I've read some articles lately about worry and how there are basically two types of worry:one doesn't last long and makes  you decide to do something ,solve a problem,act on itthe other one last longer [hours, days...] and makes you re-think same worrying thoughts  I'm interested in the second kind of worry and what's the purpose of prolonged worrying if there is any? Is there any reasons why some humans worry for a longer periods of time or is it a flaw of some kind? I.e. was it ever beneficial to human being to worry for so long? Also, why can such prolonged worry, even when one is not really aware of it, affect cognitive skills,like remembering something, making decisions, problem solving, etc. ? NOTE: please tag appropriately if needed, as a layperson I'm not sure how to tag this question.
What's the purpose of worry [if there is any] and how and why does it affect cognitive skills?
memory;problem solving