Thyroid mood swings
Pro Research Analysisby 
Searched over 200M research papers
Thyroid Function and Mood Swings: A Comprehensive Overview
Introduction to Thyroid and Mood Disorders
Thyroid function plays a crucial role in regulating mood and emotional well-being. Research has consistently shown that both hyperthyroidism and hypothyroidism can lead to significant mood disturbances, including depression and anxiety5 8. This article synthesizes findings from multiple studies to explore the intricate relationship between thyroid function and mood swings.
Postpartum Mood Disturbances and Thyroid Function
Postpartum Blues and Thyroid Hormones
Postpartum mood disturbances, such as postpartum blues, are prevalent among new mothers. A study conducted on Greek women found that lower levels of serum Free T3 (FT3) and Free T4 (FT4) within the normal range were associated with higher scores of postpartum blues in the first week after delivery1. Specifically, women with lower FT3 and FT4 levels experienced more severe mood disturbances, indicating a negative correlation between these thyroid hormones and postpartum mood swings1.
Thyroid Hormones and Mood Disorders
Thyroid Hormone Therapy in Depression
Thyroid hormones have been used to treat mood disorders, particularly depression and bipolar disorder. Triiodothyronine (T3) has been shown to accelerate the antidepressant response to tricyclic antidepressants and augment the therapeutic response in patients with refractory depression3 9. Additionally, supraphysiologic doses of levothyroxine (LT4) have demonstrated efficacy in improving depressive symptoms and stabilizing mood in patients with rapid cycling and refractory bipolar disorder3 9.
Subclinical Thyroid Disorders and Mood
Subclinical thyroid disorders, which are often overlooked, can also impact mood. Symptoms such as fatigue, mood swings, and cognitive changes commonly seen during menopause can reflect underlying thyroid dysfunction4. Even within the normal reference range, variations in thyroid hormone levels can influence psychological well-being. For instance, higher FT4 levels within the normal range have been associated with poorer cognitive outcomes and mood disturbances8 10.
Seasonal and Circannual Patterns
Seasonal Variation in Thyroid Function and Mood
Seasonal changes can affect thyroid function and mood. A study on individuals residing in Antarctica found that both thyroid-stimulating hormone (TSH) and mood exhibited a circannual pattern, with peaks in certain months and troughs in others. Declines in FT3 and FT4 levels were associated with increased tension, anxiety, and overall mood disturbances, suggesting a feedback loop between mood and thyroid hormone levels7.
Mechanisms of Thyroid Influence on Mood
Neurotransmitter Modulation
Thyroid hormones are believed to modulate mood by influencing neurotransmitter systems, particularly serotonin and norepinephrine. This modulation can help explain the mood-stabilizing effects of thyroid hormone therapy in mood disorders6 9. The identification of nuclear T3 receptors and the expression of deiodinase isoenzymes in the brain further support the role of thyroid hormones in mood regulation9.
Conclusion
The relationship between thyroid function and mood swings is complex and multifaceted. Lower levels of thyroid hormones, even within the normal range, can lead to significant mood disturbances, particularly in postpartum women and individuals with subclinical thyroid disorders. Thyroid hormone therapy has shown promise in treating mood disorders, highlighting the critical interplay between endocrine and neural systems. Future research is needed to further elucidate these mechanisms and optimize treatment strategies for mood disorders associated with thyroid dysfunction.
Sources and full results
Most relevant research papers on this topic
Thyroid function and postpartum mood disturbances in Greek women.
Lower levels of serum FT3 and FT4 within normal limits are associated with an increased incidence of mood disturbances in the first postpartum week.
Observational Study
Rigorous JournalMood disorders and the thyroid axis
Thyroid hormone metabolism may influence mood disorders, and thyrotropin-releasing hormone may play a role in antidepressant and mood stabilizer treatments.
Role of thyroid hormone therapy in depressive disorders
Thyroid hormone therapy can effectively modulate mood disorders and improve clinical outcomes when combined with psychotropic medications.
Systematic ReviewRigorous JournalSubclinical thyroid disorders.
Subclinical thyroid disorders, often mistaken for overt thyroid disorders, can cause symptoms in midlife women, and their diagnosis and management require a multidisciplinary approach.
Rigorous JournalThyroid Hormone Use in Mood Disorders: Revisiting the Evidence.
Thyroid hormone therapy (THT) shows potential benefits and harms in managing unipolar and bipolar depression, with benefits mainly related to serotonin and norepinephrine modulation.
Literature ReviewCircannual pattern of hypothalamic–pituitary–thyroid (HPT) function and mood during extended antarctic residence
Winter-over syndrome symptoms are linked to relative CNS hypothyroidism, with seasonal variations in thyroid function and mood affecting individuals during extended antarctic residence.
Observational StudyThyroid hormone: Influences on mood and cognition in adults.
Thyroid hormones influence mood and cognition in adults, with subclinical hyperthyroidism and higher free thyroxine levels within the normal range linked to poorer cognitive outcomes.
Literature Review
Highly CitedThyroid Hormone, Neural Tissue and Mood Modulation
Thyroid hormones can modulate mood and behavior in affective disorders, potentially enhancing the therapeutic response to antidepressants and stabilizing long-term illness in bipolar and unipolar patients.
Highly CitedPsychological well-being correlates with free thyroxine but not free 3,5,3'-triiodothyronine levels in patients on thyroid hormone replacement.
Psychological well-being correlates with free thyroxine and TSH levels in treated hypothyroid patients, but not with symptoms typical of anxiety or depression.
RCT
Large Human Trial
Very Rigorous JournalHighly Cited