If a person has a low TSH level with regards to their thyroid function, they usually do not have problems with depression because it is a high TSH level that contributes to depression in people, according to Harvard University. A low TSH level means that a person has hyperthyroidism and that there are too many thyroid hormones being produced in the person's body.
The excess production of the thyroid hormone has many symptoms such as breathing problems, anxiety problems, moody feelings, nervousness, fatigue, feelings of being too hot, warm and itchy skin, weight loss, thinning hair and an excess of bowel movements, according to WebMD. Doctors are able to diagnosis the condition of hypothyroidism by running a blood test that examines TSH levels. For people who have a high level of TSH, the condition is hypothyroidism instead where depression is a potential side effect.
For people with lower levels of TSH, the diagnosis is not automatically hyperthyroidism though it is the most common according to the National Institutes of Health's MedlinePlus. People with lower levels of TSH may have toxic nodular goiter, an excess of iodine in their body or Graves' disease. There are also some medications that are prescribed by doctors and lead to a lower level of TSH hormone production such as chemotherapy drugs, dopamine and opioid painkillers.