Many people are unaware that problems with the thyroid gland can affect their mental health.
A person experiencing persistent sadness, tiredness, and poor concentration may believe they are suffering from depression. Another person who feels anxious, restless, irritable, and unable to sleep may think they have an anxiety disorder.
However, in some cases, an underlying thyroid problem may cause or worsen these symptoms.
The thyroid is a small, butterfly-shaped gland located in the front of the neck. It produces hormones that regulate several important bodily functions, including energy production, metabolism, body temperature, and heart rate.
Thyroid hormones also play an important role in normal brain function.
When the thyroid produces too little or too much hormone, it can affect a person’s mood, thinking, memory, sleep, and behavior.
Understanding this connection is important because thyroid disorders can sometimes resemble psychiatric illnesses or make existing mental health problems worse.
The thyroid produces two main hormones: thyroxine (T4) and triiodothyronine (T3).
These hormones influence brain function, including processes involved in emotional regulation, concentration, and memory.
There are two major types of thyroid dysfunction:
Hypothyroidism (underactive thyroid): The thyroid does not produce enough thyroid hormones. This can slow down physical and mental processes.
Hyperthyroidism (overactive thyroid): The thyroid produces too much thyroid hormone. This can speed up bodily functions and cause physical and psychological overactivity.
Both conditions may produce symptoms that resemble psychiatric disorders.
Yes. Hypothyroidism can cause symptoms similar to depression and may contribute to depressive symptoms in some individuals.
When thyroid hormone levels are too low, many bodily functions slow down. The brain may also slow down, affecting mood, thinking, and energy levels.
Common psychological symptoms include:
Persistent sadness or low mood
Loss of interest in previously enjoyable activities
Constant tiredness and lack of motivation
Difficulty concentrating
Forgetfulness and poor memory
Slowed thinking and difficulty making decisions
Excessive sleepiness
Irritability or anxiety
These symptoms can closely resemble depression.
For example, a previously active person may gradually become withdrawn, tired, and uninterested in daily activities. Although depression may initially be suspected, blood investigations could reveal an underactive thyroid.
Certain physical symptoms may provide additional clues:
Unexplained weight gain
Increased sensitivity to cold
Dry skin and hair loss
Constipation
Facial puffiness
Menstrual irregularities
A slow heart rate
The combination of psychological and physical symptoms may prompt a doctor to investigate thyroid function.
In rare cases, severe untreated hypothyroidism can cause marked confusion, hallucinations, or delusions.
Yes. Excessive thyroid hormone levels can produce symptoms that closely resemble anxiety disorders.
An overactive thyroid increases the body’s metabolic activity and can cause persistent physical and mental overactivity.
Common psychological symptoms include:
Excessive anxiety or nervousness
Restlessness and difficulty relaxing
Irritability and impatience
Difficulty sleeping
Emotional instability or frequent mood changes
Difficulty concentrating
Feeling constantly tense or overwhelmed
Occasionally, symptoms resembling panic attacks
Some people may experience racing thoughts, increased activity, or unusually elevated mood.
Rarely, severe hyperthyroidism may produce symptoms resembling mania or psychosis.
Physical symptoms may include:
Rapid heartbeat or palpitations
Excessive sweating
Increased sensitivity to heat
Trembling of the hands
Unexplained weight loss despite a normal or increased appetite
Frequent bowel movements
Muscle weakness
For example, someone experiencing palpitations, trembling, sweating, and intense nervousness may initially believe they have a panic disorder.
However, thyroid tests may identify hyperthyroidism as a key contributing factor.
Yes. Thyroid dysfunction may complicate the course or treatment of certain psychiatric conditions.
Depression
An underactive thyroid can contribute to depressive symptoms and should be considered when evaluating depression, particularly when fatigue, cognitive slowing, or other physical symptoms are present.
If someone is not improving adequately with depression treatment, clinicians may reassess possible contributing medical conditions, including thyroid dysfunction.
However, not everyone with depression has a thyroid problem, and mildly abnormal thyroid test results do not necessarily explain depressive symptoms.
Bipolar Disorder
Thyroid abnormalities may influence mood symptoms in people with bipolar disorder.
There is another important connection: lithium, a medication commonly used to treat bipolar disorder, can sometimes cause hypothyroidism.
For this reason, thyroid function should be checked before starting lithium and monitored regularly during treatment.
If hypothyroidism develops, it can often be treated with thyroid hormone replacement without necessarily stopping lithium. Treating doctors should make the decision.
Anxiety Disorders
Hyperthyroidism may cause anxiety-like symptoms or worsen anxiety in someone who already has an anxiety disorder.
Identifying and treating the thyroid problem may help reduce these symptoms.
Hashimoto’s thyroiditis is an autoimmune disorder in which the immune system attacks the thyroid gland.
Over time, it can lead to hypothyroidism and associated symptoms such as tiredness, low mood, poor concentration, and memory difficulties.
