 This can occur during pregnancy, obesity, cold adaptation, stay in high altitudes, endurance exercise, acute psychosis, and PTSD.According to newer theories elevated concentrations of TSH and thyroid hormones in type 2 allostasis result from an up-regulated set point of the feedback loop, which ensues from increased TRH expression in the basolateral amygdala and the paraventricular nucleus of the hypothalamus in response to stress.High-T3 syndrome in thyroid carcinoma may result from autonomous thyroid hormone secretion or overexpression of type 2 deiodinase in cancer cells rather than from type 2 allostasis.