This screams cluster B/BPD to me, which obviously has a tremendous overlap with PTSD. Quite commonly, even by seasoned psychiatrists, these patients are diagnosed as "bipolar," for various reasons including poor historians, the akiskal-bipolar spectrum and temperament interpretations, minimal response to antidepressants. More commonly I've seen people this age that were diagnosed as "bipolar" in their wayward youth, which hopefully we all know doesn't map out to adult bipolar, but were treated with atypicals and mood stabalizers for their temper dysregulation. Thankfully the field is moving away from calling all of this bipolar, though they may all get
some benefit from mood stabalizing medications, and is conceptualizing everything on a spectrum, rather than categorical diagnosis. Quetiapine may not be the worst choice, though certainly isn't the first choice, in bipolar or PTSD.
http://www.ncbi.nlm.nih.gov/pubmed/21597381