Serum and red cell folate concentrations in outpatients receiving lithium carbonate

Homocysteine as a peripheral biomarker in bipolar disorder: A meta-analysis

Background:

Bipolar disorder (BD) is a psychiatric disorder with an uncertain aetiology. Recently, special attention has been given to homocysteine (Hcy), as it has been suggested that alterations in 1-carbon metabolism might be implicated in diverse psychiatric disorders. However, there is uncertainty regarding possible alterations in peripheral Hcy levels in BD.

Methods:

This study comprises a meta-analysis comparing serum and plasma Hcy levels in persons with BD and healthy controls. We conducted a systematic search for all eligible English and non-English peer-reviewed articles.

Results:

Nine cross-sectional studies were included in the meta-analyses, providing data on 1547 participants. Random-effects meta-analysis showed that serum and plasma levels of Hcy were increased in subjects with BD in either mania or euthymia when compared to healthy controls, with a large effect size in the mania group (g= 0.98, 95% CI: 0.8–1.17,P< 0.001,n= 495) and a small effect in the euthymia group (g= 0.3, 95% CI: 0.11–0.48,P= 0.002,n= 1052).

Conclusions:

Our meta-analysis provides evidence that Hcy levels are elevated in persons with BD during mania and euthymia. Peripheral Hcy could be considered as a potential biomarker in BD, both of trait (since it is increased in euthymia), and also of state (since its increase is more accentuated in mania). Longitudinal studies are needed to clarify the relationship between bipolar disorder and Hcy, as well as the usefulness of peripheral Hcy as both a trait and state biomarker in BD.

Folic acid efficacy as an alternative drug added to sodium valproate in the treatment of acute phase of mania in bipolar disorder: a double-blind randomized controlled trial

OBJECTIVE

The purpose of this study was to evaluate the efficacy of adding folic acid to sodium valproate in the acute phase of mania.

METHOD

Following a double-blind randomized controlled trial, 88 clinically manic patients with diagnosis of type I bipolar disorder (BID) were divided randomly into two groups (case and control). The case group was treated with folic acid and sodium valproate and the control group with sodium valproate and placebo. The severity of mania was assessed using the Young Mania Rating Scale (YMRS) at the beginning and end of the first, second and third weeks of the study.

RESULTS

The case group's mean manic YMRS measurements (SD) before the initiation of therapy and in the first, second and third weeks of treatment were 34.0 +/- 7.7, 26.7 +/- 2.1, 18.1 +/- 2.1 and 7.1 +/- 0.9 respectively. The control group's measurements were 34.7 +/- 3.8, 27.3 +/- 2.3, 20.7 +/- 2.5 and 10.1 +/- 1.1. There was a statistically significant difference in YMRS scaling results between the case and control groups after 3 weeks of treatment (7.1 +/- 0.9 vs. 10.1 +/- 1.1, P = 0.005).

CONCLUSION

Based on our findings, folic acid seems to be an effective adjuvant to sodium valproate in the treatment of the acute phase of mania in patients with bipolar disorder.

A controlled study of folate levels in Chinese inpatients with major depression in Hong Kong

BACKGROUND

Although Western and, in particular, British studies have revealed a substantial rate of hypofolatemia in patients with depression, few such studies have been conducted in Asian populations.

METHODS

A group of 117 newly admitted inpatients with DSM-III-R major depression and 72 healthy controls underwent blood investigations and psychometric assessments.

RESULTS

Patients had a significantly lower mean serum folate level (24.6+/-10.2 vs. 30.3+/-11.4 nmol/l, P < 0.001) but a higher mean erythrocyte folate level (801.8+/-284.6 nmol/l vs. 699.5+/-248.7 nmol/l, P < 0.01) than control subjects. No patient or control subjects had low folate, while only four patients (3.4%) and six control subjects (8.3%) had low erythrocyte folate. Folate levels were not related to patients' age, duration of illness, Hamilton Depression Rating Scale, Beck Depression Inventory and Global Assessment Scale scores, and prior psychotropic drug usage. Both patients and control subjects revealed a high intake of green vegetables.

CONCLUSION

Patients' lower serum folate level was likely to be secondary to their depression but, being well in the normal range, should not have aggravated their depressive symptoms. Culturally patterned health beliefs and dietary practices can influence the connection between folate status and depression in different societies.

LIMITATIONS

Patients were not drug-free, while the lack of detailed dietary analysis and longitudinal data on folate level and psychiatric outcome tempered the above conclusion.

CLINICAL RELEVANCE

Since normofolatemia is normative in Hong Kong, the routine screening of folate levels in Chinese depressive patients is not indicated. However, a double-blind, placebo-controlled trial may be useful for finding out whether Chinese patients will still benefit from folate pharmacotherapy.

Folate concentration in Chinese psychiatric outpatients on long-term lithium treatment

Among 46 Chinese and mostly manic-depressive (85%) outpatients attending a lithium clinic in Hong Kong, virtually no patients had low serum (0%) or erythrocyte (2%) folate. Their mean folate levels did not differ from lithium-free outpatients. Although serum folate correlated negatively with lithium dose (P less than 0.002) and serum level (P less than 0.01), lithium treatment probably did not by itself cause low folate. Folate level was not related to diagnosis, duration of mental illness, other drug usage or spot affective morbidity. Patients with a good response to lithium in the previous one year had a higher mean serum folate level than those with unsatisfactory response (P less than 0.05). These data suggest that folate deficiency is uncommon among Chinese psychiatric outpatients, but support recent evidence that folate at high concentrations enhances lithium prophylaxis.

Serum and red cell folate and affective morbidity in lithium prophylaxis

Serum and red cell folate concentrations were estimated in 68 affective disorder patients taking lithium prophylactically, 65 of whom had bipolar disorder. The number of hospital admissions, the frequency of use of additional mood altering treatments and the Affective Morbidity Index were calculated for the 2 years of the study. Contrary to other findings, there were no differences between the folate concentrations for different severities of affective morbidity. These results question the rationale of prescribing folic acid preparations for lithium-treated bipolar disorder patients, but the authors indicate that folate concentrations may be low in lithium-treated unipolar depressives.

Vitamin deficiency and mental symptoms

Recently, research into the connection between vitamins and psychiatric disorder, particularly affective changes, has been in the doldrums, with the exceptions perhaps of studies of folic acid and pyridoxine. The best way for research to proceed is first to establish that the association of a vitamin deficiency with a psychiatric disorder is beyond a chance finding. Then, questions should be asked about what mental symptoms it is linked with, and what the other associations (malnutrition, drugs, physical illness, etc) are. Lastly, queries should be raised about whether the association is causal or if the mental symptoms are merely secondary to the anorexia and poor diet so common in mental illness (or whether they are linked in a vicious circle as suggested by Reynolds et al (1971)). These questions became pertinent in the mid-1960s when reliable ways of assaying B vitamins such as folic acid became more generally available. In this review, I present evidence that deficiencies of folic acid, B12, thiamine, riboflavin, pyridoxine and ascorbic acid are not infrequently found in psychiatric practice. It should be remembered, however, that some ways of assaying vitamins are liable to give a larger proportion of spurious low results than other methods (false positives), although the adoption of more reliable ways of assaying vitamins should reduce this.