What is the difference between manic depressive narcissism and borderline personality disorder?

First of all, Manic Depression is now referred to as Bi-Polar Disorder and it is a mood disorder. Narcissism (Narcissistic Personality Disorder) and Borderline Personality Disorder are that, Personality Disorders. Someone diagnosed as manic depressive narcissism sounds like a dual disorder, one disorder 'confounded' by another. Since manic depression is bi polar disorder there is a dis-regulation in the highs (mania) and lows (depression). Some people self medicate by using alcohol (a depressant) when they are too high, and using cocaine for example (a stimulant) when they are too low. It is the body's attempt to find a stable mood. Both alcohol and stimulants can exacerbate the signs and symptoms of Narcissistic Personality Disorder. The 'Narcissistic rage' ignited or inflamed by alcohol is one example. NPD tend to be angry, nasty, exploitive, explosive, evasive, demanding. They are extremely difficult to get along with or live with. NPD have a fear of abandonment, real or imaginary, can not manage emotions in adult fashion, and will initiate break up, take no responsibility for outcome and bask in victim-hood.
Borderline Personality Disorder also shows signs of distress around abandonment, real or imaginary, and can not regulate emotions. BPD also rage when they are afraid, fearful or insecure, which only serves to push people away. "Mommy Dearest" is a good portrayal of BPD.
There is a spectrum of axis II personality disorders often overlapping. Plenty of info on line.
Barbara Kennedy MPH/MSW