Your husband has obvious dementia symptoms, somewhat consistent with one of the less common, younger onset dementias called frontal temporal dementia (FTD). His ability "to fool" the testers is typical before the appointment or at least when your husband is not present. If it is FTD, it is a very tough diagnosis and perhaps the toughest on families. The unpredictable Jekyll and Hyde behavior and his lack of judgment pose real safety risks for both of you. Don't give up on getting a diagnosis and finding a psychiatrist or memory disorders specialist who will work with you. Remember, if he does have FTD or a dementia diagnosis, he is behaving in ways he wouldn't normally choose. His statements are untrue not to spite you, but because he can't think, reason or control his behavior as he has in the past. You will have to learn to work around him, rather than confront him and ask him to change.
of people with FTD. First, ask yourself if this is a significant change from the person he was (when he wasn't depressed). People with FTD initially have less noticeable memory complaints, and more prominent changes in personality, mood, behavior, insight, judgment and empathy (his ability to understand your feelings). His MRI would suggest a frontal problem which could be an atypical depression, but regardless, it will affect his "executive function" or ability to plan and carry out wise personal or financial decisions. He may have recent onset of addictive or compulsive behaviors or he may seem to have lost inhibition or his social censor which reminds him what is appropriate public behavior. Perhaps his oncologist could encourage him to see a specialist in memory disorders? Perhaps you could get him to see a specialist for a symptom that IS bothering him or which seems less stigmatizing or more familiar to him.? Could you suggest he may be depressed again, and there are successful treatments for depression? The goal of adequate diagnosis and treatment justifies the means. Find a way to deliver a description of his symptoms to the specialist