Clinical Trials and References

Review Article: Homocysteine and folate metabolism in depression
Teodoro Bottiglieri
Baylor University Medical Center, Institute of Metabolic Disease, Dallas, Texas 75226, USA

Abstract
Homocysteine is a sensitive marker of folate and vitamin B12 deficiency. Numerous studies have confirmed the association between folate deficiency and depression. It is not completely understood whether homocysteine is solely a marker for folate deficiency or if it may play a more direct role in the expression of mood disorders. This review describes the biochemical, neurochemical and clinical correlations of folate deficiency and hyperhomocysteinemia in relation to depression.

© 2005 Elsevier, Inc. All rights reserved.

Keywords: Depression; Folate; Homocysteine; Methylation; VitaminB6; VitaminB12


Folic acid enhances lithium prophylaxis.
Coppen A, Chaudhry S, Swade C; J Affect Disord. 1986 Jan-Feb;10(1):9-13. N = 75; Compound: Folic acid @ 200µg/day

A double-blind trial was carried out to investigate the effect on affective morbidity of a daily supplement of 200 µg of folic acid or a matched placebo in a group of 75 patients on lithium therapy. During the trial the patients with the highest plasma folate concentrations showed a significant reduction in their affective morbidity. Patients who had their plasma folate increased to 13 ng/mL or above had a 40% reduction in their affective morbidity. It is suggested that a daily supplement of 300-400 µg of folic acid would be useful in long-term lithium prophylaxis.


Enhancement of recovery from psychiatric illness by methylfolate.
Godfrey P.S.A, Toone B.K., Carney M.W.P., Flyn T.G., Bottglieri T., Laundy M., Reynolds E.H; Lancet. 1990 Aug 18;336(8712):392-5.
N = 123; Compound: 6(R,S)-5MTHF @ 15mg/day

41 (33%) of 123 patients with acute psychiatric disorders (DSM III diagnosis of major depression or schizophrenia) had borderline or definite folate deficiency (red-cell folate below 200µg/L) and took part in a double-blind, placebo-controlled trial of methylfolate, 15 mg daily, for 6 months in addition to standard psychotropic treatment. Among both depressed and schizophrenic patients methylfolate significantly improved clinical and social recovery. The differences in outcome scores between methylfolate and placebo groups became greater with time. These findings add to the evidence implicating disturbances of methylation in the nervous system in the biology of some forms of mental illness.


An open trial of methyltetrahydrofolate in elderly depressed patients.
Guaraldi GP, Fava M, Mazzi F, la Greca P; Ann Clin Psychiatry. 1993 Jun;5(2):101-5.
N = 20; Compound: 6(R,S)-5MTHF @ 50mg/day

5-methyltetrahydrofolate (MTHF) is a naturally occurring substance involved in the synthesis of s-adenosyl-l-methionine (SAMe), a major source of methyl groups in the brain. To assess the eficacy of a gastro-resistant, oral preparation of MTHF, 20 elderly patients with a DSM-III-R diagnosis of depressive disorder and a HAM-D-21 score > 18 underwent 6-weeks of open-label treatment with 50 mg per day of oral MTHF. Of these 20 patients, 16 completed at least 4 weeks of treatment and showed a markedly significant improvement in their depressive symptoms at endpoint, with 81% of them being considered responders. There were no clinically relevant changes in the routine laboratory tests during the study, and no adverse events considered to be definitely drug-related were reported.


Oral 5-methyltetrahydrofolic acid in senile organic mental disorders with depression: results of a double-blind multi-center study.
Passeri M, Cucinotta D, Abate G, Senin U, Ventura A, Stramba Badiale M; .Aging, 1993 Feb;5(1):63-71.
N = 96; Compound: 6(R,S)-5MTHF @ 50mg/day

5'-Methyltetrahydrofolic acid (5'-MTHF) in addition to standard psychotropic medication significantly improved clinical recovery in depressed patients with borderline or definite folate deficiency, and significantly reduced depressive symptoms in elderly normofolatemic patients after 3 weeks of treatment. In this equivalence study the effect of 5'-MTHF on depressive symptoms and cognitive status was compared to Trazodone (TRZ) in normofolatemic elderly patients with mild to moderate dementia and depression. Ninety-six patients with dementia, scoring 12-23 at the Mini Mental State Examination (MMSE) and > 18 at the Hamilton Depression Rating Scale (HDRS) after a 2-week placebo run-in, were randomized to receive either 5'-MTHF (50 mg/day p.o.) (47 patients) or TRZ (100 mg/day p.o.) (49 patients) in a double-blind design for 8 weeks. HDRS was assessed before, after 4 weeks and at the end of treatment; Rey's Verbal Memory (RVM) test for immediate and delayed recall was evaluated before and after treatment. After 4 weeks of treatment HDRS score was reduced from 23 ± 5 to 20 ± 6 in the 5'-MTHF (p < 0.05 vs. baseline), and from 23 ± 3 to 21 ± 4 in the TRZ group (p < 0.05 vs. baseline). A further signiicant decrease to 18 ± 6 and 19 ± 5 respectively was obtained at the end of the treatment period (p < 0.05 vs. week 4) with 5'-MTHF and TRZ. HDRS was administered again after a 4-week, drug free, follow-up period: no change vs. the post treatment scores were observed either in the 5'-MTHF or in the TRZ group (18+7and 19+5 respectively). RVM test for immediate recall was significantly improved (p7lt;0.05) at week 8 vs. baseline in the 5'-MTHF group whereas no significant change occurred in the TRZ group. No change in delayed recall was observed after treatment in either group. Tolerability was good for both treatments. This study showed that 5'-MTHF and TRZ are equally effective in improving depressive symptoms in patients with mild to moderate dementia and suggests that pharmacological doses of 5'-MTHF may exert psychotropic effects irrespective of folate status.


