Further development of YBOCS dimensions in the OCD Collaborative Genetics study: symptoms vs. categories.
Despite progress in identifying homogeneous subphenotypes of obsessive-compulsive disorder (OCD) through factor analysis of the Yale Brown Obsessive-Compulsive Scale Symptom Checklist (YBOCS-SC), prior solutions have been limited by a reliance on presupposed symptom categories rather than discrete symptoms. Furthermore, there have been few attempts to evaluate the familiality of OCD symptom dimensions. The purpose of this study was to extend prior work by this collaborative group in category-based dimensions by conducting the first-ever exploratory dichotomous factor analysis using individual OCD symptoms, comparing these results to a refined category-level solution, and testing the familiality of derived factors. Participants were 485 adults in the six-site OCD Collaborative Genetics Study, diagnosed with lifetime OCD using semi-structured interviews. YBOCS-SC data were factor analyzed at both the individual item and symptom category levels. Factor score intraclass correlations were calculated using a subsample of 145 independent affected sib pairs. The item- and category-level factor analyses yielded nearly identical 5-factor solutions. While significant sib-sib associations were found for four of the five factors, Hoarding and Taboo Thoughts were the most robustly familial (r ICC>or=0.2). This report presents considerable converging evidence for a five-factor structural model of OCD symptoms, including separate factor analyses employing individual symptoms and symptom categories, as well as sibling concordance. The results support investigation of this multidimensional model in OCD genetic linkage studies.
Department of Psychiatry and Human Behavior, Brown Medical School, Butler Hospital, Providence, RI 02906, USA. Anthony_Pinto@brown.edu
Anthony
A
Pinto
Benjamin D
BD
Greenberg
Marco A
MA
Grados
O Joseph
OJ
Bienvenu
Jack F
JF
Samuels
Dennis L
DL
Murphy
Gregor
G
Hasler
Robert L
RL
Stout
Scott L
SL
Rauch
Yin Y
YY
Shugart
David L
DL
Pauls
James A
JA
Knowles
Abby J
AJ
Fyer
James T
JT
McCracken
John
J
Piacentini
Ying
Y
Wang
Virginia L
VL
Willour
Bernadette
B
Cullen
Kung-Yee
KY
Liang
Rudolf
R
Hoehn-Saric
Mark A
MA
Riddle
Steven A
SA
Rasmussen
Gerald
G
Nestadt
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005163:Factor Analysis, Statistical; D005190:Family / Q000523:psychology; D005260:Female; D008040:Genetic Linkage; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000235:genetics* / Q000523:psychology; D010555:Personality Inventory / Q000706:statistics & numerical data; D010641:Phenotype; D025341:Principal Component Analysis; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data*; D011594:Psychometrics