Abstract : Comorbidity in Generalized Anxiety Disorder: Prevalence and Course After Cognitive-Behavioural Therapy

Objective: To evaluate the prevalence and course of Axis I concurrent disorders in a population of patients who underwent cognitive-behavioural therapy (CBT) to treat their generalized anxiety disorder (GAD).

Method: This study is a secondary analysis combining patients from 3 treatment studies done at Université Laval. A total of 90 patients with a DSM-IV consistent GAD diagnosis received from 12 to 16 CBT sessions to treat GAD. Symptomatology was assessed at pretest, posttest, and 6 months after treatment, with the Anxiety Disorders Interview Schedule, a structured diagnostic interview.

Results: Seventy-three per cent of patients had both GAD and a concurrent diagnosis. The most common diagnoses were simple phobia, social phobia, panic disorder, and major depression. CBT applied to GAD decreases the number of concurrent diagnoses. A panic disorder or a greater number of concurrent diagnoses at pretest is associated with a less efficient treatment at follow-up 6 months later.

Conclusion: Patients with GAD have a high comorbidity rate with other Axis I disorders, but these significantly decrease after a short CBT aimed at GAD. Implications for GAD treatment and mechanisms that might explain these findings are discussed.