The morbidly obese frequently present with mood and anxiety disorders, which are often treated with serotonin reuptake inhibitors (SRI) antidepressant drugs. The investigators hypothesized that gastric bypass surgery would decrease the absorption of SRI. The investigators also wished to determine whether a reduction in SRI levels would increase the likelihood of worsening depressive symptoms.

Twelve RYGB candidates who were successfully treated with an SRI for primary mood or anxiety disorders were studied prospectively. Blood samples for SRI plasma levels were drawn immediately after dose for pharmacokinetic studies (PK) preoperatively. Maximum concentration (CMAX), time to CMAX (TMAX), and Area Under Concentration/Time curve (AUC) were determined. PK studies were repeated at one, six, and twelve months post-operatively. PK data were corrected for dose at each study time point. The Structured Interview Guide for the Hamilton Depression Rating Scale- Atypical Depression Symptom Version was used to quantify depressive symptoms.

Inclusion Criteria:

• Able to tolerate general anesthesia
• Able to document prior unsuccessful attempts at weight loss under medical supervision during the last 6 months
• Able to provide informed consent
• Cleared for surgery by primary care MD, dietician, and psychiatrist
• SRI treatment specifically for depression for ≥6 wks at constant dose for last 2 out of 6 wks

Exclusion Criteria:

• pregnancy
• Unwilling or unable to comply with postoperative requirements for diet, supplements, exercise, or followup

Bariatric surgery clinic- Morbidly obese patients seeking RYGB who met criteria for bariatric surgery (BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with severe obesity-related comorbidities) and were received maintenance treatment with an SRI for primary mood or anxiety disorder.