Twin studies of anxiety disorders indicate that generalized anxiety disorder has a heritability of
a. around 20 to 30 percent.
b. less than 5 percent.
c. over 50 percent.
d. almost 100 percent.
Question 2
The episodic nature of obsessive-compulsive disorder symptoms is thought to be related to
a. cycles of activity in neurotransmitters.
b. changing levels of environmental stress.
c. changes in the ability to suppress thoughts.
d. a rebound from attempts to suppress strong emotion.