What is the relationship between mood swings and thyroid disorders, specifically hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid)?

From the Guidelines

Mood swings in patients with hypothyroidism and hyperthyroidism can be effectively managed by normalizing thyroid hormone levels, with hypothyroidism typically requiring levothyroxine treatment and hyperthyroidism often necessitating methimazole, propranolol, or other interventions 1.

Treatment Approaches

• Hypothyroidism is usually treated with levothyroxine, starting at a dose of 25-50 mcg daily and adjusted every 6-8 weeks based on TSH levels 1.
• Hyperthyroidism may require methimazole (10-30 mg daily), propranolol for symptom control (10-40 mg, 3-4 times daily), or in some cases radioactive iodine or surgery 1.

Managing Mood Symptoms

• Mood symptoms, such as depression, anxiety, and irritability, often improve as thyroid function normalizes, although this may take several weeks 1.
• During the adjustment period, adequate sleep, stress management techniques, and regular exercise can help manage mood fluctuations.
• If severe mood symptoms persist despite normalized thyroid levels, additional psychiatric evaluation may be necessary, as thyroid disorders can sometimes unmask underlying mood disorders 1.

Importance of Thyroid Function Testing

• Thyroid function tests are recommended in all patients presenting with mood symptoms, as hypothyroidism and hyperthyroidism can coexist with various underlying conditions 1.
• Early diagnosis and treatment of thyroid disorders can significantly improve mood symptoms and overall quality of life 1.

From the Research

Mood Swings and Thyroid Disorders

• Mood swings are a common symptom associated with thyroid disorders, including hypothyroidism and hyperthyroidism 2.
• Thyroid hormones play a crucial role in regulating mood, and an imbalance of these hormones can lead to mood disorders 2.
• Studies have shown that patients with hypothyroidism or hyperthyroidism are more likely to experience mood swings and other psychiatric symptoms 2, 3.

Hypothyroidism and Mood Swings

• Hypothyroidism is a condition where the thyroid gland does not produce enough thyroid hormones, leading to a range of symptoms including mood swings 4.
• Treatment of hypothyroidism with levothyroxine (LT4) replacement therapy can help alleviate mood swings and other symptoms 4.
• However, it is essential to monitor thyroid-stimulating hormone (TSH) levels to ensure that the treatment is effective and not causing any adverse effects 5.

Hyperthyroidism and Mood Swings

• Hyperthyroidism is a condition where the thyroid gland produces excess thyroid hormones, leading to a range of symptoms including mood swings 6.
• Treatment of hyperthyroidism depends on the underlying cause and may involve antithyroid medications, radioactive iodine ablation, or surgical thyroidectomy 6.
• It is crucial to monitor TSH levels and adjust treatment accordingly to prevent hypothyroidism and other complications 5.

Relationship between Thyroid Hormones and Mood Disorders

• Thyroid hormones exert their action in the central nervous system through various mechanisms, including modulation of gene expression and influence on serotonin and noradrenergic neurotransmission 2.
• The relationship between psychiatric drugs, deiodinases, and thyroid hormones is complex and can help understand the mechanisms of action of these drugs 2.
• Selective serotonin reuptake inhibitors (SSRIs) can affect thyroid function, particularly in patients with normal thyroid function, and may lead to changes in T3 and T4 levels 3.