TRANSMETHYLATION AND AFFECTIVE-DISORDERS

S-adenosyl-L-methionine (SAMe) is a naturally occurring metabolite and a major source of methyl groups in the brain. Methylation processes a re important in the expression of mood and the failure of methylation may underlie some affective disorders. The administration of SAMe is a ssociated with an increase in both 5-OH-indoleacetic acid and homovani llic acid, being the metabolites of serotonin and dopamine, respective ly. SAMe indices mood elevation in depressed patients. Until 1995, 1,4 00 patients treated with SAMe were investigated in open or controlled trials. The efficacy of SAMe in treating depressive disorders is super ior to placebo and comparable to standard tricyclic antidepressants. S AMe demonstrates a particularly low side effect profile. The increase of anxiety is the most common side effect. The addition of SAMe to sta ndard antidepressants may shorten the time of treatment response compa red to the use of antidepressants alone, especially in pa;enteral use (400-800 mg/day, iv.).