Figure 3 and Table 1 show the comparison of pooled prevalence estimates between the adult vs. paediatric subgroups. Pooled prevalence for any psychiatric comorbidity was similar in adult studies and paediatric studies (71 and 64%, p = 0.51). Anxiety disorders were the most common comorbidity in the paediatric subgroup whereas mood disorders were the most common in the adult subgroup. Significant differences between the subgroups were found for MDD (41 vs. 17%, p < 0.001), and GAD (15 vs. 27%, p = 0.029), whereas NDDs, specifically tic disorders and ADHD showed similar pooled prevalence across adult and paediatric subgroups.
