The sample consisted of 186 women (57%) and 139 men (43%), with a mean age at OCD onset of 14 years (SD, 9.6 years), which was similar to that in the SLC1A1 OCD study by Arnold et al (14.4 years)16 and higher than those in the studies by Dickel et al (8 years)17 and Stewart et al (7.9 years).18 As reported previously in our sample,29 mood (81%) and anxiety (53%) disorders were most frequently represented among comorbid disorders, with alcohol abuse disorder (24%), substance abuse disorders (14%), and tics (6%) less common. Hoarding, as we will define, was present in 27% of this patient sample. Total mean Yale-Brown Obsessive Compulsive Severity Scale (Y-BOCS) lifetime severity scale score was 29.6 (SD, 15.4), which is approximately equally contributed to by obsession and compulsion scores.
