[1] Univ Calif San Francisco, Dept Psychiat, San Francisco, CA 94143 USA
[2] Univ Groningen, Univ Med Ctr Groningen, Dept Psychiat, Groningen, Netherlands
[3] Massachusetts Gen Hosp, Obsess Compuls Disorder Clin Adult & Pediat, Boston, MA 02114 USA
[4] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Psychiat & Neurodev Genet Unit, Boston, MA USA
[5] McLean Hosp, Obsess Compuls Disorder Inst, Belmont, MA 02178 USA
[6] Univ Amsterdam, Acad Med Ctr, Dept Psychiat, NL-1105 AZ Amsterdam, Netherlands
[7] Netherlands Inst Neurosci, Amsterdam, Netherlands
[8] Univ Stellenbosch, Dept Psychiat, MRC Unit Anxiety & Stress Disorders, ZA-7600 Stellenbosch, South Africa
[9] Vrije Univ Amsterdam, Med Ctr, Dept Psychiat, GGZ Buitenamstel, Amsterdam, Netherlands
[10] Univ Cape Town, Dept Psychiat, ZA-7700 Rondebosch, South Africa
[11] Univ Utrecht, Dept Clin & Hlth Psychol, Utrecht, Netherlands
[12] Altrecht Anxiety Outpatient Program, Utrecht, Netherlands