The thyroid gland is a small, butterfly-shaped gland located at the base of the neck. It produces thyroid hormones that regulate metabolism, growth, and development. When the thyroid is not functioning properly, it can cause a variety of symptoms – and yes, thyroid problems can definitely mess with your head.
How does the thyroid affect mental health?
The thyroid hormones triiodothyronine (T3) and thyroxine (T4) play a critical role in brain development and function. Thyroid hormones regulate levels of serotonin, norepinephrine, and dopamine – key neurotransmitters that control mood, motivation, memory, and behavior. When thyroid hormone levels are too low (hypothyroidism) or too high (hyperthyroidism), it can alter mood, mental sharpness, and emotional stability.
Hypothyroidism
Common symptoms of hypothyroidism include fatigue, weight gain, feeling cold, dry skin, hair loss, slowed heart rate, constipation, muscle cramps, depression, and problems with memory and concentration.
Many studies have found a strong association between hypothyroidism and psychiatric disorders like depression and anxiety. Researchers believe this is due to the reduction in serotonin and norepinephrine caused by low thyroid hormones.
Around 40-50% of people with hypothyroidism experience depression. Anxiety and panic attacks have also been linked to hypothyroidism. Brain fog, memory lapses, and slowed thinking are common cognitive symptoms.
Hyperthyroidism
Hyperthyroidism can also profoundly impact mental health and cognitive function. Common symptoms include unexplained weight loss, rapid heart rate, intolerance to heat, profuse sweating, muscle weakness, frequent bowel movements, agitation, irritability, and difficulty sleeping.
Thyroid hormone excess has been associated with increased anxiety, nervousness, mood swings, and in severe cases, delirium, hallucinations and mania. Impulsiveness, distractibility, and decreased concentration span are often seen with hyperthyroidism.
Studies indicate that 60% of hyperthyroid patients experience anxiety, while 25-50% experience depression. Bipolar disorder has also been linked to hyperthyroidism.
How are thyroid disorders diagnosed?
Your doctor can test for thyroid disorders with a simple blood test. The most common tests are:
TSH test
Measures levels of thyroid-stimulating hormone (TSH), which is produced by the pituitary gland to stimulate the thyroid. High TSH indicates hypothyroidism, while low TSH indicates hyperthyroidism.
T4 test
Measures circulating thyroxine (T4), which is the main hormone secreted by the thyroid gland. Low T4 indicates hypothyroidism.
T3 test
Measures triiodothyronine (T3), which is converted from T4. Low T3 may indicate hypothyroidism.
Thyroid antibody tests
Measure antibodies that attack the thyroid, which may indicate autoimmune thyroid disorders like Hashimoto’s or Graves’ disease.
If test results are abnormal, your doctor may order additional tests or diagnostic imaging to confirm a thyroid disorder.
What thyroid disorders can affect mental health?
The most common thyroid diseases linked to psychiatric symptoms include:
Hashimoto’s thyroiditis
An autoimmune disorder where the immune system attacks the thyroid gland, causing inflammation and impaired function. Hashimoto’s is the #1 cause of hypothyroidism in the U.S. Patients with Hashimoto’s are at higher risk for developing depression and anxiety.
Graves’ disease
Another autoimmune disorder that causes hyperthyroidism when antibodies overstimulate the thyroid. Graves’ disease has been associated with mood disorders, anxiety, irritability, and cognitive decline.
Postpartum thyroiditis
Caused by inflammation of the thyroid after pregnancy. It can initially lead to hyperthyroidism followed by hypothyroidism. Postpartum thyroiditis has been linked to postpartum depression and anxiety.
Subclinical hypothyroidism
Mild thyroid failure where symptoms are present but lab tests are only slightly abnormal. Subclinical hypothyroidism has been associated with subtle cognitive deficits.
Thyroid hormone resistance
A rare genetic disorder where tissues are unable to respond to thyroid hormones. It is characterized by high levels of circulating thyroid hormones and elevated TSH. Many cases are associated with attention deficit hyperactivity disorder (ADHD).
Who is most at risk?
While thyroid disorders can affect anyone, the following groups have an increased risk of developing thyroid problems:
– Women – especially older women
– People over 60 years old
– Those with a family history of thyroid disease
– Patients with other autoimmune disorders
– Pregnant women or those who recently gave birth
– People with Down syndrome
– Patients with Turner syndrome, which affects X chromosome development
– Individuals who have received thyroid radiation therapy
– People who have had thyroid surgery
Additionally, those with psychiatric disorders like depression, anxiety, and bipolar disease have a higher risk of having an undiagnosed thyroid problem.
