[Thyrotoxicosis in the very old, a changed disease picture]

The diversity of symptoms arising from thyreotoxicosis was investigated by means of the Wayne and New Castle diagnostic indices in 13 psychiatric and 14 mentally healthy old people as well as in 14 young people, all of whom clearly suffered from hyperthyroidism, according to the appropriate radiochemical indicators. Due to the absence of the usual ophthalmological and adrenergic symptomatology, the Wayne index (normal over 20) was found to be insufficient among all the old people (the mean scores for the two groups were 9.0 and 17.9 respectively). The New Castle index (normal over 40) showed a low normal value in the case of 12 of the 14 mentally healthy old people, and was too low in the mentally disturbed old people (averages 41.5 and 29). Certain typical characteristics were nonetheless observable within the limits of the psychiatric picture. For the present the mechanism of this shift in symptoms remains unexplained. The shift may theoretically have connections with the sharply reduced TRH concentration, or, more reasonably, with the decreased reactivity of adrenergic receptors in the elderly. Whether this explanation also suits for the findings in the psychiatric ill is far from certain. In cases of psychiatric or somatic problems of an undefined nature among very old people it would seem to be advisable to check the functioning of the thyroid in order to avoid the risk of missing the correct diagnosis, especially that of a reversible organic psychosyndrome.