The most popular Christmas movie on TV seems to be Miracle on 34th Street (1947). It is being shown over and over, in color and black-and-white. It is an entertaining and corny Santa Claus movie, if you haven't seen it. It has been remade, but you want to watch the original.
The courtroom psychiatry scenes are particularly amusing. Santa Claus calls the psychologist "contemptible, dishonest, selfish, deceitful, vicious -- and yet he's out there and I'm in here. He's called normal and I'm not." The judge has to rule on Santa's sanity, and he is in way over his head.
Another amusing old movie with a courtroom psychiatric commitment scene is Mr. Deeds Goes to Town (1936). Gary Cooper has to deal with greedy relatives, backstabbing lawyers, and schlock forensic psychiatrists. Again, the expert testimony is worse than worthless and you wonder how a court could ever deal with a psychological issue competently.