Final answer:
The disorder with the highest mortality rate among all psychological illnesses is D. anorexia nervosa.
Step-by-step explanation:
Anorexia nervosa is an eating disorder characterized by a severe restriction of calorie intake, an intense fear of gaining weight, and a distorted body image. It can lead to significant physical complications, including organ damage, heart problems, and even death.
Research has shown that the mortality rate for anorexia nervosa is higher than that of any other mental illness. According to a study, the mortality rate for anorexia nervosa is estimated to be around 5-10%, with cardiac arrest being the leading cause of death. This high mortality rate emphasizes the seriousness of anorexia nervosa and the importance of early intervention and treatment.
It is important to note that while other psychological illnesses such as depression, schizophrenia, and bipolar disorder can also have severe consequences, anorexia nervosa stands out as having the highest mortality rate among them. Therefore the correct answer is D. anorexia nervosa.