Effects of Duloxetine on Pathological Worry in Patients With Generalized Anxiety Disorder: A fMRI Study

(1) to compare the differences of neural activation of pathological worry between pre-treatment GAD patients and normal subjects; (2) to measure the differences of brain activation on worry in GAD patients before and after duloxetine treatment

The study will recruit 20 GAD patients and 20 healthy controls. Both patients and controls receive a medical and psychiatric screening procedure at visit 1 and are asked to complete three self-rating questionnaires and one health questionnaire at visit 1. All qualified participants will receive functional magnetic resonance imaging (fMRI) at baseline.

The patients will begin treatment with duloxetine 30 mg/day at visit 2 and will be titrated to 60 mg/day at visit 3 (2 week since drug dispensed). The dosage will be maintained on 60 mg/day for 6 more weeks. During the period, the patients will receive periodic evaluations at visit 2 (0 week drug dispensed), 3 (2 week since drug dispensed), 4 (4 weeks since drug dispensed), and 5 (8 weeks since drug dispensed). The patients will receive fMRI examination at baseline and at the end of the 8-week treatment.

• Worry
• Anxiety

Inclusion Criteria:

• DSM-IV criteria of generalized anxiety disorders with moderate degree
• Participants above 18 years old

Exclusion Criteria:

• Major depression
• Panic disorder
• Obsessive-compulsive disorder
• Post-traumatic disorder
• Eating disorders
• Psychotic disorders; and
• Alcohol or other substance use disorders
• Neurological disease
• Cardio-vascular disease
• Respiratory disease
• Head trauma