How are thyroid disorders treated?
Hypothyroidism is treated with daily oral thyroid hormone replacement medication, such as levothyroxine. Taking supplemental thyroid hormone can help resolve symptoms of fatigue, weight gain, hair loss and depression associated with low thyroid levels.
Hyperthyroidism may be treated with antithyroid medications, radioactive iodine, or surgery to remove the thyroid. Beta blockers help reduce heart rate and tremors from excess thyroid hormone until levels stabilize.
For Hashimoto’s and Graves’ disease, doctors may prescribe corticosteroids or other immunosuppressants to help reduce damaging inflammation and antibodies attacking the thyroid.
With treatment, most of the psychiatric symptoms associated with thyroid disorders improve. However, it’s important to be aware that some mood or cognitive symptoms may persist, especially in long-standing thyroid disease. Bringing thyroid levels back to normal assists with stabilization but additional psychiatric treatment may be warranted in some individuals.
What about subclinical thyroid disorders?
Subclinical hypothyroidism and hyperthyroidism refer to mild forms of low or high thyroid hormone levels that may not initially cause symptoms. In subclinical hypothyroidism, TSH is elevated but T4 and T3 levels remain normal. In subclinical hyperthyroidism, TSH testing shows low levels but thyroid hormones are within normal range.
Research indicates that subclinical thyroid disorders, especially subclinical hypothyroidism, may still contribute to psychiatric symptoms like depression, bipolar disorder and cognitive deficits. One study found that 69% of patients with refractory depression had mild undiagnosed hypothyroidism. Treatment with thyroid hormone improved depression in over one-third of the patients.
Experts recommend screening for thyroid problems in all patients with mood, anxiety, or cognitive symptoms that are difficult to treat. Detecting and addressing subclinical thyroid dysfunction may help resolve psychiatric issues in some cases.
Can you have psychiatric symptoms without thyroid abnormalities?
It’s important to note that not all psychiatric issues are due to an underlying thyroid problem. Many mental health conditions like depression and anxiety have no relation to the thyroid whatsoever. Normal thyroid function tests do not rule out diagnoses such as:
– Major depressive disorder
– Generalized anxiety disorder
– Bipolar disorder
– Schizophrenia
– PTSD
– Personality disorders
Mental illness stems from complex interactions between genetics, brain chemistry, hormones, life events and environmental stressors. They require comprehensive psychiatric assessment and tailored treatment plans.
However, because thyroid disorders are more common in psychiatric patients, checking TSH, T4 and T3 levels can help identify medical causes or contributing factors to mental health symptoms. Addressing thyroid dysfunction is an important part of integrative care.
Takeaways
– Thyroid disorders like hypothyroidism and hyperthyroidism significantly impact mental health.
– Psychiatric symptoms associated with thyroid problems include depression, anxiety, mood swings, irritability, brain fog, memory loss, and concentration problems.
– If thyroid tests are abnormal, mental health often improves with treatment and stabilization of thyroid hormone levels.
– Subclinical thyroid disorders may also contribute to refractory psychiatric symptoms.
– Screening for thyroid abnormalities should be part of the workup for unexplained mental health issues. However, normal tests do not rule out primary psychiatric illnesses which require comprehensive treatment.
– Managing both thyroid and mental health conditions properly is key to optimizing wellness.
Conclusion
Thyroid disorders can most certainly mess with your head, causing a wide range of psychiatric symptoms that can profoundly impact mood, cognition, behavior and quality of life. However, the mind-body connection goes both ways. Mental health problems can also negatively affect thyroid function. The interrelationship between thyroid hormones and mental health is complex.
The good news is that detecting and treating thyroid abnormalities can help resolve certain psychiatric issues or make them more responsive to mental health therapy and medication. While thyroid problems do not account for all psychiatric disorders, they remain an important medical consideration.
In patients with refractory depression, bipolar disorder, anxiety, ADHD or unexplained changes in mood or cognition, checking TSH, T4 and T3 thyroid levels is reasonable to rule out – or identify – a potential thyroid abnormality. Optimizing both thyroid and mental health allows patients to achieve their full wellness potential.