A Psychiatrist Is Testing a Drug That Treats Depression

Multiple Choice

A psychiatrist is testing a drug that treats depression. He has given the drug to all his patients, and all of them have experienced a decrease in depressive symptoms. Although this is interesting, his experience is limited because he does not have:

A) a reliable way to` measure depressive symptoms.
B) a comparison group that did not receive the drug.
C) a hypothesis.
D) psychotherapy to supplement the drug.