These links may be a good place to get started with the questions you have.
Answers to Your Questions About Panic Disorder
National Center for PTSD
Obsessive-compulsive disorder (OCD), Mayo Clinic
International OCD Foundation
Sidran Traumatic Stress Institute
Depression and How Therapy Can Help
Mental Help Net - Personality Disorders
Note: Not responsible for the content, claims or representations of the listed sites.