Diagnosed MDD at 41, then BP NOS at 53, and finally BP 1 at 55. I'm 59 now. Looking back, I've had symptoms since age 10 or thereabouts, but was never checked out until my internist said I had something that was too much for him to handle and referred me for a psych consult. I was livid at the time but kept the appointment, and the rest, as they say, is history.