Levothyroxine-Associated Anxiety and Depression

Introduction to Levothyroxine Therapy

• The American College of Physicians, as reported in the Annals of Internal Medicine, recommends optimizing levothyroxine dosing to minimize the risk of anxiety and other adverse effects, as approximately one-quarter of patients receiving levothyroxine are inadvertently maintained on doses high enough to make TSH levels undetectable 1

Monitoring and Treatment Approach

• The American College of Physicians, as reported in the Annals of Internal Medicine, suggests that monitoring both psychiatric symptoms and thyroid parameters together is crucial, as mood symptoms may reflect subtle HPT axis dysfunction even when baseline thyroid levels appear normal 1
• The guideline recommends administering the minimum dose of levothyroxine that achieves the desired clinical and biochemical response, to minimize the risk of anxiety and other adverse effects 1

Considerations for Formulation Change

• Change levothyroxine formulation when TSH levels are suppressed (undetectable) indicating overdosage, which directly causes anxiety symptoms through excessive thyroid hormone 1

Adjunctive Therapy

• Triiodothyronine (T3) has been successfully used as augmentation therapy in depressed patients resistant to first-line antidepressants, as reported in Praxis Medical Insights 3