Comorbidity Patterns of Anxiety and Depressive Disorders in a Large Cohort Study

Comorbidity of depressive and anxiety disorders is common and has been shown to be a consistent predictor of chronicity. Comorbidity patterns among specific depressive and anxiety disorders have not been extensively reported. This study examines comorbidity patterns and temporal sequencing of separate depressive and anxiety disorders using data from a large psychiatric cohort. METHOD: Baseline data (N = 1,783) of the Netherlands Study of Depression and Anxiety, collected between September 2004 and February 2007, were used. Current and lifetime comorbidity rates for depressive and anxiety disorders (DSM-IV-TR criteria) were calculated. Associations of comorbidity with sociodemographic, vulnerability, and clinical characteristics, and temporal sequencing of disorders were examined.

Of those with a depressive disorder, 67% had a current and 75% had a lifetime comorbid anxiety disorder. Of persons with a current anxiety disorder, 63% had a current and 81% had a lifetime depressive disorder. Comorbidity of depressive and anxiety disorders was associated with more childhood trauma (OR = 1.19; 95% CI, 1.06-1.33), higher neuroticism (OR = 1.05; 95% CI, 1.02-1.08), earlier age at onset of first disorder (OR = 1.59; 95% CI, 1.22-2.07), longer duration of depressive and/or anxiety symptoms (OR = 1.01; 95% CI, 1.01-1.01), and higher symptom severity (ORs ranging from 1.01 to 1.03; all P values