Figure 2.1.1–2.36.2 in Supplementary File 3 shows the results of the main meta-analysis for each disorder. Tables 1, 2, and Figure 2 show results of the main meta-analysis for each disorder, along with the number of studies and the total number of OCD subjects represented within the studies. In entirety, 69% (95% CI 59–78%) of the pooled sample had any psychiatric comorbidity. The most common comorbidity type, according to the highest pooled prevalence, was mood disorders, with a prevalence of 48% (95% CI 39–57%). The second most common comorbidity type was anxiety disorders, with a pooled prevalence of 32% (95% CI 24–40%). Other prominent comorbidities included ADHD [16% (95% CI 13–19%)], tic disorders [14% (95% CI 11–17%)], and OCRDs [14% (95% CI 4–28%)]. Autism spectrum disorders (ASD) [6% (95% CI 4–8%)] and oppositional defiant disorder (ODD) [12% (95% CI 2–29%)] were primarily reported in paediatric studies (only 1 study on adults reported ASD, while none reported ODD). The prevalence of personality disorders, from studies on adults, was also found to be high [35% (95% CI 28–42%)]. Among personality disorders, the
