical, or other).