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 (PTSD) is very commonly found in people who have experienced a severely traumatic event. This is commonly seen in war veterans as a result of traumatic events. Examples include seeing a family member die, or being a part of a terrible accident.

The brain often cannot recognize it as something that actually happened, so it stops the sufferer from functioning as a normal person in society, and sufferers often have to have special care.