But sometimes the situation is reversed – a physical illness is mistaken for a psychiatric one due to overlapping symptoms.
One excellent example occurs in the presence of thyroid disease. Whether an individual has too little thyroid hormone (called hypothyroidism) or too much (called hyperthyroidism), psychiatric symptoms are often present.
Unfortunately, since other symptoms of a thyroid condition might not be as easily noticed, many cases of thyroid disease remain incorrectly diagnosed.
The thyroid is a small gland at the base of the neck. Its job is to take iodine from the blood and produce two hormones that regulate the energy use of many cells and organs throughout the body. When this gland isn’t working properly, physical and mental symptoms can occur.
Women are four times more likely than men to develop thyroid problems.
It is much more common to have an underactive thyroid gland than an overactive gland.
Most commonly, hypothyroidism (the underactive gland) is caused by an immune disorder called Hashimoto disease.
Also, more than five per cent of women develop at least temporary hypothyroidism after giving birth.
Hypothyroidism causes the body to seem as though it is running in slow motion. Symptoms could include fatigue, diminished concentration and memory, weight gain or feeling cold.
Depression can also result from hypothyroidism. In fact, some research suggests that up to 20 per cent of all chronic depression cases could be the result of hypothyroidism.
Another face of thyroid disease is hyperthyroidism (or an overactive gland). Common symptoms found when the thyroid gland is producing too much hormone include rapid heartbeat, nervousness, irritability, muscle weakness and feeling hot. Family members also often report a change in personality and increased moodiness. All of these symptoms frequently lead to a diagnosis of an anxiety disorder or panic attacks.
Both hypothyroidism and hyperthyroidism can also cause psychotic symptoms such as delusions and hallucinations.
The commonalities between depression, anxiety and hypothyroidism are not surprising. The most active form of the thyroid hormone, triiodothyronine (T3), is a neurotransmitter that helps to regulate serotonin and norepinephrine, which are known to be involved in several psychiatric conditions including mood and anxiety disorders.
In fact, T3 is sometimes used in conjunction with antidepressants when treating individuals who don’t have a thyroid problem but aren’t responding fully to standard medication.
Treatment for thyroid-induced psychiatric symptoms can include hormone therapy to balance thyroid levels. Antidepressant medications may also be useful in dealing directly with mood and anxiety symptoms.
Most importantly, if you are experiencing symptoms of depression or anxiety, speak with your doctor and ask to have your thyroid levels tested.
Dr. Paul Latimer is president of Okanagan Clinical Trials and a Kelowna psychiatrist.