Dr. Hope developed a new method for treating depression. He decided to work with a hospital to test the effectiveness of his method. He identified a group of 40 depressive patients in the hospital and randomly assigned them to be treated with a placebo drug or his new "talk therapy" method. In weekly sessions, Dr. Doom was told to administer the placebo and Dr. Hope administered his new "talk therapy". After eight weeks, each Doctor reported on the number and intensity of depressive symptoms in their patients. Data showed that patients in the placebo group showed more and more intense depressive symptoms than those in the "talk therapy" group. Dr. Hope advertised his results on the internet and enlisted numerous new patients to undergo treatment with his "talk therapy" treatment.

1. Identify the independent variable(s).

2. Identify the dependent variable(s).

3. Identify any confounding variable(s).

4. Propose a method to "unconfound" the experiment