Obsessive-compulsive disorder: subclassification based on co-morbidity.
BACKGROUND
Obsessive-compulsive disorder (OCD) is probably an etiologically heterogeneous condition. Many patients manifest other psychiatric syndromes. This study investigated the relationship between OCD and co-morbid conditions to identify subtypes.


METHODS
Seven hundred and six individuals with OCD were assessed in the OCD Collaborative Genetics Study (OCGS). Multi-level latent class analysis was conducted based on the presence of eight co-morbid psychiatric conditions [generalized anxiety disorder (GAD), major depression, panic disorder (PD), separation anxiety disorder (SAD), tics, mania, somatization disorders (Som) and grooming disorders (GrD)]. The relationship of the derived classes to specific clinical characteristics was investigated.


RESULTS
Two and three classes of OCD syndromes emerge from the analyses. The two-class solution describes lesser and greater co-morbidity classes and the more descriptive three-class solution is characterized by: (1) an OCD simplex class, in which major depressive disorder (MDD) is the most frequent additional disorder; (2) an OCD co-morbid tic-related class, in which tics are prominent and affective syndromes are considerably rarer; and (3) an OCD co-morbid affective-related class in which PD and affective syndromes are highly represented. The OCD co-morbid tic-related class is predominantly male and characterized by high conscientiousness. The OCD co-morbid affective-related class is predominantly female, has a young age at onset, obsessive-compulsive personality disorder (OCPD) features, high scores on the 'taboo' factor of OCD symptoms, and low conscientiousness.


CONCLUSIONS
OCD can be classified into three classes based on co-morbidity. Membership within a class is differentially associated with other clinical characteristics. These classes, if replicated, should have important implications for research and clinical endeavors.
Nestadt
G
G
Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA. gnestadt@jhmi.edu
Di
C Z
CZ
Riddle
M A
MA
Grados
M A
MA
Greenberg
B D
BD
Fyer
A J
AJ
McCracken
J T
JT
Rauch
S L
SL
Murphy
D L
DL
Rasmussen
S A
SA
Cullen
B
B
Pinto
A
A
Knowles
J A
JA
Piacentini
J
J
Pauls
D L
DL
Bienvenu
O J
OJ
Wang
Y
Y
Liang
K Y
KY
Samuels
J F
JF
Roche
K Bandeen
KB
D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003865:Major Depressive Disorder / Q000145:classification / Q000175:diagnosis / Q000235:genetics / Q000523:psychology; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000145:classification* / Q000175:diagnosis / Q000235:genetics / Q000523:psychology; D009771:Obsessive-Compulsive Disorder / Q000145:classification* / Q000175:diagnosis / Q000235:genetics / Q000523:psychology; D010552:Personality Assessment / Q000706:statistics & numerical data; D010554:Personality Disorders / Q000145:classification / Q000175:diagnosis / Q000235:genetics / Q000523:psychology; D011594:Psychometrics; D012737:Sex Factors; D013981:Tic Disorders / Q000145:classification / Q000175:diagnosis / Q000235:genetics / Q000523:psychology