I agree with the wise posters above.

In addition, I would like to point out that his failed relationships from the past may not fit the definition of PTSD.

Unless your boyfriend had "exposure to actual or threatened death, serious injury, or sexual violence" (DSM-5) in his previous romantic relationships, he cannot be diagnosed with PTSD from them.


I agree with your therapist.


No it is not his PTSD.

Yes PTSD can cause flashbacks of the traumatic events--the ones that caused the disorder--not flashbacks to just any negative event in the person's past.