Effects of S-adenosylmethionine augmentation of serotonin-reuptake inhibitor antidepressants on cognitive symptoms of major depressive disorder

UNLABELLED: Major depressive disorder (MDD) is often accompanied by significant cognitive impairment, and there are limited interventions specific to this particular symptom. S-adenosylmethionine (SAMe), a naturally occurring molecule which serves as a major methyl-donor in human cellular metabolism, is required for the synthesis and maintenance of several neurotransmitters that have been implicated in the pathophysiology and treatment of cognitive dysfunction in MDD. OBJECTIVES: This study is a secondary analysis of a clinical trial involving the use of adjunctive SAMe for MDD. METHODS: Forty-six serotonin-reuptake inhibitor (SRI) non-responders with MDD enrolled in a 6-week, double-blind, randomized trial of adjunctive oral SAMe were administered the self-rated cognitive and physical symptoms questionnaire (CPFQ), a validated measure of cognitive as well as physical symptoms of MDD, before and after treatment. RESULTS: There was a greater improvement in the ability to recall information (P=0.04) and a trend towards statistical significance for greater improvement in word-finding (P=0.09) for patients who received adjunctive SAMe than placebo. None of the remaining five items reached statistical significance. CONCLUSIONS: These preliminary data suggest that SAMe can improve memory-related cognitive symptoms in depressed patients, and warrant replication.