Thyroid dysfunction and Research Domain Criteria framework-based depression phenotypes: Insights from a historical...

Area of Science:

• Neuroendocrinology
• Psychiatry
• Clinical Research

Background:

• Depression is a complex disorder with unclear biological mechanisms.
• The hypothalamic-pituitary-thyroid axis may be implicated in depression pathophysiology.
• The Research Domain Criteria (RDoC) framework offers a dimensional approach to understanding depression.

Purpose of the Study:

• To investigate the association between thyroid-stimulating hormone (TSH) abnormalities and depressive symptoms.
• To map depressive symptoms onto RDoC domains to identify specific symptom clusters related to thyroid function.

Main Methods:

• Retrospective cohort study of adults with baseline euthyroid status.
• Analysis of paired TSH and Patient Health Questionnaire-9 (PHQ-9) data.
• Linear mixed-effects models used to assess associations between TSH dysfunction and RDoC domain scores.

Main Results:

• Abnormal TSH levels (low or high) were significantly associated with higher scores in the Arousal/Regulatory (AR) Systems domain.
• No significant associations were found between abnormal TSH and other RDoC domains (Negative Valence-Externalizing, Negative Valence-Internalizing, Cognitive/Sensorimotor).

Conclusions:

• Findings support the use of biologically informed, dimensional frameworks like RDoC in depression research.
• Elevated AR Systems symptoms alongside abnormal TSH may indicate a distinct depression phenotype.
• Further research into the thyroid-depression link could inform personalized treatment strategies.