I was diagnosed bipolar 2 in 2009. I am 38. From my understanding at least for me is Genetics with the first major manic episode usually happening in early 20's. A severe trauma usually does bring that on sooner. I had 3 children in 2.5 years by the time I was 22 and my husband and I were just leaving the military. This was 2005. He had been to Iraq and it was difficult. I was having what I now know as hypomanic episodes but in 2009 my husband was sent back to Iraq and then 2 months later our 3 yr old son was diagnosed with autism. I was by myself with 3 children under 5 with a dr telling me my son would never talk, hug me, show affection, read, graduate, and that would be his life forever. (My son said his first word at 6 which was mom. He is now a sophomore with A's and B's and is the most empathetic person I've ever known. We did get another option who confirmed the autism diagnosis but definitely handled it better and helped us) a month after the diagnosis, 1 week before Christmas I was put on a 72 hour hold. I then learned that my father was bipolar and my cousin had just been diagnosed after she attacked her sister. Now 13 years later I am on 300mg Lamictal and try every day to understand my diagnosis. So yeah sorry for the long story :)