Folic acid/methylfolate for the treatment of psychopathology in schizophrenia: a systematic review and meta-analysis

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#antipsychotic-agents #depression #double-blind-method #drug-therapy-combination #folic-acid

Folic acid/methylfolate for the treatment of psychopathology in schizophrenia: a systematic review and meta-analysis

Sakuma et al., 2018 | Psychopharmacology (Berl) | Meta Analysis

Citation

Sakuma Kenji, Matsunaga Shinji, ... Iwata Nakao. Folic acid/methylfolate for the treatment of psychopathology in schizophrenia: a systematic review and meta-analysis. Psychopharmacology (Berl). 2018-Aug;235(8):2303-2314. doi:10.1007/s00213-018-4926-4

Abstract

RATIONALE: This study aims to examine whether folate/folic acid/methylfolate/folinic acid supplemented to antipsychotics (FA + AP) is beneficial in schizophrenia treatment. OBJECTIVE: We conducted a comprehensive systematic review and meta-analysis of double-blind, placebo-controlled, randomized clinical trials (RCTs) of FA + AP for schizophrenia. METHODS: The primary outcome was an improvement in total symptoms. Other outcomes were psychopathology subscales (positive, negative, general, and depressive symptoms), discontinuation due to all-cause and adverse events, and individual adverse events. The meta-analysis evaluated the effect size based on a random-effects model. RESULTS: Although we included ten RCTs with 925 patients in total (seven folic acid RCTs (n = 789), two methylfolate RCTs (n = 96), and one folinic acid RCT (n = 40)) in the systematic review, only seven RCTs were included in the meta-analysis. Pooled FA + AP treatments were not superior to placebo + AP in the improvement of total (N = 7, n = 340; standardized mean difference (SMD) = - 0.20, 95% confidence interval (CI) = - 0.41, 0.02, p = 0.08, I2 = 0%), positive, general, or depressive symptoms. Pooled FA + AP treatments were more effective than placebo + AP for negative symptoms (N = 5, n = 281; SMD = -0.25, 95% CI = -0.49, -0.01, p = 0.04, I2 = 0%). Although pooled FA + AP treatments were associated with a lower incidence of serious adverse events than placebo treatments (N = 4, n = 241; risk ratio = 0.32, 95% CI = 0.12-0.82, p = 0.02, I2 = 0%; number needed to harm = not significant), there were no significant differences in other safety outcomes between both treatments. CONCLUSIONS: Our findings suggest that pooled FA + AP treatment improves negative symptoms in schizophrenia patients. Moreover, this treatment was well tolerated. However, because our results might exhibit a small-study effect, future studies with a larger sample should be conducted to obtain more robust results.

Key Findings

Although we included ten RCTs with 925 patients in total (seven folic acid RCTs (n = 789), two methylfolate RCTs (n = 96), and one folinic acid RCT (n = 40)) in the systematic review, only seven RCTs were included in the meta-analysis. Pooled FA + AP treatments were not superior to placebo + AP in the improvement of total (N = 7, n = 340; standardized mean difference (SMD) = - 0.20, 95% confidence interval (CI) = - 0.41, 0.02, p = 0.08, I2 = 0%), positive, general, or depressive symptoms. Pooled

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 789
Age Range See abstract
Condition See abstract

MeSH Terms

  • Antipsychotic Agents
  • Depression
  • Double-Blind Method
  • Drug Therapy, Combination
  • Folic Acid
  • Humans
  • Psychopathology
  • Randomized Controlled Trials as Topic
  • Schizophrenia
  • Schizophrenic Psychology
  • Tetrahydrofolates
  • Treatment Outcome

Evidence Classification

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

Provenance

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