Are Low Basal Serum Levels of the Thyroid Stimulating Hormone (b-TSH) a Risk Factor for Switches into States of Expansive Syndromes (Known in Germany as „Maniform Syndromes” in Bipolar I Depression?

Switching over from depression into states known an "maniform" in Germany ("expansive syndromes") been frequently, observed and appears to be partially related to the type of antidepressive medication. Apart from the medication, some evidence suggests that additional factors such as thyroid function may be relevant for the switchover. With this background, the aim of the present study was to evaluate the hypothesis that depressed bipolar patients with lower basal TSH serum levels (b-TSH) on admission at the hospital as inpatients are at a higher risk of switching from depression into "maniform" states than depressed bipolar patients with higher b-TSH. From a total of 158 bipolar depressed patients, 16 patients developed mania during their hospital stay. After dividing the sample of patients at the median b-TSH into one group with lower b-TSH (N = 78) and another group with higher b-TSH (N = 79), we found that the switchover rate to mania was significantly higher in the group of patients with lower b-TSH (15.4%) than in the group of patients with higher b-TSH (5.1 %). These findings suggest that lower b-TSH may be a risk factor for switching over from depression into "maniform" states in bipolar depressed patients.