People with major depressive disorder are much more likely to have imm

Typical GMAT Cause and Effect Assumption ques..

Cause:- depressive disorder
Effect:- immune disorders

correct ans to these type of problems are mostly in 3 forms:
"Effect doesn't cause the Cause..."
"Cause happens before the Effect.."
"No Alternative reason for Effect..."

Correct ans D. Immune disorders do not cause major depressive disorders in many people
correct ans is the form of "Effect doesn't cause the Cause..."

sananoor

This is a typical GMAT logic structure. The following generalization may help solve this type of problems:

General Structure: A and B are observed to happen together. Conclusion - A causes B
assumption: B does NOT cause A !!

Here,
A = major depressive disorders
B = immune disorders
Conclusion: A causes B, i.e. major depressive disorders cause immune disorders.
Assumption: B does not cause A, i.e. immune disorders do not cause major depressive disorders.

People with major depressive disorder are much more likely to have immune disorders such as lupus and chronic fatigue syndrome than people who are not depressed.
This suggests strongly that major depressive disorder reduces the body’s ability to fight infection,
because primary infections are thought to cause many of these immune disorders.

This argument indicates that depressions result in infections which cause immune disorders.

This is causal argument.

Which of the following is an assumption required by the argument above?

A. People who are depressed do not tend to overstate the severity of their symptoms........whether they state or overstate does not affect the likelihood of having a disorder.

B. People with major depressive disorder are less careful than others about protecting themselves from infection................out of scope.

C. Major depressive disorder does not usually have a very sudden onset.................out of concern

D. Immune disorders do not cause major depressive disorders in many people...............This is one of the 3 assumptions that define causal argument. Negation of this statement collapses the argument.

E. Many immune disorders are known to have causes other than primary infections...............out of scope.

In assumption question one has to choose an answer choice that strengthen the conclusion but above argument contains few facts...
Depressive Disorder-----Causes---> Immune Disorders(such as lupus and chronic fatigue)
Depressive disorder----also reduces the body ability to fight infections which in return causes immune disorders So he cycle is

1) depressive disorder causes-->infections--->infection causes immune disorder
one has to strengthen this cause and effect cycle and only way is by saying that
its not Immune Disorder that---causes----depressive disorder
Its D
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This is exellent.!! Where could i get more tips like these - really struggling with CR questions..

This problem contains a classic flaw relating to correlation and causation. While there is evidence that major depressive disorder is strongly correlated with certain immune disorders, there is no evidence that one is causing the other. Maybe it is the case that immune disorders are causing the depression, not the other way around!

In order to make this conclusion, you need to know that immune disorders are not the cause of the depression and answer choice (D) does this perfectly. Assumption-negation is a helpful technique for dealing with the negatively worded answer choices (A), (C) and (D) – read them affirmatively to see if they weaken the argument.

For (A), if depressed people DO tend to overstate the severity of their symptoms, then it is not a problem in this argument so (A) is not correct.

In (C) if depression DOES usually have a sudden onset, then it is also not a problem for this argument, so (C) is not correct.

For (D), if immune disorders DO cause many cases of depression, then the whole argument falls apart and you have the correct answer.

(B) is tricky but if people with depression are less careful than others about protecting themselves from depression then it WEAKENS this argument as it gives another possible explanation for the conclusion.

(E) is relatively easy to eliminate as other causes would not be important in this argument.
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OFFICIAL SOLUTION


D. This problem contains a classic flaw relating to correlation and causation. While there is evidence that major depressive disorder is strongly correlated with certain immune disorders, there is no evidence that one is causing the other. Maybe it is the case that immune disorders are causing the depression, not the other way around! In order to make this conclusion, you need to know that immune disorders are not the cause of the depression and answer choice (D) does this perfectly. Assumption-negation is a helpful technique for dealing with the negatively worded answer choices (A), (C) and (D) – read them affirmatively to see if they weaken the argument. For (A), if depressed people DO tend to overstate the severity of their symptoms, then it is not a problem in this argument so (A) is not correct. In (C) if depression DOES usually have a sudden onset, then it is also not a problem for this argument, so (C) is not correct. For (D), if immune disorders DO cause many cases of depression, then the whole argument falls apart and you have the correct answer. (B) is tricky but if people with depression are less careful than others about protecting themselves from depression then it WEAKENS this argument as it gives another possible explanation for the conclusion. (E) is relatively easy to eliminate as other causes would not be important in this argument.

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