In an exploratory post-hoc analysis, we examined if individuals with both OCD and TD/CTD (OCD + TD/CTD; n= 1,276) had similar comorbidity and familial risks of AD. The results revealed that these individuals had similar comorbidity (OR=1.48) to that reported in the main analyses above. The familial estimates were similar to those of TD/CTD probands, with one exception: the risk of AD in siblings was somewhat higher amongst OCD + TD/CTD probands (OR=1.38). However, these results need to be interpreted cautiously given the small sample size and wide confidence intervals (only 99 siblings of OCD + TD/CTD probands had at least one AD; Supplementary Table 4).
