I'm not a doctor and I really don't know that much about this...

But I did think of this... a lot of the anti-psychotic type drugs hit the histamine receptors in the brain. This is why Seroquel makes my nose stuff up and gives me marijuana-like munchies. Histamine receptors. (histamine, as in anti-histamine, as in allergy control)

This is a long shot and I'm no pharmacologist or anything...

But might there be a connection between the action of the allergy shot and histamine receptors and the meds??? (possibly blocking the action of the meds, or down or up-regulating the receptors so they aren't as sensitive to the meds or something like that...)

Bring it up with your doc... hopefully he'll listen even though he'll probably think you have no idea what you are talking about...

http://en.wikipedia.org/wiki/Histamine_receptor

http://en.wikipedia.org/wiki/Antihistamine

...Other agents with antihistaminergic activity
Many drugs, used for other indications, possess unwanted antihistaminergic activity. These include tricyclic antidepressants, antipsychotics, etc.