A family genetic study of clinical subtypes of obsessive-compulsive disorder.
OBJECTIVE
The results of various family studies of obsessive-compulsive disorder have varied widely, possibly because of heterogeneity in the obsessive-compulsive disorder phenotype. The current study was conducted to determine familiality of checker and washer subtypes of obsessive-compulsive disorder compared with normal controls.


METHODS
In this study, all available first-degree relatives of 25 checker, 34 washer and 40 psychiatrically normal control probands were interviewed directly, using structured interviews.


RESULTS
The morbid risk of syndromal and subsyndromal obsessive-compulsive disorder was significantly greater among the relatives of checker probands (19.4%) than in the relatives of washer (8.7%) or control probands (5.4%), while the morbid risk for the relatives of washer and control probands was not significantly different. In all, 67% of the checker relatives with syndromal and subsyndromal obsessive-compulsive disorder were checkers, while 54% of the washer relatives with syndromal and subsyndromal obsessive-compulsive disorder were washers.


CONCLUSIONS
Our study provides preliminary evidence of familiality of the checker subtype of obsessive-compulsive disorder. Future studies using patients subtyped on the basis of symptom dimensions, in larger obsessive-compulsive disorder samples, are needed, to further validate the genetic basis of obsessive-compulsive disorder.
Bhattacharyya
Sagnik
S
Institute of Psychiatry, London, UK. S.Bhattacharyya@iop.kcl.ac.uk
Prasanna
Channarayapatna Lakshmi Narasimha
CL
Khanna
Sumant
S
Janardhan Reddy
Yemiganur Chendrashekhar
YC
Sheshadri
Shekhar
S
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000145:classification / Q000235:genetics*