[1] First Pavlov State Med Univ, Valdman Inst Pharmacol, St Petersburg, Russia
[2] Bekhterev Natl Med Res Ctr Psychiat & Neurol, Dept Addict, St Petersburg, Russia
[3] First Pavlov State Med Univ St Petersburg, Lab Clin Psychopharmacol Addict, St Petersburg, Russia
[4] First Pavlov State Med Univ St Petersburg, Pharmacoepidemiol & Biostat, St Petersburg, Russia
[5] First Pavlov State Med Univ St Petersburg, Valdman Inst Pharmacol, St Petersburg, Russia
[6] Univ Penn, Dept Psychiat, Philadelphia, PA 19104 USA