Obsessive-compulsive disorder and separation anxiety co-morbidity in earlyonset panic disorder

Background. This study was undertaken to examine the relationship between a nxiety co-morbidity and age of onset of panic disorder. Methods. Age of onset of panic disorder and co-morbid anxiety disorders wer e assessed among 201 panic disorder probands with childhood separation anxi ety disorder, obsessive-compulsive disorder, obsessive-compulsive symptoms, social phobia and specific phobia as part of a clinician-administered life time diagnostic interview. A generalized linear model was used to test the association between each anxiety co-morbidity and age of panic disorder ons et while simultaneously controlling for the potential confounding effects o f sociodemographic characteristics and other psychiatric co-morbidity. Results. Earlier onset of panic disorder was found in patients with co-morb id obsessive-compulsive disorder, obsessive-compulsive symptoms and separat ion anxiety disorder, but not simple phobia or social phobia. Patients with both childhood separation anxiety disorder and obsessive-compulsive disord er had an even earlier panic onset than those with either childhood separat ion anxiety disorder or obsessive-compulsive disorder. Conclusions. The association between anxiety co-morbidity and earlier onset of panic disorder is specific to obsessive-compulsive disorder and childho od separation anxiety disorder.