Table II. Family studies of OCD. The rates shown refer to the frequency of these conditions among first-degree relatives.

Adapted from ref 5: Pauls DL. The genetics of obsessive compulsive disorder: a review of the evidence. Am J Med Genetics C: Sem Med Genet. 2008;148:133-139. Copyright © Wiley-Liss 2008

Family history studies	Obsessive-compulsive illness	Obsessive-compulsive features		Controls
Luxenburger44	0.08	0.08		---
Lewis45	---	0.327		---
Brown46	0.073	---		---
Rüdin47	0.040	0.070		---
Kringlen48	0.198			---
Rosenburg49	0.004	---		---
Insel et al50	0	0.150		---
Rasmussen & Tsuang51	0.045	0.114		---
Adult family studies	OCD	Subclinical OCD	OCD		Subclinical OCD
Mckeon & Murray52	0.007	---	0.007
Bellodi et al53	0.034	---	---		---
Black et al54	0.025	0.156	0.023		0.029
Nicolini et al55	0.049	---	---		---
Pauls et al38	0.103	0.079	0.019		0.020
Nestadt et al56	0.117	0.046	0.027		0.030
Albert et al57	0.035	---	---		---
Fyer et al58	0.062	0.084	0		0
Lipsitz et al59*	0.026	0.057	0.013		0.013
Grabe et al60**	0.064	0.055	0.012		0.030
Child family studies	OCD	Subclinical OCD	OCD		Subclinical OCD
Lenane et al61	0.170	---	---		---
Riddle et al62	0.095	---	---		---
Leonard et al63	0.130	---	---		---
Reddy et al64	0.050	---	0		---
Chabane et al65	0.170	---	---		---
Hanna et al40	0.225	---	0.026		---
Rosario-Campos et al41	0.227	0.065	0.009		0.015