Some researchers think that anxiety and anger are linked and that a genetic predisposition to over-react to things, or to see them as a threat, leads some people to worry and fret, developing an anxiety disorder, while others become angry and lash out. Other people think that the anger felt by people with an anxiety disorder is due to the depression that they often also feel and not their anxiety. Researchers from Florida State University used information from 5,692 people who took part in the National Comorbidity Survey. They found that there was a link between anxiety and anger, independent of depression, but that post-traumatic stress disorder (PTSD) and panic disorder were 'not consistently associated with anger experience and expression.'
Hawkins, Kirsten A. and Cougle, Jesse R. - Anger problems across the anxiety disorders: findings from a population-based study Depression and Anxiety doi: 10.1002/da.20764