Mahjani et al. [11] also analyzed the OCD familial risk in the Swedish population. The cohort enrolled 822,843 people born between 1982 and 1990, of which 7184 (0.87%) were diagnosed with OCD. The relative recurrence risks (RRRs) confirmed the OCD familial pattern (RRR = 4.82, 95% CI = 4.03–5.62 for full siblings; RRR = 1.85, 95% CI = 0–3.27 for maternal half-sibling; RRR = 1.09, 95% CI = 0–1.96 for paternal half-siblings; RRR = 1.85, 95% CI = 1.29–2.41 for maternal cousins; and RRR = 1.59, 95% CI = 1.13–2.08 for other cousins).
