Thyroid Dysfunction and Mental Health

At the base of your neck is a small, butterfly-shaped gland called the thyroid. For most people, the thyroid rarely comes to mind, unless something goes wrong. When your thyroid dysregulates, the most noticeable effects are often physical symptoms like fatigue and weight changes. However, thyroid dysfunction can also affect your mood, your thoughts, your sense of self, and your emotional world.

If you have a thyroid disorder, it is likely to contribute to additional difficulties, such as depression or anxiety. At the very least, the thyroid issues you’re experiencing can significantly worsen your mood symptoms. Understanding this connection could be the missing piece in getting the right diagnosis and the right care. This article will explore:

• The connection between thyroid dysfunction, endocrine disorders, and mental health.
• How thyroid imbalance causes mood swings and mental health challenges.
• When thyroid testing for mental health concerns is warranted.
• Treatment for thyroid-related depression and other mood disorders.

The Connection Between Thyroid Dysfunction and Mental Health

Thyroid hormones influence everything from reproductive health to energy levels to body temperature regulation.^[1][2] But thyroid hormones also play an important part in your mental health, and thyroid dysfunction is a common endocrine contributor to psychiatric symptoms.

This relationship has been recognized in medical research for over a century. The science dates back to 1888 when doctors first associated severe psychiatric symptoms with untreated hypothyroidism (which later became known as “myxedema madness”). This condition involved an array of symptoms, including:^[3][4][5]

• Hallucinations.
• Paranoia.
• Acute psychosis.

The relationship between thyroid dysfunction and mental health isn’t a one-way street. Thyroid dysfunction can trigger mental health symptoms, and mental health conditions can alter thyroid functionality. Because of this bidirectional relationship, it is important to understand how thyroid function and mental health interact.^[6]

How Thyroid Hormones Affect the Brain

Two primary hormones produced by the thyroid gland are T3 and T4. The more prevalent of the two is T4, which is tasked with storage and transport and is relatively inactive on its own. Your body converts T4 into T3, the active form of the hormone, which then enters your body’s cells and does its work.^[5]

The majority of T3 in the brain is produced via this process, which is regulated by enzymes called deiodinases. Nowhere is this conversion more important than in the brain, where T3 directly influences processes related to:^[4][5]

• Mood.
• Metabolism.
• Brain function.
• Heart rate.

Its relationship with mood comes from its regulatory power over serotonin and noradrenaline (the very same neurotransmitters targeted by antidepressants). Therefore, when T3 is low, you may develop symptoms of anxiety or depression.^[1][5]

The Hypothalamic-Pituitary-Thyroid Axis and Mood

T3 and T4 don’t work in isolation, though. Their production is part of a feedback loop called the hypothalamic-pituitary-thyroid axis (HPA axis), which is the communication system your brain uses to control thyroid hormone production. When that loop is disrupted, as can happen with illness, thyroid disease, or stress, your mood and overall mental health can suffer.^[4]

HPT axis disruptions are frequently noted in both depression and anxiety, and stress can also blunt the HPT axis’s work. The result is a cycle where thyroid dysfunction worsens mood symptoms, and mood symptoms worsen thyroid function.^[3][4]

Hyperthyroidism and Mental Health

While hypothyroidism slows everything down, hyperthyroidism has the opposite effect. As a result, hyperthyroidism mental health symptoms are distinct, but can be equally disruptive.^[1][3] In this case, anxiety is the primary psychiatric symptom, occurring in up to 80 percent of patients. Anxiety-related symptoms like irritability, emotional lability, nervousness, and restlessness are common.^[3][10] Thyroid imbalance and mood swings are particularly pronounced in hyperthyroidism, with emotions often shifting rapidly and unpredictably.

Other common mental health symptoms of thyroid disease include:^[3][10]

• Depression, especially long-term cases, occurs in up to 70 percent of people with hyperthyroidism.
• Graves’ disease, which is the most common cause of hyperthyroidism, also has an association with depression, anxiety, and, less commonly, mania and psychosis.
• Psychosocial stress is linked to the onset and relapse of Graves’ disease.
• Apathetic hyperthyroidism sometimes occurs in older adults. Rather than the classic anxiety symptoms, people with this condition often present as depressed and lethargic, with mental slowing.

