Yes! Lamictal will show a false positive on drug screens. You can have a lab use a maspectrometer specifically for PCP in order to officially rule it as a "false positive."
Yes, It happened to me, and now it's in my medical records that I take PCP, marijuana, benzodiazepines, opiates, amphetamines and cocaine, all from simply taking a doctor-prescribed prescription of Seroquel. The stuff is nasty and does all sorts of things to your system and your mind. It's an anti-psychotic, and I was given it to help me sleep. Doctors really need to be more careful about which drugs they prescribe for which conditions. In my opinion, Seroquel should be taken off the market. Those tests will remain in my records for the rest of my life, and I do NOT take any street drugs. I've been denied narcotics after surgery due to the Seroquel causing so many false-positive test results for street drugs. I've done all the research and even shown my doctor all the official sites that list what false positives you can get while taking Seroquel, and he refuses to believe me. Definitely time to get a new doctor. I am livid.