One way Macbeth appears to be affected by paranoia is when he is at a dinner and imagines a floating dagger. He questions how real the dagger is and says, “Is this a dagger which I see before me” (Shakespeare 2:1:34). He knows the dagger is not real but he is still confused. It is simply a hallucination but it makes him feel guilt, temptation, and paranoia.
The second occurrence of Macbeth’s paranoia is right after he had the king murdered and becomes suspicious of Banquo. Macbeth shows fear of Banquo and his sons when he says,