Years after he barely survived a terrorist attack that killed his wife and two children, mr. puskari suffers recurring flashbacks and frequent nightmares of the event that render him incapable of holding a steady job. mr. puskari is most clearly showing signs of:

post-traumatic stress disorder.          

Explanation:

Post-traumatic stress disorder: In psychology, the term post-traumatic stress disorder is also referred to as PTSD and is described as a mental illness, or mental disorder that triggers an individual by terrifying events by the direct or indirect exposure to it i.e, either by experiencing or witnessing.

Symptoms: Nightmares, uncontrollable thoughts, severe anxiety, etc.

An individual can experience PTSD at any age of his or her life.

Events that can be responsible for PTSD are sexual or physical assault, serious accidents, childhood or domestic abuse, etc.

In the question above, Mr. Puskari is most clearly showing signs of PTSD.