The real mental illnesses: Susan Nolen-Hoeksema (1959-2013) in memoriam.

Susan Nolen-Hoeksema's life work concerned rumination, gender differences in depression, and the "transdiagnostic" processes in mental illness. The articles in this special section expand on these themes. Her work on transdiagnostic processes leads us to consider that the real mental illnesses are not the congeries of symptoms in the Diagnostic and Statistical Manual of Mental Disorders, but these processes themselves.