Wife has paranoid delusions

A letter to Dear Abby describes a woman with paranoid delusions about intruders in the house. She gets her 11-year-old daughter paranoid as well, and nags her husband to death about it. Her husband tries to make light of the situation, or deflect the blame. Dear Abby advises:

DEAR COWARDLY: Your husband's behavior is cruel and unwise. He's encouraging your daughter's fears as a way of punishing you for your forgetfulness. If it continues, your daughter will have phobias that could last a lifetime; it's mental cruelty.

I'm not sure who is nuttier -- Dear Abby or the letter writer. If my wife announced that she heard a strange noise and that there must be an intruder in the house, I might take her seriously the first five times or so. I would eventually decide that my wife suffers from paranoid delusions.