Why Pessimism Shuts Down Our Immune System

PESSIMISM PRODUCES DEPRESSION. And when a person is depressed, certain brain hormones become depleted, creating a chain of biochemical events that end up slowing down the activity of the immune system. For example, two key players in our immune systems are T cells and NK cells.

T CELLS recognize invaders (like viruses) and make more copies of themselves to kill off the invaders. Pessimists' T cells don't multiply as quickly as optimists', allowing invaders to get the upper hand.

NK CELLS circulate in the blood and kill whatever they come across that they identify as foreign (like cancer cells). Pessimists' NK cells can identify foreign entities, but they don't destroy them as well as the optimists' NK cells.

Learn more about how to reduce your pessimism

Here's a conversational chapter on optimism from a future book:
Conversation on Optimism

If worry is a problem for you, or even if you would like to simply worry less even though you don't worry that much, you might like to read this:
The Ocelot Blues

Learn how to prevent yourself from falling into the common traps we are all prone to because of the structure of the human brain:
Thoughtical Illusions


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APA Reference
Staff, H. (2008, October 11). Why Pessimism Shuts Down Our Immune System, HealthyPlace. Retrieved on 2020, November 27 from

Last Updated: March 31, 2016

Medically reviewed by Harry Croft, MD

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