One more common symptom of this mental disorder is paranoia. We often call people ‘paranoiacs’ jokingly when they are too anxious about some things that are not worth that attention. In fact, a paranoid type of the mental disorder is not about some fun: it may be rather serious. In most cases, the person cannot manage the paranoia: even if he or she realizes everything is fine, the individual remains rather scared and anxious. It may be caused by the feeling of discomfort or false thoughts.