Mental health issues are associated with thyroid problems in three key ways. First, people with thyroid disease have higher rates of mental health problems and symptoms. Second, some mental health symptoms are actually the symptoms of an undiagnosed or poorly treated thyroid condition and may resolve fully or in part with proper thyroid treatment. Third, there is evidence that some mental health conditions can be better treated by combining thyroid drugs with traditional antidepressant or antianxiety medications.
Mental health problems in people with thyroid disease
The most common mental health problem in thyroid patients is depression. Research has shown that people with both hypothyroidism and hyperthyroidism are more likely to develop symptoms of depression.
People with thyroid disease show significantly higher rates of a number of other common mental health problems, including:
- Anxiety and panic disorders
- Obsessive-compulsive disorder (OCD)
- Bipolar disorder and cyclothymia
- Post-traumatic stress disorder (PTSD)
Other mental health issues that are seen at higher rates in thyroid patients include:
- Atypical depression
- Borderline personality disorder
There is also a rare form of significant mental illness called myxedema psychosis, or colloquially, “myxedema madness,” caused by severe long-term hypothyroidism. Myxedema madness can be accompanied by extreme agitation, paranoia, psychosis, delusions, hallucinations, aggressiveness, and dementia. Myxedema madness usually resolves over time with aggressive thyroid hormone replacement therapy.
The relationship between thyroid disease and mental health issues is well-known and undisputed. Still, researchers do not have a clear and thorough understanding of why thyroid patients have an increased incidence of these mental health issues.
Depression (also known as major depressive disorder) is a condition that affects mood, thinking, and can cause physical symptoms. The symptoms range from mild to severe, and include:
- Feelings of sadness
- Feelings of emptiness
- Difficulty concentrating, memory problems
- Feeling overwhelmed
- Difficulty sleeping or sleeping too much
- Loss of interest in activities or hobbies
- Low sex drive or loss of interest in sex
- Overeating or a loss of appetite
- Body and muscle aches and pains
- Chronic headaches
- Stomach and digestive problems
- Thoughts of suicide
Depression is the most common mental health issue facing thyroid patients and is considered a symptom of both hypothyroidism and hyperthyroidism. Depression is actually so common in people with thyroid conditions that the prescribing instructions for all antidepressants recommend that your physician evaluates your thyroid function to rule out any thyroid abnormality before prescribing antidepressant drugs. The American Association of Clinical Endocrinologists supports this approach, saying: "The diagnosis of subclinical or clinical hypothyroidism must be considered in every patient with depression.” Unfortunately, thyroid screening prior to prescribing antidepressant drugs is rarely done by most general practitioners and primary care physicians.
Depression is frequently seen in people with hyperthyroidism. Researchers have found that depressive disorders occur in up to 70 percent of hyperthyroid patients.
Depression is also common in hypothyroidism. Interestingly, research shows that as much as 40 percent of people suffering from depression actually have subclinical or overt hypothyroidism that is not treated.
Hypothyroidism is also a factor in refractory depression, defined as depression that does not respond to treatment with at least two antidepressant drugs. More than half of all patients with refractory depression have evidence of untreated hypothyroidism.
At the same time, since the 1960s, a number of studies have demonstrated that the addition of thyroid hormone appears to accelerate and enhance the clinical response to antidepressant drugs. As a result, some psychiatrists prescribe thyroid hormone replacement medication — in some cases levothyroxine, and more commonly the synthetic T3 thyroid drug liothyronine (Cytomel) — along with traditional antidepressant drug therapy for refractory depression.
The diagnostic and treatment challenge for some patients and practitioners is in determining if the symptoms are evidence of depression or hypothyroidism — or both conditions. Harvard’s Health Letter outlined the shared symptoms, and the symptoms unique to depression, and to hypothyroidism:
- Shared symptoms: depressed mood, fatigue, weight gain, reduced sex drive, difficulty concentrating
- More typical of depression: insomnia, feelings of guilt, suicidality, feelings of worthlessness
- More typical of hypothyroidism: feeling cold, constipation, dry skin and hair, hair loss, reduced heart rate or blood pressure, neck and eye changes
Anxiety disorder, also known as generalized anxiety disorder (GAD) is a condition where you experience ongoing and longer-term anxiety or worry. The symptoms of anxiety disorder include:
- Chronic worrying
- Difficulty concentrating
- Feeling jumpy and irritable
- Pounding and rapid heartbeat, heart palpitations
- Stomach pain or nausea
- Shortness of breath
- Muscle tension, spasms, or twitches
- Tremors, shaking, trembling
Panic disorder is a type of anxiety disorder that includes repeated periods of intense anxiety, as well as feelings of dread, fear, and doom accompanied by intense physical symptoms of anxiety.
Anxiety and panic disorders and symptoms are seen in both hypothyroidism and hyperthyroidism. In one research study of women psychiatric patients with a lifetime history of panic disorder:
- 27 percent had a history of thyroid disorder
- 17 percent had hypothyroidism
- 8 percent had hyperthyroidism
According to research, anxiety disorders have been found to occur in approximately 60 percent of hyperthyroid patients.
Again, proper thyroid diagnosis and treatment will, in some cases, improve or even fully resolve anxiety and panic symptoms.
What should you do?
If you are experiencing depression and considering antidepressant therapy, or have depression that is not responding to drug treatment, it’s important to have a thorough evaluation — including a clinical thyroid examination, and thyroid stimulating hormone (TSH), free T4, free T3, and thyroid antibody tests — to rule out an underlying thyroid problem. Similarly, if you are experiencing anxiety or panic disorder, you should have a clinical examination and a full panel of thyroid tests to rule out an underlying thyroid problem.
If your doctor discovers that you do have a thyroid condition, optimal thyroid treatment may resolve your mental health issues partially or fully without medication. Or, if you are already being treated with an antidepressant or anti-anxiety medication, optimal thyroid treatment may make it possible for your doctor to reduce your dosage of — or even eliminate — your medication.