Narcolepsy Support Group
A sleep disorder (somnipathy) is a disorder in the sleep patterns of a person or animal. Some sleep disorders can interfere with mental and emotional function. If you are having trouble falling asleep or having some other kind of sleep disturbance, this group is for you.
A. All medications being taken should first be discussed with a physician before making an appointment for a sleep study. Certain medications, such as sleeping pills, stimulants, anti-histamines and drugs for anxiety and depression can interfere with the test results, and may need to be discontinued prior to the evaluation. However, unless instructed otherwise by a physician, you should continue to take all your medications on the day and night of the sleep test.
Found at: http://www.goodnightsleepwell.com/Services.aspx
But I totally forgot, and stayed on all my meds (including my "anti-narcolepsy" medications) and walked into the study with a coffee in my hand. They were all ready to send me home, saying there was no way that I could take the tests. I assured them that it would all work just fine, and indeed it did.
So despite all the medications and stimulants, I was still diagnosed with Narcolepsy from that study.