A merry heart like a medicine?

A merry heart doeth good like a medicine: but a broken spirit drieth the bones. (Proverbs 17:22)

Do we need a scientific study to verify whether this ancient wisdom really holds water? Wash your hands regularly, use plastic gloves, practice social distancing, wear masks are really important to do. But being worn out, depressed, full of fear, that is ok?

Why are the elderly much more susceptible to coronavirus? Would it not be more accurate to say that those who are carrying around old resentments, old regrets, old complaints, etc. are more susceptible. There are plenty of examples of the very elderly who are full of vim and vigor, who are clearly not bowed down with the old weights, and I suspect are not more susceptible to coronavirus.

In my own experience, I observed a perennially cheerful woman, and very healthy, in her latter years became obsessed with a resentment towards her daughter-in-law. It had been in the background for years, but now it took center stage despite her having very little contact. No amount of reasoning and encouragement affected her. She exemplified “a broken spirit drieth the bones.” Failing health followed quickly.

Now a merry heart has little to do with partying and having a good time for often (not always!) those offer an escape from facing what needs attention in the heart. The present period of self-quarantining, social distancing, etc. provides a great opportunity for self-examination, to look honestly and deeply to the heart and insure there is nothing festering, no negative sentiment, nothing interfering with a merry heart.

The following excerpt is an urgent call in this direction (Note that the reference to Christian Science has nothing to do with religion or denomination, but the example and teaching of Jesus Christ.):
Man's enslavement to the most relentless masters — 
passion, selfishness, envy, hatred, and revenge — is conquered only by a mighty struggle. Every 
hour of delay makes the struggle more severe. 
If man is not victorious over the passions, they crush 
out happiness, health, and manhood. Here Christian 
Science is the sovereign panacea, giving strength to the 
weakness of mortal mind, — strength from the immortal 
and omnipotent Mind, — and lifting humanity above 
itself into purer desires, even into spiritual power and 
good-will to man. (Science and Health with Key the Scriptures, by Mary Baker Eddy)