Depression occurs most frequently in women aged 25 to 44.
Women experience depression at roughly twice the rate of men.
Research shows a definite connection between hypothyroidism and depression, and it has been well established that depression is a symptom of low thyroid function. People with depression, anxiety and psychiatric problems often have low levels of thyroid hormone.
Hypothyroidism is a condition in which your thyroid gland doesn’t produce enough thyroid hormone or thyroid hormone isn’t being used efficiently at the cellular level. Subclinical hypothyroidism is defined as low thyroid function that goes undiagnosed because it is below the surface of clinical detection, or has no recognizable clinical findings. Subclinical hypothyroidism is defined as a condition without typical symptoms of hypothyroidism, elevated TSH, and normal circulating thyroid hormone.
People with hypothyroidism may experience any or all of the following symptoms, but will often be misdiagnosed because of a single blood test: constant tiredness, difficulty losing weight, constipation, coarse hair, dry skin, cold intolerance, muscle cramps, memory loss, irritability, and abnormal menstrual cycles. Thyroid hormone governs our body’s metabolism and energy production. Without adequate levels of thyroid hormone and its proper utilization, symptoms such as depression, anxiety, mood swings, brain fog and poor concentration become increasingly prevalent.
The Relationship Between Hypothyroidism and Depression
Patients with thyroid disorders are more prone to develop depressive symptoms. Today, it is well recognized that disturbances in thyroid function may significantly affect mental status including emotion and cognition. Both excess and insufficient thyroid hormones can cause mood abnormalities, including depression, that is generally reversible with adequate thyroid treatment. Furthermore, thyroid hormones are reported by many to be an effective treatment for depression. Primary thyroid disorders including both hypothyroidism and hyperthyroidism may be accompanied by various neuropsychiatric manifestations ranging from mild depression and anxiety to overt psychosis. (1)
According to the American Association of Clinical Endocrinologists, “The diagnosis of subclinical or clinical hypothyroidism must be considered in every patient with depression”. Among the various neuropsychiatric manifestations of thyroid disorders, depression remains the most common. (1)
Researchers studied the lifetime history of major depression in 16 subjects with subclinical hypothyroidism and 15 subjects whose thyroid function was completely normal. The lifetime frequency of depression was significantly higher in the subjects who met the criteria for subclinical hypothyroidism (56%) than in those who did not (20%), suggesting that subclinical hypothyroidism may lower the threshold for the occurrence of depression. (2)
The prevalence of depressive symptoms based on Beck’s Scale among subclinical hypothyroidism patients was about 2.3 times higher than those with normal thyroid function. Results showed a significant association of subclinical hypothyroidism with psychiatric disorders and an increased frequency of depression and anxiety symptoms in subclinical hypothyroidism in relation to the group without hypothyroidism. (3)
Findings suggest that suboptimal thyroid function increases vulnerability to the occurrence of depression and represents a risk factor for depression in females. (4) An elevated level of thyroid peroxidase antibodies, as found in autoimmune thyroiditis, was significantly associated with depression. It was concluded that women with autoimmune thyroiditis are especially vulnerable to depression. (7)
“You aren’t depressed because you have low levels of Prozac in your blood.”
-Dr. Steven Hotze
Dangers of Antidepressants
Unfortunately, it is common for people with hypothyroidism to be given a misdiagnosis of a psychiatric illness, such as depression. Often a person’s TSH blood work is “within the normal range,” so their physician will determine they are not hypothyroid strictly based on this one lab value, and diagnose them with depression. Unfortunately, this diagnosis often leads to the prescription of antidepressants. We strongly caution against the use of antidepressants. These drugs are dangerous because they are addictive and have many negative side effects, including more depression, and homicidal and suicidal tendencies. Dr. Peter Breggin, an expert witness on antidepressants and how they affect your brain, testifies at trials on how these drugs affect behavior that leads to murder and suicide.
In 2004, the Food and Drug Administration (FDA) issued a black-box warning on antidepressants indicating that they were associated with an increased risk of suicidal thinking, feeling, and behavior in young people. (5) The FDA conducted a series of meta-analyses of 372 randomized clinical trials of antidepressants involving nearly 100,000 participants, which showed that the rate of suicidal thinking or suicidal behavior was 4% among patients assigned to receive an antidepressant, as compared with 2% among those assigned to receive placebo. (6)
If you are currently taking an antidepressant, please do not stop – you must work with your doctor to wean off of it slowly and safely. A great resource is “The Antidepressant Solution: A Step-by-Step Guide to Safely Overcoming Antidepressant Withdrawal, Dependence, and ‘Addiction” by Dr. Joseph Glenmullen.
Effective Treatment of Depression with Desiccated Thyroid (T3 and T4)
In our practice, our physicians have had great success in treating the symptoms of hypothyroidism with desiccated thyroid, which has both T3 and T4, the active and inactive thyroid hormones. We find that most patients on Synthroid (T4 only) don’t get a resolution of their symptoms.
In patients treated with T4, psychological symptoms may persist even when they achieve a normal thyroid state. This study is the first evidence to indicate that patients on thyroxine (T4 only) replacement even with a normal TSH display significant impairment in psychological well-being compared to controls of similar age and sex. (1, 8) It is important to note in one study that therapy with levothyroxine (T4) alone was not sufficient to induce a total remission of depressive symptoms. (1)
One research study compared the effects of thyroxine (T4) alone with those of thyroxine (T4) plus triiodothyronine (T3) in 33 patients with hypothyroidism. Among 17 scores on tests of cognitive performance and assessments of mood, 6 were better or closer to normal after treatment with thyroxine plus triiodothyronine. Similarly, among 15 visual-analogue scales used to indicate mood and physical status, the results for 10 were significantly better after treatment with thyroxine plus triiodothyronine. In patients with hypothyroidism, partial substitution of triiodothyronine (T3) for thyroxine may improve mood and neuropsychological function; this finding suggests a specific effect of the triiodothyronine normally secreted by the thyroid gland. (9)
Remember, the root cause of depression does not lie in an antidepressant deficiency. Treating depression lies in treating the underlying cause, which often occurs with a decline in your thyroid function.
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1. The Link Between Thyroid Function and Depression