People who experience chronic stress exhibit a decrease in which of the following physiological responses?

Excerpt from "The Chicago Employment Agency and the Immigrant Worker," Grace Abbott, American Journal of Sociology 1908 14:3, 289-305

In the late nineteenth and early twentieth centuries, immigrants poured into the United States without knowledge of English or American customs. They were also usually unaware of the local cost of living or typical wage. These immigrants turned to employment agencies that would help them find work, for a fee. The extreme dependence of immigrants on the employment agencies coupled with their general ignorance of the American system brought about an ethical dilemma for the employment agent in which it became very easy to take advantage of people seeking a job. This resulted in an extreme prejudice directed at immigrants by the American employment system. A study was conducted in the early 1900s gauged the degree of corruption among employment agents and the results of this study have been provided (see Tables 1, 2, and 3)

Table 1

Table 2

Table 3

Unemployment and underemployment can be major causes for stress. Which of the following physiological responses would be expected for someone in a stressful situation?

I. Increase in cortisol levels

II. Decrease in cortisol levels

III. Increase in thyroid stimulating hormone (TSH)

IV. Decrease in TSH

Which chemical is responsible for the initiation of the stress response?