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This question originally appeared on Quora. Answer by David Chan, retired intensive care physician.

I give no credence to the concept of "will to live" when it comes to the large majority of medical problems unless a patient simply refuses treatment.

I’ve had patients who could barely accept treatment, felt tremendously depressed, dispirited, and pessimistic who overcame low odds to be cured. I’ve had other patients with tremendous attitude, fought the fight, always up, rallying staff, friends and family, an incredble pleasure to care for, who succumbed to cancers with good odds of a cure. Certainly a good attitude makes life and medical treatment more tolerable, but it doesn’t seem to effect outcome.

There is no data that postive attitude or having a great will to live helps someone survive serious illness. That’s a burden for cancer patients; to think that they are contributing to their ill health because their attitude is bad or they just need to try harder. It’s objectionable for others to place this added burden on ill patients.

If the patient is not attempting treatment or keeping treatment appointments because of poor attitude, that’s obviously a different issue altogether.

In "The Human Side of Cancer," Jimmie C. Holland, M.D., of Memorial Sloan-Kettering Cancer Center, devotes a whole chapter to this topic, and it is well worth a read.

The chapter starts like this:

“I got really depressed when people said I should think positive. I thought, “If that’s what I have to do to survive, I’m never going to make it.”

-John, a 52-year-old man with melanoma

“People keep telling me to be upbeat. I say, ‘Screw you. I’ll be however I please in dealing with this cancer. I’ve never been upbeat in my life.'”

-Michael, a 45-year-old schoolteacher with recently diagnosed sarcoma

Dr. Holland does a far better job than I could do in giving examples and why this particular tyranny is not a good thing for many sick people.

To summarize her, many pessimists survive, and many optimists die early from their diseases. Being one or the other is no guarantee any way.

How positive thinking affects patients with serious illnesses

Attitude Doesn't Affect Cancer Survival

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