RESEARCH STUDY 1.2: Dr. White reads about a new theory that states that depression is caused by increased levels of estrogen in the womb. To test this theory, she conducted a study comparing the level of estrogen in amniotic fluid in individuals who were later diagnosed with depression with the level of those who did not develop depression. Dr. White found no differences between the groups in estrogen levels in the amniotic fluid. In this study, "depressed individuals will have higher estrogen levels" was the .