Hypothalamic-pituitary-thyroid axis dysregulation in adolescents with major depressive disorder and non-suicidal self-injury: A retrospective study.

BACKGROUND

Non-suicidal self-injury (NSSI) is prevalent in adolescents with major depressive disorder (MDD), yet the neuroendocrine mechanisms underlying NSSI remain poorly understood. This study examined the associations between hypothalamic-pituitary-thyroid (HPT) axis parameters, NSSI, and clinical symptoms in adolescents with MDD.

METHODS

In this retrospective study, 110 adolescents with MDD (aged 12-17 years) were categorized into NSSI n = 45) and non-NSSI (n = 65) groups. Serum thyroid hormones (TSH, T3, T4, FT3, FT4) were measured via electrochemiluminescence immunoassay. Covariate-adjusted analyses compared thyroid function between groups and evaluated correlations with anxiety (HAMA) and depression (HAMD-24) symptom domains.

RESULTS

After adjusting for age, gender, BMI, illness duration, and antidepressant dose, the NSSI group exhibited significantly higher free thyroxine (FT4) levels compared to non-NSSI controls (17.01 ± 2.22 vs. 15.91 ± 2.25 pmol/L; p = 0.029). No differences were observed in TSH, T3, T4, FT3, or FT3/FT4 ratio (p > 0.05). Within the NSSI group, FT3 negatively correlated with somatic anxiety (r = -0.307, p = 0.040), while T4 inversely associated with psychomotor retardation (r = -0.299, p = 0.046).

CONCLUSION

Elevated FT4 levels suggest potential HPT axis dysregulation that may be associated with NSSI in adolescents with MDD. FT3 inversely correlated with somatic anxiety and T4 with psychomotor retardation, suggesting that thyroid hormones may play differential modulatory roles within depressive pathology.