EVANSTON, Illinois, Sept. 2 -- Northwestern University issued the following news release: Journal: Proceedings of the National Academy of Sciences (PNAS) EVANSTON, Ill. - While the mental health crisis has touched the lives of young people across a broad age spectrum, new Northwestern University research has found that the presence of difficult social environments and the absence of positive social environments predicted greater increases in depressive symptoms in youth, aged 9-11, over a two- more PR