Summary
| Direction in Major Depressive Disorder | ↑ Elevated — higher than in the comparison group |
|---|---|
| Category | Other |
| Compared against | normal reference range |
| Test type | Blood test (serum / plasma / whole blood) |
| LOINC code | 13965-9 |
| Source | Harikaran et al. 2024 — doi:10.4103/jfmpc.jfmpc_1460_23 |
| Condition atlas | Major Depressive Disorder Biomarker Atlas |
Other conditions where Homocysteine is reported
- Homocysteine in Alzheimer's Disease and Other Dementias — ↑ elevated vs healthy individuals
- Homocysteine in Gulf War Illness — ↑ elevated vs HGV
- Homocysteine in Migraine — ↑ elevated vs controls
See the cross-condition hub: Homocysteine across conditions.
Related Other markers in Major Depressive Disorder
- Dehydroepiandrosterone Sulfate (DHEA-S) ↕
- Insulin-like Growth Factor-1 (IGF-1) ↑
- Interleukin-1 beta ↑
- 25-Hydroxyvitamin D ↓
Full list: Major Depressive Disorder Biomarker Atlas.
Frequently asked questions
Is Homocysteine high or low in Major Depressive Disorder?
Elevated. Studies summarised in the OSMF atlas report higher Homocysteine in Major Depressive Disorder than in normal reference range. Source: Harikaran et al. 2024.
Which test measures Homocysteine?
It is measured as a blood test (serum / plasma / whole blood). The standard laboratory code is LOINC 13965-9. Many of the cited studies used research-grade assays, so clinical availability may vary.
Is one abnormal Homocysteine result diagnostic of Major Depressive Disorder?
No. No single biomarker is diagnostic of Major Depressive Disorder. Homocysteine findings come from group comparisons, overlap considerably between patients and controls, and vary with study design, timing and comparison group. A result should be interpreted by a clinician alongside symptoms, history and other tests.
Is Homocysteine specific to Major Depressive Disorder?
No. The same marker is also reported in Alzheimer's Disease and Other Dementias, Gulf War Illness, Migraine in this atlas, so it reflects shared biology (for example inflammation or vascular stress) rather than a condition-specific signature.
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Last reviewed: 2026-10-08 · Page generated from major-depressive-disorder.json · Browse: Major Depressive Disorder atlas · Biomarker Index · All marker pages
Disclaimer: This page is an educational synthesis of published, peer-reviewed research and is not medical advice. Biomarker findings vary across studies with case definitions, comparison groups, timing and assay methods. Direction of change reflects the predominant finding in the cited source and does not establish a diagnostic threshold. Discuss any test result with a qualified clinician.