Psychological and cognitive disturbances, including unexplained irritability, anxiety, depression, and memory problems, may be under-recognized symptoms of hypothyroidism, a condition affecting nearly five percent of Americans ages 12 and older. Experts are calling for increased consideration of thyroid tests in patients experiencing these symptoms.
Jim Harwood, 73, a computer programmer, described experiencing intense anger over trivial matters, a stark contrast to his usual demeanor. He also struggled with focus and concentration, finding it difficult to keep his mind on his work or remember names. Initially, he considered possibilities ranging from dementia to other serious neurological conditions, never suspecting his thyroid was the cause.
"It just wasn't something I suspected," Harwood stated.
Kristien Boelaert, professor of endocrinology at the University of Birmingham and a trustee of the British Thyroid Foundation, emphasized that hypothyroidism often goes undiagnosed. "If people go to their doctor with anxiety or depression – especially if they are showing any of the other more commonly recognized physical symptoms – then doctors should be prepared to suggest tests for thyroid function," she advised.
The thyroid gland, a small butterfly-shaped organ in the neck, produces hormones essential for bodily functions. In hypothyroidism, insufficient hormone levels can lead to physical symptoms such as fatigue, weight gain, feeling cold, constipation, dry or thinning hair, muscle weakness, and aches. However, due to the presence of thyroid hormone receptors in the brain, the condition can also manifest as psychological and cognitive issues.
"It's not as widely recognized, but if levels of thyroid hormones are low it can cause psychological issues. A lot of people can suffer these symptoms for a long time without realizing they're suffering from a thyroid disorder," said Lyn Mynott, chief executive of the nonprofit Thyroid UK.
Hypothyroidism is more prevalent in women and becomes more common with age, particularly after 60. Mynott noted that thyroid-related psychological issues are frequently misdiagnosed, especially in middle-aged women who may attribute their symptoms to stress or, if older, to the onset of dementia. When these patients seek help, doctors may overlook thyroid dysfunction and opt for treatments like antidepressants or stress reduction advice, which do not address the root cause if hypothyroidism is present.
Undiagnosed hypothyroidism can lead to serious health problems. Slowed heart rate and elevated cholesterol levels increase the risk of cardiovascular issues. For women, it can also disrupt ovulation, affect menstrual cycles, and cause fertility problems.
In rare, severe cases, untreated hypothyroidism can result in myxedema coma, a life-threatening condition where bodily functions slow to dangerously low levels.
Harwood's own diagnosis came only after he developed a range of physical symptoms, including a 20-pound weight gain, persistent cold intolerance, and debilitating fatigue. He also developed a goiter, an enlarged thyroid gland. After being prescribed synthetic thyroid hormone medication, his symptoms, including the psychological ones, largely disappeared.
"Once I started on the medication, my mood completely lifted," he said. "It was really something. I just wish it hadn't taken so long."