These conditions are treatable, and symptoms often improve once thyroid function returns to normal. However, some symptoms can continue for some time after successful treatment.^[10]

When to Test Thyroid Function for Mental Health Concerns

Given how closely thyroid symptoms mimic depression, anxiety, and even bipolar disorder, knowing when to test for thyroid dysfunction is a crucial part of getting the right diagnosis.1,^[3] The American Association of Clinical Endocrinologists recommends that anyone presenting with depression be screened for thyroid dysregulation.^[3][4]

Thyroid testing typically involves a panel of blood tests to assess thyroid function. These tests look at TSH, T3, T4, and various antibodies, and give doctors a much more complete picture of thyroid functioning than a single test targeting just one of the elements listed above.^[1][4]

Numerous signs warrant a conversation with your doctor or mental health provider about thyroid testing. These may include, but are not limited to:^[3][4][9]

• Unexplained fatigue.
• Cognitive complaints with no clear cause.
• Treatment-resistant depression.
• Mood symptoms that don’t respond to standard psychiatric treatment.

It is also important to recognise that, due to the bidirectional relationship between thyroid dysfunction and mood disorders, diagnosis and treatment should be handled by both endocrinologists and mental health professionals.^[6]

Treatment Options for Thyroid-Related Mood Disorders

Treating thyroid-related depression and other mood disorders starts with addressing the underlying thyroid condition. By normalizing your thyroid hormone levels, you should see significant improvements in your mood symptoms.^[3][4][10]

Thyroid hormone therapy is a common option for this. T3 is used to accelerate the response to antidepressants, particularly in treatment-resistant depression. Even if you don’t have an overt thyroid dysfunction, T3 can help minimize your mood symptoms.^[11]

Your doctor might prescribe you an SSRI (selective serotonin reuptake inhibitor) to regulate serotonin levels. But since SSRIs and thyroid hormones appear to work on the same neural pathways, combining T3 with SSRIs can be particularly effective.^[11]

It is important to understand that SSRIs are not specifically designed to treat thyroid-related depression. Instead, they’re a broad antidepressant used for many different forms of depression, which, in this case, is used as a supporting intervention alongside treating the thyroid condition first.^[3][4]

The thyroid medication and mood relationship can be further enhanced with changes to your daily routine. Prioritizing sleep, eating a healthy diet, getting regular exercise, and reducing stress will individually and collectively help manage thyroid-related mood symptoms.^[11]

When Thyroid Treatment Isn’t Enough

If you’re among the many people whose mood symptoms continue even after your thyroid levels have normalized, an integrated mental health care approach is essential. In addition to the interventions discussed above, treatment for thyroid-related depression and other mood disorders should include psychotherapy or cognitive rehabilitation.^[4][9]

Thyroid-related mood disorders can affect:

• How you think about yourself.
• How you feel.
• How you view your future.

Your beliefs and expectations about your condition and how it affects your life can directly shape your emotional experience with it. Psychotherapy, especially cognitive behavioral therapy (CBT), can help you identify and reframe these unhelpful thought patterns, develop effective coping strategies, and manage the emotional burden that accompanies thyroid dysfunction.^[10][9]

Cognitive rehabilitation can be an effective treatment if you have memory problems, executive functioning difficulties, or brain fog. This treatment offers structured, practical strategies to improve your daily functioning, including:^[9]

• Memory compensation.
• Organizational strategies.
• Attention training.

The aim is essentially to train your brain to work around its deficits.^[9]

Find Treatment for Thyroid-Related Depression and Mental Health Challenges

Navigating the overlap between thyroid dysfunction and mental health is rarely straightforward, and it isn’t something you should have to figure out on your own. Mission Connection offers compassionate, evidence-based care to help you navigate the complexities of your mental and physical health.

We customize your outpatient treatment program to fit your needs and accept most major insurances. With locations in California, Virginia, and Washington, options include in-person programming, telehealth, or a hybrid approach.

If that sounds like something that could help support you, reaching out to a mental health professional is a worthwhile step. Call 866-833-1822 for a free, no obligation conversation.