Re: How do you know for sure?
There is no blood test, psychological test, x-ray, or other definitive means of "diagnosing" an individual as a malignant narcissist. As with most personality disorders (those disorders that are LEARNED and not organic in origin), it's mainly a process of elimination and/or affirmation. I'm pasting a number of "symptoms" below and including a couple of sites that might help.
It is important to understand that we all experience some degree of narcissism - we want to be recognized, appreciated, soothed, etc. Malignant narcissism is when an individual's choices of behavior deliberately harm other human beings for the sake of the nacissist's pleasure and/or entertainment. As Molly pointed out, don't equate narcissism with a perpetrator of abuse, though one can share the behaviors of the other. Some people are just jerks, and that's all there is to it. Others are very deliberate and scheming in their choices of behaviors.
Best wishes to you.
From the Mayo Clinic Site:
http://mayoclinic.com/health/narcissistic-personality-disorder/DS00652/DSECTI...
"Screening and diagnosis
Narcissistic personality disorder is diagnosed based on signs and symptoms, as well as a thorough psychological evaluation. Your doctor or mental health provider will ask you to describe the signs and symptoms you're experiencing — what they are, when they occur, how intense they are and how long they last, for example. You also might discuss how your life is affected or limited by your symptoms. And you may be asked to fill out psychological evaluations or questionnaires.
Although there's no laboratory test to diagnose narcissistic personality disorder, you may also have a physical exam to make sure you don't have a physical problem causing your symptoms.
Some features of narcissistic personality disorder are similar to those of other personality disorders. Your mental health provider will take care to make sure you get the proper diagnosis. It's possible to be diagnosed with more than one personality disorder at the same time.
To be diagnosed with narcissistic personality disorder, you must meet criteria spelled out in the Diagnostic and Statistical Manual of Mental Disorders (DSM). This manual is published by the American Psychiatric Association and is used by mental health providers to diagnose mental conditions and by insurance companies to reimburse for treatment.
Criteria for narcissistic personality disorder to be diagnosed include:
Having an exaggerated sense of self-importance
Being preoccupied with fantasies about success, power or beauty
Believing that you are special and can associate only with equally special people
Requiring constant admiration
Having a sense of entitlement
Taking advantage of others
Inability to recognize needs and feelings of others
Being envious of others
Behaving in an arrogant or haughty manner "
Other sites include:
http://www.samvak.tripod.com
http://www.narcissism.operationdoubles.com
http://www.narcissism101.com
(opinion-based information)
http://www.halcyon.com