David has gone to his physician complaining of 10 to 15-minute episodes that occur out of the blue. He has a very rapid heart rate (he can feel it thumping in his chest) accompanied by heavy breathing. Upon questioning, he reveals that during the episodes he is certain death is imminent and is scared out of his wits. After many tests, his doctor finds David in excellent physical health. To what psychological condition might his symptoms most likely be attributed?
1) Schizophrenia
2) Cognitive disorder
3) Panic disorder
4) Obsessive-compulsive attacks