The results of research led by Hans Breiter, MD, professor of Psychiatry and Behavioral Sciences at Northwestern University Feinberg School of Medicine and a psychiatrist at Northwestern Memorial Hospital, was recently published in the Journal of Neuroscience. Lead author Jodi Gilman, a researcher in the Massachusetts General Center for Addiction Medicine and an instructor in Psychology at Harvard Medical School, indicated this is the first study to show that the casual use of marijuana is related to major brain changes in two areas: the nucleus accumbens and the amygdala. Both these regions play a major role in emotion and motivation. Co-senior study author Anne Blood, director of the Mood and Motor Control Laboratory at Massachusetts General and assistant professor of psychiatry at Harvard Medical School, said that these brain areas form the basis for how you assess positive and negative features about things in the environment and make decisions about them. Part 2 tomorrow.