Final answer:
The symptoms of nightmares, flashbacks, and poor concentration described by the 22-year old patient are indicative of post-traumatic stress disorder (PTSD), an anxiety disorder that occurs after severe psychological trauma.
Step-by-step explanation:
The 22-year old patient's complaints of nightmares, flashbacks, and poor concentration are most consistent with post-traumatic stress disorder (PTSD). PTSD is an anxiety disorder that can develop after an individual experiences severe psychological trauma.
These symptoms are not typically seen in other anxiety disorders to the extent that they are presented in PTSD. For instance, a panic attack is characterized by sudden periods of intense fear that may include palpitations, sweating, and feelings of doom. A phobic reaction is an excessive and persistent fear of a specific object, situation, or activity. Obsessive-compulsive disorder (OCD), on the other hand, involves unwanted and intrusive thoughts (obsessions) and repetitive behaviors (compulsions).
It's important to note that not all reactions to severe psychological trauma are classified as disorders; some argue that these reactions are normal. Nevertheless, PTSD was notably common among veterans following the Vietnam War, and it is shown to have long-lasting effects without proper treatment.