Here's how I see it:
The passage basically lays out a chain reaction:
* Things like depression, anxiety, and drug use can mess with your deep sleep.
* Deep sleep is critical because it's when your body is supposed to "reset" the mechanism that makes you sensitive to pain (the one involving substance P).
* If you don't get that deep sleep, the reset doesn't happen.
* The passage then says that if this mechanism can't be reset, it can run wild and cause fibromyalgia.
So, if you connect those dots, the conditions listed in step 1 (depression, anxiety, etc.) can directly lead to the outcome in step 4 (fibromyalgia) by blocking the necessary reset. This is why (D) makes the most sense. Those conditions can cause it by starting this whole chain reaction, or they could aggravate an existing case by continuously preventing the reset that would offer relief.
Why the other options are incorrect:
(A) The passage describes a mechanism, not a treatment. It never discusses the "simplest way to treat" the condition.
(B) This statement is too strong. The passage says the conditions "can interfere" with deep sleep, not that they always interfere to the point that the mechanism "cannot be reset".
(C) This is also too strong ("will not"). The passage lists some conditions that can interfere with sleep, but it doesn't say they are the only things that can. It's also possible for fibromyalgia to have other causes not mentioned in the text.
(E) This reverses the logic and makes a probability claim ("most likely") that the text doesn't support. The passage says drug use can be a factor in causing fibromyalgia, not that people with drug use and pain most likely have it (their symptoms could be from many other causes).
souvik101990
Neuropeptide substance P 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 stages of deep sleep. If, however, the mechanism cannot be reset, this process may run out of control and cause fibromyalgia, a disorder characterized by body-wide chronic pain and fatigue. Conditions such as depression, anxiety, drug use, and serotonin deficiency can interfere with stages of "deep" sleep.
The statements above, if true, best support which of the following conclusions?
(A) The simplest way to treat fibromyalgia is to control the release of neuropeptide substance P.
(B) The release of neuropeptide substance P cannot be reset if a patient suffers from a condition that interferes with stages of "deep" sleep.
(C) Patients who do not suffer from conditions that can interfere with stages of "deep" sleep will not develop fibromyalgia.
(D) Conditions such as depression, anxiety, drug use and serotonin deficiency can aggravate or even cause fibromyalgia.
(E) Drug users who experience body-wide chronic pain and fatigue most likely suffer from fibromyalgia.