A bipolar in manic phase will get hostile with anyone who tries to interfere or slow them down. Reason has fled the building. Here in Alberta, two doctor's opinions, or dangerous behavior can get a person locked up against their will. I used one doctor's opinion and my testimony before a judge to get my mom committed. I simply described some of her extreme behavior in the past month. Like I say, she was out in a month but she never went off her meds again.
In her manic phase, mom was buying goods for strangers on the street.
My son, Schizophrenic, I got him committed by convincing him to go to the emergency to get his cut thumb looked at. As he explained his problems to the intake nurse including the invisible robots, I made cuckoo signals behind his back. He was mad at me for about 48 hours, and then started to appreciate the peace of mind the mental ward offered him. He was in for a month and then settled in a group home. He also never went off his meds again.