Is methylfolate effective in relieving major depression in chronic alcoholics? A hypothesis of treatment
C. Di Palma, R. Urani, R. Agricola, V. Giorgetti and G. Dalla Verde; Current Therapeutic Research; Volume 55, Issue 5 , May 1994, Pages 559-568
N = 36; Compound: 6(R,S)-5MTHF @ 90mg/day

Folate deficiency is often associated with depression. Chronic alcoholics, who usually present with reduced blood folate levels, are frequently affected by depression. After a 1-week run-in placebo period, 36 chronic alcoholics with major depression were treated with methylfolate (90 mg/d orally for 4 weeks) as an antidepressant. The surprisingly beneficial effects induced by methylfolate on depressive signs and symptoms of ethanol abusers should encourage more extensive experimental and clinical investigations to confirm these preliminary results. No adverse side effects were reported.


Enhancement of the antidepressant action of fluoxetine by folic acid: a randomized, placebo controlled trial
Coppen A., Bailey J.; Journal of Affective Disorders, Volume 60, November 2000, Pages 121-130
N = 127; Compound: Folic acid @ 0.5mg/day

Background: A consistent finding in major depression has been a low plasma and red cell folate which has also been linked to poor response to antidepressants. The present investigation was designed to investigate whether the co-administration of folic acid would enhance the antidepressant action of luoxetine.

Methods: 127 patients were randomly assigned to receive either 500 mg of folic acid or an identical looking placebo in addition to 20 mg fluoxetine daily. All patients met the DSM-III-R criteria for major depression and had a baseline Hamilton Rating Scale (17 item version) score for depression of 20 or more. Baseline and 10-week estimations of plasma folate and homocysteine were carried out.

Results: Patients receiving folate showed a significant increase in plasma folate. This was less in men than in women. Plasma homocysteine was significantly decreased in women by 20.6%, but there was no signiicant change in men. Overall there was a significantly greater improvement in the luoxetine plus folic acid group. This was confined to women where the mean Hamilton Rating Scale score on completion was 6.8 (S.D. 4.1) in the luoxetine plus folate group, as compared to 11.7 (S.D. 6.7) in the fluoxetine plus placebo group (P<0.001). A percentage of 93.9 of women, who received the folic acid supplement, showed a good response (>50% reduction in score) as compared to 61.1% of women who received placebo supplement (P<0.005). Eight (12.9%) patients in the fluoxetine plus folic acid group reported symptoms possibly or probably related to medication, whereas in the luoxetine plus placebo group 19 (29.7%) patients reported such symptoms (P<0.05).

Limitations and conclusions: Folic acid is a simple method of greatly improving the antidepressant action of fluoxetine and probably other antidepressants. Folic acid should be given in doses sufficient to decrease plasma homocysteine. Men require a higher dose of folic acid to achieve this than women, but more work is required to ascertain the optimum dose of folic acid.


Folinic acid (Leucovorin) as an adjunctive treatment for SSRI-refractory depression.
Alpert JE, Mischoulon D, Rubenstein GE, Bottonari K, Nierenberg AA, Fava M. Ann Clin Psychiatry. 2002 Mar;14(1):33-8.
N = 22; Compound: 6(R,S)-5FTHF @ 15-30mg/day

Low folate is associated with poorer response to selective serotonin reuptake inhibitors (SSRIs) in major depressive disorder (MDD). Folate supplementation in MDD has been studied in other settings with promising results. The objective of this study was to assess the efficacy of methylfolate as an adjunctive treatment among adults with MDD and inadequate response to an SSRI. Twenty-two adults (59% female; mean age 45.2 ± 11.0 years) with DSM-IV MDD, partial or nonresponse to an SSRI after at least 4 weeks of treatment, and a 17-item Hamilton Depression Rating Scale (HAM-D-17) score > 12 were enrolled in this 8-week prospective open trial. Exclusion criteria included current use of anticonvulsants or psychotropics other than an SSRI, or B12 deiciency. Leucovorin (folinic acid), which is metabolized to methylfolate, was added to SSRIs at 15-30 mg/day. Folate levels rose from 28 ± 19 ng/mL to 301 ± 203 ng/mL (p < 0.001). HAM-D-17 scores among the 16 completers decreased from 19.1 ± 3.9 to 12.8 ± 7.0 (p < 0.01). However only 31% of completers and 27% of the intent-to-treat (ITT) sample achieved response (> 50% reduction in HAM-D-17 scores), and only 19% of completers and 18% of the ITT sample achieved remission (HAM-D-17 < 7). Leucovorin appears to be modestly effective as an adjunct among SSRI-refractory depressed individuals with normal folate levels. The application of Leucovorin as an adjunct in the setting of refractory depression deserves further study.