Cost of anxiety disorders: impact of comorbidity.

The aim of this study was to assess the relative impact of co-mobidity and of symptom severity on the costs of caring for patients with generalized anxiety disorders (GAD). One thousand and forty-two patients with GAD according to DSM III-R were observed by psychiatrists using a cross-sectional methodology. Demographic, clinical, therapeutic as well as health care utilization data were collected at a single point in time. Patients were stratified according to prevalence of co-morbidity. An economic analysis was performed based on a societal perspective. Hospitalizations and losses of productivity were the two major components of costs both in patients with and without co-morbidity. On the other hand costs of pharmaceuticals remain a marginal component of costs associated with GAD in the two groups. Controlling for confounding variables, the prevalence of health care utilisation was found to be significantly higher in patients with co-morbidity for hospitalization, laboratory tests, medications and absenteeism from work. Most of cost components were found to be significantly higher in patients with co-morbidity. The relative risk of health care utilization was higher in patients with co-morbidity, past history of anxiety, high level of anxiety as well as in older patients. Overall our findings suggest that both co-morbidity and symptom severity play a role in cost generation in GAD patients.