Tom's case, as described in your textbook, illustrates which of the following characteristics of personality disorders that would allow a clinician to differentiate his disorder from other disorders that are more episodic in nature?

a. Tom's problems were intense but very brief.
b. Tom understood the nature for his problems and felt bad about them.
c. Tom's problems began early and were exhibited consistently over an extended period of time.
d. Tom was able to recognize his need for help and participate actively in treatment.

Answer: c.