Thyroid Disorders and Diseases

• Asymptomatic, non-pregnant, adults over the age of 18, with no prior history of thyroid disorders are recommended to not have routine screening for thyroid dysfunction.^[1] Generally speaking, if a patient has depressive symptoms or cognitive dysfunction, then they are not asymptomatic.
• Females with hypothyroidism are the most susceptible to depression, while the association of depression with other thyroid conditions is less than previously thought.^[2]

Treatment of subclinical hypothyroidism in adults with depression has been shown to improve depressive symptoms.^[3]

• Clinician Reviews: Is that thyroid nodule malignant?
• Clinician Reviews: Thyroid Nodules

Thyroid peroxidase antibody (TPO) is elevated in 20% of women with postpartum psychosis, compared to 5-7% of all postpartum women.^[4] There is an association between postpartum thyroid dysfunction and depression. In some cases, TSH should be ordered in women with a history of goitre, type I diabetes, prior postpartum depression, thyroid disease history (including prior low free T4 level), a family history of thyroid disease, or a personal history of smoking. If the TSH level is abnormal, a free T4 should also be ordered.^[5]

Screening for thyroid dysfunction is a part of the work up for cognitive impairment and dementias.