My husband's BP was diagnosed this way. He had been hospitalized for severe depression and suicidal thoughts. The new anti-depressants they gave his triggered his mania (he'd been depressed for years without any cycling). He was out of the hospital for about 2 months when it happened.

It was scary to watch, I called him from work on my break and he was bawling uncontrollably, so I went home to make sure everything was ok. He was still sad for most of the afternoon, then after dinner, he said he was going to the store. When he came back it was like he'd gone and scored drugs. I'd never seen him that way before, he's always been my mellow man. He was up all night buzzing around. The next day his Dr. yanked him off his meds and diagnosed BP. He was 35 yrs old. VERY uncommon to be diagnosed with BP that late. But his Pdoc is head psychiatry of a major university hospital and has been husbands pdoc for 10 years. Husband has a good trusting relationship with his Dr.

He's had one other obvious rapid-cycle since then, just recently, again because of an anti-depressant. The most recent was worse than the first, he went up and down at least twice. But we knew what was happening and it wasn't as scary.