I'm pretty certain my bipolar disorder started at around 14, but I wasn't officially diagnosed for 18 years, at age 32. I had ended up at doctors' offices (mostly GPs, but a few psychiatrists) several times before my diagnosis with complaints of anxiety, depression, and likely milder mixed episodes. They'd prescribe an antidepressant and/or antianxiety med, which I'd take for two to max 14 days, then stop. I never had follow-up appointments set. I'd only see some again when depression/anxiety/mixed symptoms returned again. Never during purer mania or hypomanias, despite occasional ramifications from them. I never felt I received any actual diagnosis. I looked at my visits to those doctors as quick help for "mental flues". At 14, I was sent to a child therapist. I told my parents I wanted to quit it after the second session. They allowed that. I have no idea what that therapist thought. Teenage strife/angst? I remember hating it because when my dad attended, he always boo-hooed about his own situation, and how I was worsening it.

Once I finally started seeing a psychiatrist for more than a few appointments, they finally saw my mood switch. I didn't accept the diagnosis at first. It took hospitalizations for that. Many many psychiatrists and therapists reconfirmed my diagnosis over the years. Increased insight and knowledge about bipolar disorder allowed me to confirm it with myself. But I fought a lot in the early years, often thinking I could fight/control it on my own. I couldn't.