The association of folate and depression: A meta-analysis

source extracted confidence: high 2026-04-09
#adolescent #adult #aged #child #depression

The association of folate and depression: A meta-analysis

Bender et al., 2017 | J Psychiatr Res | Meta Analysis

Citation

Bender Ansley, Hagan Kelsey E, Kingston Neal. The association of folate and depression: A meta-analysis. J Psychiatr Res. 2017-Dec;95:9-18. doi:10.1016/j.jpsychires.2017.07.019

Abstract

BACKGROUND: Previous research suggested that folate levels play an important role in the etiology and course of depression. However, the literature has been inconsistent with regard to differences in folate level between individuals with and without depression. The present meta-analysis synthesized the results of previous studies to examine whether individuals with depression had lower levels of folate than individuals without depression. METHODS: Meta-analytic procedures were conducted in accordance with PRISMA guidelines. Studies evaluating folate levels in individuals with and without depression via red blood cell folate, serum folate, or dietary intake of folate methods were identified via PsycINFO and PubMed. Random-effects meta-analysis was conducted using Hedge's g, and moderation analysis was used for both folate measurement method and population type. Study heterogeneity was assessed with I2 and publication bias was qualitatively assessed via funnel plot and quantitatively assessed with the trim-and-fill method and Begg's adjusted rank test. RESULTS: We found a significant, small effect size, such that individuals with depression had lower folate levels than those without depression, Hedge's g = -0.24 (95% CI = -0.31, -0.16), p < 0.001. Study heterogeneity was high (I2 = 84.88%), and neither folate measurement method nor population accounted for study heterogeneity. CONCLUSIONS: Individuals with depression have lower serum levels of folate and dietary folate intake than individuals without depression. Given that previous literature suggested folate supplementation improved the efficacy of traditional antidepressant medications, future research on folate supplementation in depression is warranted and clinicians may wish to consider folate supplementation for patients with depression.

Key Findings

We found a significant, small effect size, such that individuals with depression had lower folate levels than those without depression, Hedge's g = -0.24 (95% CI = -0.31, -0.16), p < 0.001. Study heterogeneity was high (I2 = 84.88%), and neither folate measurement method nor population accounted for study heterogeneity.

Outcomes Measured

  • depression

Population

Field Value
Population and without depression
Sample Size See abstract
Age Range See abstract
Condition depression

MeSH Terms

  • Adolescent
  • Adult
  • Aged
  • Child
  • Depression
  • Depressive Disorder
  • Folic Acid
  • Humans
  • Middle Aged
  • Vitamin B Complex
  • Young Adult

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis, Review
  • Vertical: folate

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09