Yeh I think so too, but we'll give him/her the benefit of the doubt.
If you take that much diphenhydramine, you are risking rebound allergies to say the least! Histamine has a strong stimulating effect on the brain, it that, like dopamine, an "aerosol" of histamine is sprayed over diffuse areas of the brain, which regulates waking states (circadian). Fucking with this system is going to be just as bad as what happens when the dopamine system burns out due to, for example meth. People coming off meth have screwed the dopamine "aerosol", and the symptoms ain't pretty. You're risking the same thing, but without any real high!