Yes, in the US the police can take you into the hospital for a 72 hour hold if the doctor (doesn't have to be a psychiatrist) agrees. For more than time than that a psychiatrist has to take you to court (police actually physically take you to the court). You stay until the psychiatrist agrees you are not a danger to yourself or others, but you have to go back to court to be released. You cannot be forced to take medicine unless the court requires it.