Anxiety disorders are collectively known as ________________.

Fifty-year-old Heather's decreased estrogen production is an example of

A) the cross-linkage theory of aging. B) gradual failure of the endocrine system. C) a decline in immune system functioning. D) telomere shortening.

Although bipolar I disorder is described as "bipolar,"

a. a depressed episode is not necessary for a diagnosis. b. few patients show both manic and depressed symptoms. c. both depressed and manic symptoms typically occur simultaneously. d. a year or two commonly passes between manic and depressed episodes.