Major Depressive Disorder (MDD) is strongly associated with suicidal behavior. Thyroid dysfunction and autoimmunity have been implicated through immuno-inflammatory (↑IL-1β/IL-6/TNF-α) and neurotrophic (BDNF) pathways. Levothyroxine and antidepressants may influence these biomarkers, affecting clinical response. This paper investigated associations between psychometric scales and biochemical, hormonal, hematological, and clinical features to better characterize suicide risk and treatment outcomes in MDD. Thirty-four MDD patients from UBS 17 (Planaltina-DF) and UBS 3 (Samambaia-DF) completed the Beck Depression Inventory (BDI) and Beck Scale for Suicide Ideation (BSS). Clinical data and blood samples were collected for biochemical and hormonal analysis. The study was approved by CEP-FEPECS and CONEP (CAAE 22434819.0.0000.8093). Data were analyzed using SPSS v.28 (α = 5%). BDI scores moderately correlated with total BSS scores (ρ = 0.563; p < 0.001). Associations between BDI and BSS TeS were weak (ρ = 0.249; p = 0.155) with a trend between BSS total and BSS TeS (ρ = 0.303; p = 0.081). Patients without clinical improvement showed higher BSS scores (median 7 vs. 4; p ≈ 0.05–0.10). In a subsample (≈13), higher BSS TeS correlated with lower segmented neutrophils, reduced absolute bands, and lymphocytosis. Free T4 was inversely associated with BSS TeS (ρ = −0.630; p = 0.021). Glycemia, HbA1c, and lipid levels showed no consistent links. Integrating BDI and BSS enhances suicide risk stratification in MDD. Blood counts and free T4 levels may serve as exploratory markers for monitoring thyroid function. Larger studies are required to validate results.
Author Contributions
Conceptualization, G.F.M. and I.C.R.S.; methodology, I.C.R.S., G.F.M. and M.M.G.P. software, C.M.S.S., G.F.M. and I.C.R.S.; validation, G.F.M., I.C.R.S. and A.A.F.S.; formal analysis, G.F.M., A.P.B., A.A.F.S. and I.C.R.S.; investigation, M.A.P. and A.S.R.P.; resources, I.C.R.S.; data curation, M.A.P. and C.F.F.; writing—original draft preparation, G.F.M. and I.C.R.S.; writing—review and editing, A.P.B.; visualization, L.S.S.B.; supervision, C.F.F. and I.C.R.S.; project administration, I.C.R.S., A.A.F.S. and G.F.M.; funding acquisition, I.C.R.S. and A.S.R.P. All authors have read and agreed to the published version of the manuscript.
Funding
CAPES—Finance Code: 001; SEI nº 00193-00002187/2023-24–Notice 09/2023–Spontaneous Demand FAPDF and the National Council for Scientific and Technological Development (CNPq) with the Ministry of Health/Department of Science and Technology (MS/Decit), Finance Code: 444755/2023-3.
Institutional Review Board Statement
The study followed the principles of the Declaration of Helsinki and was approved by Institutional Ethics Committee of FCE, Research Ethics Committee for Human Subjects of FEPECS (CEP-FEPECS), and the National Research Ethics Commission (CONEP), under protocol number 22434819.0.0000.8093 on 27 November 2024.
Informed Consent Statement
Informed consent was obtained from all subjects involved in the study.
Data Availability Statement
The datasets generated and/or analyzed during the current study are not publicly available due to privacy restrictions but are available from the corresponding author on reasonable request.
Conflicts of Interest
The authors declare no conflict of interest.
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