The laboratory assessment of thyroid function with special reference to the importance of thyroid abnormality in psychiatric disease

Abstract

The aims of this study were to investigate the incidence and clinical importance of thyroid abnormalities in an acute psychiatric population and to use such information in the development of a laboratory diagnostic policy for the investigation of such groups. This involved the use of established in vitro assays for serum thyroxine (T+), triiodothyronine uptake (T3U), triiodothyronine (13) and thyroidstimulating hormone (TSH) , together with the development and evaluation of both thyroxine binding globulin (TBG) and thyroxine binding prealbumin (TBPA) assays. For comparison, both the Wickham Survey (Tunbridge et al.,1977) and data obtained from general medical and surgical patients, were used as reference. The analytical study revealed that TBG measurement offered no advantage over TU in the routine assessment of thyroid function, but was only of value in cases where the T3U was greater than 135-140%. However TBPA measurement was shown not to have any role in the evaluation of thyroid status, despite several theoretical advantages over both T3U and TBG...