About Panic Disorder Panic disorder is an anxiety disorder characterized by recurrent unexpected panic attacks followed by at least one month of persistent concern about having another attack. Many people with panic disorder develop intense anxiety between episodes, in anticipation of the next attack, and they may develop phobias about places or situations where panic attacks have occurred. This may eventually develop into agoraphobia, an inability to go beyond known and safe surroundings because of intense fear and anxiety. Common situations avoided by many people with panic disorder include driving over bridges or through tunnels, riding in elevators or airplanes, visiting a dentist, and shopping at an indoor mall.