Question: A researcher studies the effect of a drug (MAO inhibitor) on the number of nightmares occurring in veterans with post-traumatic stress disorder (PTSD). A sample of PTSD clients records each incident of a nightmare for 1 month before treatment. Participants are then given the medication for 1 month, and they continue to report each occurrence of a nightmare. For the following hypothetical data, determine whether the MAO inhibitor significantly reduces nightmares. Use the .05 level of significance and a one-tailed test.

Number of Nightmares

One month before treatment One month during treatment
6 1
10 2
3 0
5 5
7 2