We identified a total of 36 788 cases (20 791 women; 56.52%) diagnosed with OCD in the NPR during the 44-year study period. Of those, 87.00% (n=32 005) were diagnosed with an ICD-10 code. As expected, individuals with OCD had higher rates of other lifetime psychiatric disorders, compared with the general population (Table 1). A total of 76.40% (n=26 634) of the OCD cases had at least one comorbid psychiatric disorder, as compared with 12.09% (n=44 486) of the control group (OR=22.15 (95% CI, 21.53–22.79)). Parents of individuals with OCD and parents of control cases had a similar level of education (Table 1).
