Sentence:  Failure confirms the threat , and the intensity of <WSD>anxiety</WSD> is increased as the required learning becomes more difficult , so that by the time the child reaches the third grade the decrement in performance is pronounced . 
Meaning of the word marked with <WSD> tags:  (psychiatry) a relatively permanent state of worry and nervousness occurring in a variety of mental disorders, usually accompanied by compulsive behavior or attacks of panic