New York Subscriber
Answer: Your best option is to code according to your physician's note.
If he states in his impression that he believes the patient is faking the illness, report V65.2 (Person feigning illness). If you (and your physician) feel more comfortable with a more conservative route, report a generic headache code such as 784.0 (Headache), or 346.9x (Migraine, unspecified) if your neurologist actually diagnosed a migraine.
Document it: If your physician really believes the patient is seeking drugs, he should flag the patient's chart for future reference.