Why would an active 70-year-old man with a quiet personality, seemingly happy with a calm lifestyle, undergo a sudden and extreme personality change? We were married 33 years, but because of my health I finally had to leave him after three years of constant worry. His family is grossly neglected, and his interest in young females has become so extreme that he lives with them and caters to their every whim. His children are concerned about his lack of judgment, use of Viagra, wild driving and lifestyle. I have sought help from the medical community but get no answers.

Granny

I can't say what caused your husband's (or ex-husband's) changes without talking with him personally. But I'll mention some possibilities that come to mind, which you can explore or discard as you (or he) deem appropriate.

One factor to consider when an older person undergoes a sudden personality change is the possibility of some kind of mini-stroke or other neurological impairment that might have affected parts of the brain that govern impulsivity, judgment and various behaviors. A neurologist or neuropsychologist (neither of which I am) might be able to tell you more about this possibility. Other possible explanations (or contributing factors) for sudden personality and/or behavior changes at any age can be substance abuse (drugs or alcohol) or head injury, brain tumor, etc. Of course, only a thorough assessment by an appropriate professional could determine whether there is a physical or medical cause for extreme personality changes.

There may also be psychological reasons for such a personality or behavior change. You mention Viagra, "interest in young females," and "wild driving and lifestyle." Aside from the Viagra, that scenario sounds much like the popular stereotype of a male midlife crisis. Reasons for such acting-out can vary, but often relate to anxiety about aging or mortality (hence the pursuit of a "young" lifestyle, fast cars, etc. in what is sometimes an attempt to recapture the vitality -- and risk-taking -- of youth) and/or anxiety about appearance or sexual prowess (which may lead to sexual escapades as an attempt to reassure oneself of attractiveness and virility).

I've heard of some older men with longstanding erectile dysfunction becoming sexually voracious -- even promiscuous -- after discovering the chemical assistance of Viagra ... much to their wives' chagrin. But I don't think the medication alone can be blamed when any resurgent sexual interest (or ability) is taken outside of marriage; one would need to examine the marital dynamics as well.

That said, I'm sorry for the pain your husband's (or ex-husband's) behavior has caused you and your children. I hope your health has improved since you left him. You've probably already figured out by now that his behavior will not change unless he wants it to, or unless he at the very least agrees to undergo a thorough medical and possibly psychological evaluation. If you continue to puzzle over the situation, perhaps it would help to consult personally with a psychologist or other counselor.