A 44 year old man presents with fears that his mathematical abilities have been slowly sucked out of his brain for the last four years. He believes an "alien force disguised as a human being" is responsible. To avoid contact with this being, he has isolated himself in a room in a boarding house. He has left his wife and children. After ten years teaching math at a local high, he resigned about 3 years ago. He suppos himself by 'collecting cans." His effect is blunted. His appearance is disheveled,unshaven and unwashed.Which of the following is least suggestive of a schizophrenic disorder in this man?