All of the following fall into the category of anxiety disorders EXCEPT

a) Posttraumatic stress disorder
b) Hypochondriasis
c) Obessive-compulsive disorder
d) Specific phobie
e) Panic Disoder

I believe the answer is B

I would disagree with that... check this definition.

sometimes referred to as health phobia) refers to an excessive preoccupation or worry about having a serious illness.

I searched Google under the key words "anxiety disorder" to get these possible sources:

http://en.wikipedia.org/wiki/Anxiety_disorder
http://www.nimh.nih.gov/health/topics/anxiety-disorders/index.shtml
http://www.nimh.nih.gov/health/publications/anxiety-disorders/complete-publication.shtml

Which alternative is not listed?

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.

I hope this helps a little more. Thanks for asking.

To determine the correct answer, we need to understand what each of the options refers to and then eliminate the option that does not fit into the category of anxiety disorders.

a) Posttraumatic stress disorder (PTSD) is an anxiety disorder that can occur after experiencing or witnessing a traumatic event.

b) Hypochondriasis, also known as illness anxiety disorder, is characterized by excessive worry about having a serious medical condition despite minimal or no evidence of an actual illness. It is indeed considered an anxiety disorder.

c) Obsessive-compulsive disorder (OCD) is an anxiety disorder that involves recurrent obsessions (intrusive thoughts, images, or urges) and compulsions (repetitive behaviors or mental acts performed to reduce distress or prevent a feared event). It is another example of an anxiety disorder.

d) Specific phobia refers to an intense, irrational, and persistent fear of a specific object or situation. It is categorized as an anxiety disorder.

e) Panic disorder involves recurrent, unexpected panic attacks (sudden episodes of intense fear or discomfort) accompanied by physical symptoms such as rapid heartbeat, chest pain, shortness of breath, and dizziness. It is a recognized anxiety disorder.

Given this information, we can conclude that the exception (option that does not belong to the category of anxiety disorders) is therefore option B, Hypochondriasis.