An abbreviation used to covertly refer to Manic Depressive Disorder (Bipolar) or Major Depressive Disorder (Unipolar). Simply referring to it as M.D.D. helps avoid random strangers eavesdropping and thinking you’re nuts.
My M.D.D. is playing up again. That’s why you haven’t seen much of me recently.
by The Captive Spirit August 24, 2010