Wellbutrin XL Effects on SSRIs Induced Changes

The purpose of this study is to find out differences in activation of mood regulating areas of the brain in response to negative and positive pictures, before and after 6 weeks of additional Wellbutrin XL treatment. Participants should have been treated for depression with an SSRI medication (e.g., Prozac, Zoloft, Paxil, Celexa or Lexapro) and have decreased depression symptoms but also be experiencing side effects of medications such as sexual side effects and feelings of apathy (indifference, lack of interest) and lack of full emotional response. We will first take a brain scan to measure activity in different parts of the brain, while subjects are seeing pictures, using Magnetic Resonance Imaging (MRI) scan. Then we will add Wellbutrin XL - another well-known antidepressant that acts by increasing the chemical dopamine in the brain, to subjects' treatment. Wellbutrin addition is useful in decreasing the sexual side effects of SSRIs. After treatment with Wellbutrin XL for 6 weeks subjects will have a second MRI scan with picture rating.

Hypotheses: Hypothesis 1.After wellbutrin XL addition for 6 weeks, SSRI treated subjects will show increased activation and connectivity of prefrontal cortex and limbic regions such as the amygdala on exposure to negative and positive pictures Hypothesis 2.Increase in activation of the MRC (Mood Regulating Circuit) will correlate with decrease in Apathy Evaluation Scale (AES) score and Sexual Dysfunction Score. We plan to study a maximum of 15 subjects in this study. SSRI treated depressed patients who after treatment of depression continue to suffer from sexual dysfunction and apathy will be included in the study. fMRI will be conducted at baseline and after addition of Wellbutrin XL treatment 300 mg po qd and then used at a dose of 300 mg - 450 mg from week 3 - 6 depending on response and tolerance. Patients will also be rated weekly on 17-item Hamilton Depression Rating Scale, Montgomery-Asberg Depression Rating Scale (MADRAS) (Montgomery and Asberg 1979), AES (Marin et al 1991), Changes in Sexual Functioning Questionnaire (CSFQ) and Clinical Global Impression (Improvement) weekly for 6 weeks. Depressed patients will also be rated on the scan days on cognitive measures such as verbal memory and working memory.