A rare and complex neurological condition historically called Hashimoto’s encephalopathy has also been described in association with thyroid antibodies. It may involve confusion, seizures, behavioral changes, or other neurological and psychiatric symptoms.
However, thyroid antibodies alone do not establish this diagnosis. Such symptoms require careful neurological assessment to exclude other possible causes.
Because thyroid disorders can resemble psychiatric illnesses, thyroid testing may be an important part of a mental health assessment.
A doctor may particularly consider thyroid investigations when:
Depression or anxiety develops without an obvious explanation.
Psychological symptoms occur alongside unexplained weight changes, palpitations, fatigue, or temperature intolerance.
Unusual changes in mood, behavior, or concentration occur.
Psychiatric symptoms have not improved as expected with treatment.
The person has a history of thyroid disease or autoimmune disorders.
The person is taking medications that can affect thyroid function, particularly lithium.
Thyroid tests may also be relevant when children or adolescents develop unexplained changes in behavior, school performance, or growth.
The main blood tests include:
1. Thyroid-Stimulating Hormone (TSH)
TSH is usually the first test used to assess thyroid function. An abnormal result may suggest an underactive or overactive thyroid.
2. Free T4 (Thyroxine)
This test measures one of the main thyroid hormones and helps determine the nature and severity of thyroid dysfunction.
3. Free T3 (Triiodothyronine)
This test may be useful when hyperthyroidism is suspected, particularly when other results require further clarification.
4. Thyroid Antibodies
Additional blood tests may be recommended when an autoimmune thyroid disorder, such as Hashimoto’s thyroiditis or Graves’ disease, is suspected.
Not everyone needs all these tests. The doctor selects the appropriate investigations based on the patient’s symptoms, medical history, and initial results.
Treatment depends on whether the thyroid is underactive or overactive.
Treatment of Hypothyroidism
Hypothyroidism is generally treated with levothyroxine, a medication that replaces the thyroid hormone the body is unable to produce adequately.
As thyroid hormone levels return to normal, associated symptoms such as fatigue, poor concentration, and low mood may improve.
However, improvement may take several weeks or longer, and not all psychiatric symptoms necessarily disappear after thyroid treatment.
If a person also has depression or another psychiatric disorder, separate mental health treatment may still be necessary.
Treatment of Hyperthyroidism
Treatment may include:
Medications that reduce thyroid hormone production
Beta-blockers to temporarily relieve symptoms such as palpitations and trembling
Radioactive iodine treatment in selected cases
Surgery when appropriate
As thyroid function improves, associated symptoms of nervousness, irritability, and sleep disturbance often improve as well.
However, persistent anxiety or other psychiatric symptoms may require additional assessment and treatment.
In certain patients with depression that has not responded adequately to conventional treatment, psychiatrists may consider adding a thyroid hormone called liothyronine (T3) to antidepressant medication.
This is a specialist treatment option and is not routinely recommended for everyone with depression.
It requires careful medical supervision because excessive thyroid hormone can cause palpitations, anxiety, irregular heart rhythms, and other complications.
Not necessarily.
If the psychiatric symptoms are mainly caused by thyroid dysfunction, correcting the thyroid abnormality may lead to substantial improvement.
However, some people have both a thyroid disorder and an independent psychiatric illness.
For example, someone with hypothyroidism may also have major depressive disorder. In such cases, treating the thyroid condition alone may not be sufficient.
The person may need appropriate psychiatric treatment, including psychotherapy, medication, or both.
This is why a comprehensive assessment is important rather than assuming that every psychological symptom is caused by thyroid disease.
Consider consulting a healthcare professional if you experience persistent depression, excessive anxiety, unexplained mood changes, poor concentration, or significant sleep disturbances.
A professional assessment is particularly important if these symptoms are accompanied by changes in weight, heart rate, body temperature tolerance, or energy levels.
Sudden severe confusion, marked behavioral changes, or hallucinations require urgent medical assessment, particularly when accompanied by significant physical symptoms.
An underactive thyroid can produce symptoms resembling depression, while an overactive thyroid can produce symptoms resembling anxiety. Thyroid dysfunction may also complicate existing psychiatric conditions.
Fortunately, thyroid disorders can often be identified through relatively simple blood tests and treated effectively.
The important message is that persistent changes in mood, behavior, or thinking should not automatically be attributed to either a psychiatric illness or a thyroid disorder without an appropriate assessment.
Recognizing the possible relationship between physical and mental health allows clinicians to make more accurate diagnoses and provide appropriate treatment.
Seeking Professional Help
If you have concerns about your mental health or that of someone you care about, seeking professional guidance can be an important first step. A professional assessment can help clarify the nature of the difficulties and identify appropriate treatment or support.
To enquire about an appointment at Al Soor Specialist Clinic LLC, Sharjah, or to learn more about our services, please contact us at +971 6 551 2913.
Disclaimer: This article is intended for general information and education only. It is not a substitute for professional assessment, diagnosis, or individualized treatment advice.
