Thyroid Research Thyroid Research Archive Thyroid Disease

Small abnormalities in thyroid function are not associated with anxiety, depression, or cognitive dysfunction

(November 2006)

The background of the study. Patients with small increases or decreases in thyroid function may have mood disorders or cognitive dysfunction. In this study, the frequency of anxiety, depression, and cognitive dysfunction was determined in a large group of normal subjects and subjects with subclinical and overt thyroid dysfunction.

How the study was done. The study subjects were 5857 women and men aged 65 years or older attending general practices in England. Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale and cognitive function was assessed using the Folstein Mini–Mental State Examination (MMSE) and the Middlesex Elderly Assessment of Mental State (MEAMS) test. Serum thyrotropin (TSH) and free thyroxine (T4) were measured at the same time.

The results of the study. Fifteen subjects (0.2 percent) had overt hyperthyroidism (low serum TSH, high free T4), 127 (2.2 percent) had subclinical hyperthyroidism (low serum TSH), 5524 (94.3 percent) were normal, 168 (2.9 percent) had subclinical hypothyroidism (high serum TSH), and 23 (0.4 percent) had overt hypothyroidism (high serum TSH and low free T4). The anxiety score was > or = to8 in 370 subjects (6.3 percent) and the depression score was > or = to8 in 136 (2.3 percent).

The score for anxiety was lower in the subjects with overt hyperthyroidism than in those with subclinical hyperthyroidism or the normal subjects, but there were no differences in the scores for anxiety in the subjects with overt hypothyroidism or subclinical hypothyroidism and the normal subjects. The score for depression also was lower in the subjects with overt hyperthyroidism than in the normal subjects, but it was higher in the subjects with subclinical hyperthyroidism. There were no differences in the scores for depression in the subjects with overt hypothyroidism or subclinical hypothyroidism and the normal subjects. The scores on the tests of cognitive function were similar in all the groups.

The conclusions of the study. The frequency of anxiety, depression, and cognitive dysfunction are not increased in older subjects with either overt or subclinical thyroid dysfunction, as compared with normal subjects.

The original article. Roberts LM, Pattison H, Roalfe A, Franklyn J, Wilson S, Hobbs FD, Parle JV. Is subclinical thyroid dysfunction in the elderly associated with depression or cognitive dysfunction? Ann Intern Med 2006;145:573-81.