A Santa Monica Public Library had this on VHS about 25 years ago. I remember enjoying it a great deal. It was one of the first foreign films I'd ever seen (though since I've seen hundreds.)
I remember very few details, and may be mixing up 2 different films, but here's what I have:
It was a Mexican Black & White drama w/ comedic elements from the 1940's or 50's.
There was a father of a somewhat well-to-do family.
The children (grown) are greedy try to get money from father or ensure their inheritance. They may have been talking about his mental state.
His mental state was fine, but he is disappointed with his children. He tries to teach them a lesson. I think he tells them he doesn't have any money for their inheritance.
HERE I MAY BE MIXED UP WITH ANOTHER FILM: Someone (i think it was the father) conducts an electric streetcar / trolley, probably in Mexico City. I think maybe he does this to make his children think he lost his money. I seem to remember he does his disappointed thinking while driving the streetcar.
That's about all I remember.