V02-32

Official Solution:


Scientists have several rival theories on the causes of fibromyalgia, a disorder that causes body-wide chronic pain and fatigue. One leading theory holds that conditions such as depression, anxiety, drug use and serotonin deficiency can aggravate or even cause fibromyalgia by interfering with "stage 4," or "deep sleep." This theory is concerned with the function of neuropeptide substance P, which is released in the spinal cord in response to pain and causes nerve endings around the initiating nerves to also become more sensitive to pain. Normally, this mechanism is "reset" during deep sleep. If pain becomes body-wide, however, and the mechanism can not be reset, this process may run out of control. Therefore deep sleep plays a vital role in preventing fibromyalgia.

The theory above on the cause of fibromyalgia rests on which of the following assumptions?


A. The body has a limited amount of control over neuropeptide substance P.
B. Fibromyalgia can be treated by strong sedative medication.
C. In order to have “stage 4” sleep, a person must not have anxiety.
D. The functions of neuropeptides released by the spinal cord must be better understood before a cure for fibromyalgia can be found.
E. Because the causes of fibromyalgia are linked to depression, the disorder should be treated by mental health professionals.


Premise: Deep sleep resets a mechanism that controls the release of neuropeptide substance P. Uncontrolled release of the substance causes fibromyalgia.

Conclusion: Deep sleep plays an essential role in preventing fibromyalgia.

The key is to recognize that this reset is necessary because the body does not have unlimited control over the substance P.

A. CORRECT. If the body had unlimited control on substance P, then deep sleep would not be required to reset the mechanism of releasing P, and thus the argument would be invalid.

B. Out of scope. This option does not bridge the premise with conclusion. It states an alternative method of treating fibromyalgia, but does not bear on the role of deep sleep on the fibromyalgia.

C. This option is a conclusion from the following part in the passage: One leading theory holds that conditions such as depression, anxiety, drug use and serotonin deficiency can aggravate or even cause fibromyalgia by interfering with "stage 4," or "deep sleep." This part implies anxiety causes lack of deep sleep and hence in order to have deep sleep, a person must not have anxiety. However this option does not link the premise to the conclusion of the passage and hence is not an assumption.

D. Out of scope. The passage is concerned with the causes of fibromyalgia, not its cures.

E. The passage lists several conditions that can aggravate or cause fibromyalgia, but does not prioritize depression as the condition most linked to its onset.


Answer: A