The following instruments will be completed at the screening visit and periodically throughout the study: 1) Yale-Brown Obsessive Compulsive Scale Modified for Pathological Gambling (PG-YBOCS), a reliable and valid semi-structured clinician-administered scale that assesses current severity of PG; 2) Gambling Symptom Assessment Scale (G-SAS), a reliable and valid self-report measure of gambling symptoms; 3) the 17-item Hamilton Rating Scale for Depression (HAM-D); 4) the 17-item Hamilton Rating Scale for Anxiety (HAM-A); 5) Clinical Global Impression scale; 6) the Sheehan Disability Inventory; and 7) the Quality of Life Inventory. Safety evaluations, including pulse and blood pressure, and assessment of side effects will be done at each visit.