Zinc for Depression
Verdict: Published with Warning
Across 6 PubMed studies, the evidence for Zinc in Depression grades Tier B — preliminary evidence. Effective, but with safety or population caveats.
B 🟡 B Preliminary Evidence Published with Warning
Why this grade7-layer evidence engine
⚖️
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.63
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
B · Published with Warning
Confidence
81%
Highly consistent evidence
Evidence level
E2
Multiple high-quality MAs (≥2 independent, consistent)
▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.627
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (2 篇 > 0 negative)
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status
PubMed studies (6)L2 · primary research & systematic reviews
Zinc supplementation combined with antidepressant drugs for treatment of patients with depression: a systematic review and meta-analysis
Finding: Zinc reduced depressive symptoms versus placebo (SMD -0.36, 95% CI -0.67 to -0.04), with a larger effect in those aged 40+ (SMD -0.61, 95% CI -1.12 to -0.09).
View on PubMed Zinc as an adjunct to antidepressant medication: a meta-analysis with subgroup analysis for different levels of treatment response to antidepressants
Finding: Adjunctive zinc lowered HDRS scores versus placebo at 6 weeks (Hedges' g = -0.67, p = 0.03) and 12 weeks (Hedges' g = -1.0, p = 0.03), with stronger effects in the treatment-resistant subgroup.
View on PubMed Zinc in depression: From development to treatment: A comparative/ dose response meta-analysis of observational studies and randomized controlled trials
Finding: Highest vs lowest zinc intake was associated with 28% lower depression risk (RR 0.66, 95% CI 0.50-0.82), and zinc monotherapy lowered symptom scores (WMD -4.15 points, 95% CI -6.56 to -1.75, p<0.01).
View on PubMed The efficacy of zinc supplementation in depression: systematic review of randomised controlled trials
Finding: Zinc significantly lowered depressive symptom scores when used as an adjunct to antidepressants, but evidence for zinc alone in non-depressed/healthy subjects was unclear (qualitative synthesis; no pooled estimate due to heterogeneity).
View on PubMed Zinc in depression: a meta-analysis
Finding: Depressed subjects had lower blood zinc than controls (difference -1.85 µmol/L, 95% CI -2.51 to -1.19, p<0.00001), with greater severity linked to lower zinc; this is an association of zinc status, not evidence that supplementation treats depression.
View on PubMed Effects of zinc supplementation in patients with major depression: a randomized clinical trial
Finding: Adjunctive zinc (25 mg/day, 12 weeks) significantly reduced BDI scores versus placebo at week 12 (p<0.05) in patients with major depression.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4b EU EFSA
Supportive
contributes to normal function of the immune system source↗
L4c UK NHS
Cautious
You should be able to get all the zinc you need from your daily diet source↗
L4d TW TFDA / 衛福部
Supportive
鋅之每日最高攝食量不得超過30 mg source↗
L4e WHO
Supportive
zinc has been recommended by WHO and UNICEF as the only treatment to be coupled with oral rehydration salts for the treatment of all diarrhoea episodes source↗
L5a NIH Office of Dietary Supplements
Supportive
Zinc is an essential mineral involved in numerous aspects of cellular metabolism source↗
L5b Mayo Clinic
Neutral
People who have low levels of zinc seem to benefit most from zinc supplements. Zinc supplements are used to prevent or treat zinc deficiency. Don't use a zinc supplement that's placed into the nose, called intranasal zinc. This form of zinc has been linked to loss of the sense of smell. source↗
L5c Cleveland Clinic
Neutral
The most studied options highlighted as potentially effective include: exercise, L-Methylfolate, Omega-3 (fish oil), probiotics, saffron, SAM-e, and Vitamin D. [Zinc is not mentioned among the recommended natural antidepressants on Cleveland Clinic's Natural Antidepressants page, nor is depression listed among zinc's benefits on the Zinc benefits page, which lists: shortens cold duration, prote… source↗
L5e Specialty Society (condition-mapped)
Cautious
The FDA has not approved any natural products for treating depression. Although research is ongoing and findings are inconsistent, some people report that natural products, including vitamin D and the herbal dietary supplement St. John's wort, helped their depression symptoms. However, these products can come with risks, including, in some cases, interactions with prescription medications. source↗