Relationship Between Anxiety and Thyroid Dysfunction

Introduction to Comorbidity

Patients with anxiety disorders have a significantly increased likelihood of concomitant thyroid dysfunction, and this relationship is bidirectional, with routine thyroid screening recommended when treating anxiety disorders 1, 2

The comorbidity between anxiety disorders and thyroid disorders is statistically significant across both population-based and clinical samples, indicating this is not simply due to selection bias in treatment-seeking individuals 3
Anxiety disorders typically precede the onset of thyroid disorders in the majority of cases, which may indicate that subtle hypothalamic-pituitary-thyroid (HPT) axis alterations in anxious patients progress over time into subclinical and/or overt thyroid disorders 3
The temporal order supports screening for thyroid dysfunction in patients presenting with anxiety disorders 2

Hyperthyroidism precipitates anxiety through direct thyroid hormone effects on brain neurotransmitter systems and widespread activation of peripheral adrenergic receptors, according to the American College of Endocrinology 4
Both overt and subclinical hypothyroidism are associated with increased anxiety symptoms, with thyroid hormone receptors widely expressed in brain areas involved in mood regulation 5

Patients with panic disorder (PD) and social anxiety disorder (SAD) do not differ from healthy controls in resting thyroid parameters (TSH, T3, T4 measured at single time points) 1, 3
Half of studies found evidence for attenuated TSH responses upon stimulation with TRH in patients with anxiety disorders, suggesting subclinical thyroid dysfunction 1, 3
There is a negative relationship between self-reported anxiety levels and TSH levels, meaning higher anxiety correlates with lower TSH 1, 3

Routine screening for thyroid disorders is recommended when treating patients with anxiety disorders, as supported by multiple professional societies 2
Thyroid function testing should be considered in patients presenting with new or worsening anxiety, especially middle-aged patients with mood disturbances or cognitive complaints 5
When evaluating altered mental status with anxiety symptoms, clinicians should consider subclinical hypothyroidism in the differential diagnosis 5
Stress-related long-term alterations in the hypothalamic-pituitary-adrenal (HPA) axis may foster autoimmunity and contribute to shared etiopathogenetic mechanisms between anxiety and thyroid dysfunction 2

Chronic alterations of the hypothalamic‑pituitary‑adrenal (HPA) axis can shift the Th1/Th2 immune balance, thereby increasing the risk of autoimmune thyroid disorders such as Graves’ disease. (Observational evidence) 6
The same mechanistic pathway linking chronic stress to autoimmunity is supported by additional cohort data, reinforcing the potential contribution of stress to thyroid autoimmunity. (Observational evidence) 7

Prospective and retrospective studies document that psychosocial stress frequently precedes the clinical onset of Graves’ disease, although the relationship remains largely circumstantial. (Circumstantial evidence) 8

In individuals with anxiety disorders, higher self‑reported anxiety levels are associated with lower serum TSH concentrations, indicating a tendency toward relative hyperthyroidism rather than hypothyroidism. (Cross‑sectional correlation) 9
Anxiety disorders commonly appear before the development of thyroid disorders; subtle dysregulation of the HPT axis in anxious patients may evolve into subclinical or overt thyroid disease over time. (Longitudinal observation) 10
Approximately 50 % of studies evaluating patients with panic disorder or social anxiety disorder report attenuated TSH responses to TRH stimulation, suggesting mild HPT axis dysfunction but not a pattern consistent with stress‑induced primary hypothyroidism. (Mixed‑study evidence) 11

Routine thyroid function screening is advised for patients receiving treatment for anxiety disorders because of the notable bidirectional comorbidity, reflecting shared pathophysiology rather than a direct causal effect of stress on hypothyroidism. (Expert consensus) 12