Thyroid function screening in psychiatric in-patients

During a two-year biochemical screening for thyroid disease amongst 191 psychiatric admissions, 38 (20 per cent) had an abnormal result, 5 were hyperthyroid and 7 hypothyroid. Thyroid dysfunction was associated with female sex and affective psychosis, but not with age. During the three weeks before admission the patients with an abnormal result had been prescribed significantly more phenothiazines, antiparkinsonian drugs and lithium than the patients with normal thyroid function. Almost half of those with abnormal function were physically ill on admission. Despite these findings we concluded that in most patients thyroid dysfunction was not a major determinant of the psychiatric disturbance.