Some people with depression do not respond well to antidepressant treatment. The purpose of this study is to determine whether adding another substance to an antidepressant drug treatment regimen can reduce depressive symptoms in patients currently taking antidepressant drugs but are not responsive to them.

S-adenosyl methionine (SAMe) is a naturally occurring compound that may have antidepressant effects. SAMe may also enhance the effectiveness of other antidepressants, such as selective serotonin reuptake inhibitors (SSRIs). This study will determine the effectiveness of oral SAMe in enhancing the effects of SSRIs in patients currently not responding to SSRI treatment.

This study will last 6 weeks. No follow-up visits will occur. Participants will be randomly assigned to add either oral SAMe or placebo to their existing SSRI regimen for 6 weeks. Depression scales and self-report questionnaires regarding depressive symptoms will be used to assess participants at the end of the study.

Ages Eligible for Study:  18 Years   -   80 Years,  Genders Eligible for Study:  Both

Criteria

Inclusion Criteria:

• Major depressive disorder
• Use of an SSRI for at least 6 weeks prior to study entry with partial or no response

Exclusion Criteria:

• History of psychosis
• Allergy to SAMe
• Alcohol or drug abuse in the past 3 months prior to study entry