[1] Dalhousie Univ, Dept Psychiat, QE II Hlth Sci Ctr, Halifax, NS B3H 2E2, Canada
[2] Ohio State Univ, Nisonger Ctr, Columbus, OH 43210 USA
[3] Univ Nijmegen, Med Ctr, Nijmegen, Netherlands
[4] Univ Ulm, Clin Child & Adolescent Psychiat & Psychotherapy, Ulm, Germany
[5] Case Western Reserve Univ, Univ Hosp Cleveland, Cleveland, OH 44106 USA
[6] Univ Western Ontario, Dept Psychiat, London, ON N6A 3K7, Canada
[7] Univ Hosp Berlin, Psychiat Clin, Berlin, Germany
[8] Columbia Univ, New York State Psychiat Inst, New York, NY USA
[9] Ross Ctr Study Anxiety & Related Disorders, Washington, DC USA
[10] Tel Aviv Univ, Dept Psychiat, Tel Aviv, Israel
[11] Maudsley Hosp & Inst Psychiat, Inst Psychiat, London, England
[12] Univ Utrecht Hosp, Dept Child & Adolescent Psychiat, Utrecht, Netherlands