What condition results from oversecretion of ACTH?

The oversecretion of ACTH, or adrenocorticotropic hormone, leads to a condition known as Cushing's disease. This condition is characterized by excessive production of cortisol from the adrenal glands due to prolonged stimulation by ACTH. In Cushing's disease, the pituitary gland produces too much ACTH, which in turn causes the adrenal glands to increase cortisol production. The symptoms of Cushing's disease can include weight gain, thinning skin, high blood pressure, and other significant metabolic alterations, reflecting the effects of chronic excess cortisol in the body.

In contrast, Addison's disease is associated with insufficient levels of cortisol due to damage to the adrenal glands, not an oversecretion of ACTH. Myxedema refers to severe hypothyroidism resulting from a lack of thyroid hormone rather than an issue with ACTH. Pheochromocytoma is a tumor of the adrenal gland that leads to excess production of catecholamines (like epinephrine and norepinephrine), not ACTH. Therefore, the link between ACTH oversecretion and Cushing's disease clearly distinguishes it as the correct answer in this context.