Symptom dimensions in OCD: item-level factor analysis and heritability estimates.
To reduce the phenotypic heterogeneity of obsessive-compulsive disorder (OCD) for genetic, clinical and translational studies, numerous factor analyses of the Yale-Brown Obsessive Compulsive Scale checklist (YBOCS-CL) have been conducted. Results of these analyses have been inconsistent, likely as a consequence of small sample sizes and variable methodologies. Furthermore, data concerning the heritability of the factors are limited. Item and category-level factor analyses of YBOCS-CL items from 1224 OCD subjects were followed by heritability analyses in 52 OCD-affected multigenerational families. Item-level analyses indicated that a five factor model: (1) taboo, (2) contamination/cleaning, (3) doubts, (4) superstitions/rituals, and (5) symmetry/hoarding provided the best fit, followed by a one-factor solution. All 5 factors as well as the one-factor solution were found to be heritable. Bivariate analyses indicated that the taboo and doubts factor, and the contamination and symmetry/hoarding factor share genetic influences. Contamination and symmetry/hoarding show shared genetic variance with symptom severity. Nearly all factors showed shared environmental variance with each other and with symptom severity. These results support the utility of both OCD diagnosis and symptom dimensions in genetic research and clinical contexts. Both shared and unique genetic influences underlie susceptibility to OCD and its symptom dimensions.
Katerberg
Hilga
H
Department of Psychiatry, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Delucchi
Kevin L
KL
Stewart
S Evelyn
SE
Lochner
Christine
C
Denys
Damiaan A J P
DA
Stack
Denise E
DE
Andresen
J Michael
JM
Grant
J E
JE
Kim
Suck W
SW
Williams
Kyle A
KA
den Boer
Johan A
JA
van Balkom
Anton J L M
AJ
Smit
Johannes H
JH
van Oppen
Patricia
P
Polman
Annemiek
A
Jenike
Michael A
MA
Stein
Dan J
DJ
Mathews
Carol A
CA
Cath
Danielle C
DC
D000465:Algorithms; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D005163:Factor Analysis, Statistical; D005190:Family / Q000523:psychology; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008960:Models, Psychological; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000235:genetics* / Q000523:psychology; D010641:Phenotype; D025341:Principal Component Analysis; D011594:Psychometrics