Psychiatric Technician Practice Exam

Diabetes insipidus is primarily caused by a deficiency in which hormone?

1. Insulin

2. Glucagon

3. Antidiuretic hormone

4. Cortisol

The correct answer is: Antidiuretic hormone

Diabetes insipidus is primarily caused by a deficiency in antidiuretic hormone (ADH), also known as vasopressin. This hormone is produced in the hypothalamus and stored in the posterior pituitary gland. ADH plays a crucial role in regulating the body's water balance by promoting water reabsorption in the kidneys. When there is an insufficient amount of this hormone, the kidneys fail to retain adequate water, leading to excessive urination and dehydration, which are hallmark symptoms of diabetes insipidus. Understanding the role of ADH is essential for recognizing how its deficiency affects fluid balance and the symptoms that arise from such a condition. This distinguishes diabetes insipidus from other types of diabetes, which involve issues with insulin or glucose metabolism rather than water regulation. In contrast, insulin is related to glucose metabolism and its deficiency leads to diabetes mellitus, glucagon primarily works to increase blood glucose levels, and cortisol, which is associated with stress response and metabolism regulation, does not directly relate to fluid balance in the way that ADH does.