Baking for winter holidays is a tradition that may have a sound medical basis. In midwinter, when days are short, man...

Ravi August 11, 2019

@Silvia,

Happy to help. Let's look at (A), (C), (D), and (E).

(A) says, "Seasonal depression is one of the most easily treated forms
of depression."

The problem with (A) is that the passage never states that seasonal
depression is easy to treat, let alone the easiest form of depression
to treat. Thus, (A) is out.

(B) says, "Lack of sunlight lowers the level of serotonin in the brain."

This is a very tricky answer choice. Technically though, serotonin
only comes up as a possible way to improve one's mood. Some
antidepressants act by raising serotonin levels, but that doesn't
necessarily mean that lowered serotonin levels cause depression. For
example, one way to lose weight is to have weight loss surgery. That
doesn't mean that a weight gain is caused by a lack of weight loss
surgery, though. It's possible that these remedies help address the
symptoms (depression as mentioned in the stimulus and weight gain in
our example here) without addressing the root causes of these
problems. Thus, (B) is out.

(C) says, "People are more likely to be depressed in midwinter than at
other times of the year."

It's pretty reasonable to infer from the stimulus that people are more
likely to be seasonally depressed in midwinter. However, that doesn't
mean that they're more likely to be all kinds of depressed in
midwinter. It's possible that other types of depression are less
common in the winter than they are during other times of the year, so
we can get rid of (C).

(D) says, "Some antidepressants act by changing the brain's level of serotonin."

The stimulus tells us that the cookies have the same effect as some
antidepressants. Since the cookies act by changing the brain's
serotonin levels, that means some depressants act the same way. Thus,
(D) is the correct answer choice, as it's something we can infer from
the passage.

(E) says, "Raising the level of neurotransmitters in the brain
effectively relieves depression."

The problem with (E) is that it's too general to be true. Raising
serotonin relieves depression, and serotonin is one type of
neurotransmitter. That doesn't mean that raising the level of
neurotransmitters in general has the same effect. Thus, (E) is out.

Does this make sense? Let us know if you have any other questions!

Ravi August 11, 2019

@Silvia, I also explained (B), so you can see the breakdown of each answer choice.