Thyroid disease in cats is linked to heart disease and a fast heartbeat in conjunction with any other symptoms of thyroid problems is cause for a trip to the vet. Once the hyperthyroidism is treated, your cat's heart rate should return to normal.
Stress reaction â some studies have found that paranoia is more common in people who have experienced severe and ongoing stress â for example, prisoners of war. How stress can trigger paranoia is unclear.
Drug intoxication - various drugs are a common cause of both delusions and paranoia symptoms. Marijuana intoxication - can cause delusions and paranoia. Speed intoxication - also causes delusions/paranoia. Bipolar disorder - may have delusion symptoms in both the up and down phases.