A health psychologist in a northern climate wants to evaluate the claim that UV lamps help lower depressive symptoms in middle-aged women. She recruits volunteers who meet the criteria for clinical depression and assigns them to two groups: one group receives a standard treatment for depression and undergoes a half hour of UV lamp therapy each day; the other group receives the same standard treatment for depression but without UV lamp therapy. At the end of two months, she administers a depression inventory where lower scores indicate fewer depressive symptoms (lower levels of depression). Assume all other variables are controlled for in the study. Evaluate the claim that depression treatment plus the UV lamp results in lower depression scores than depression treatment alone.
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Depression Treatment + UV
|
Depression
Treatment Only
|
|
34
29
43
31
29
25
12
|
14
31
17
22
19
27
32
|
39
29
13
41
26
23
47
|
31
25
14
24
37
41
42
|