As a topic for the exam, PTSD isn't all that complicated. The differential between acute stress and PTSD is one easy opening for test writers. Co-occurring PTSD and substance abuse is another. One way to approach the topic for the social work exam is to think what you would do if you had to come up with questions for the exam--about PTSD and whatever else. Where would you go to get ideas?
As you're preparing for the exam, everything you read and encounter that has to do with social work is potentially useful as exam prep. An article about soldiers struggling as they return to civilian life...there's a vignette question in there. Breakthroughs with new treatments (e.g., EMDR)...another potential question.
But first, here are some places to go--the usuals--to get down the basics about PTSD.
What is post-traumatic stress disorder? (NIMH)
Posttraumatic stress disorder (Wikipedia)
PTSD (NCBI)
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