According to Wikipedia (http://en.wikipedia.org/wiki/Megalomania):
“Megalomania is a psychopathological condition characterized by delusional fantasies of power, relevance, omnipotence, and by inflated self-esteem.[1] Historically it was used as an old name for narcissistic personality disorder prior to the latter’s first use by Heinz Kohut in 1968, and is used today as a non-clinical equivalent.[2][3] It is not mentioned in the Diagnostic and Statistical Manual of Mental Disorders (DSM)[4] or the International Statistical Classification of Diseases (ICD).”

Megalomania and narcissism are virtually interchangeable. However, they have slightly different connotations. Narcissism involves a preoccupation with–and some say excessive–love of one’s self. Megalomania implies a more successful, money-hungry definition of narcissism. While narcissists often have delusions of grandeur, megalomaniacs always do. It may seem like splitting hairs to make a distinction between the two, and since either of these often escape diagnosis, it probably really doesn’t matter which term we use. Suffice it to say: megalomania is another word for narcissism.
The definition of mental illness is an actual medical condition that negatively affects a person’s feelings, mood, ability to relate to others, and day-to-day functioning. Narcissism (or narcissistic personality disorder (NPD)) or megalomania can both be described this way. Mental illness definition is not necessarily useful when dealing with NPD or megalomania, as 1.) Most narcissists do not go to a therapist so will therefore not be diagnosed. And, 2.) a person with NPD will most likely not seek help and will deny that they have a problem.

So, what do you do when you are dating or married to a megalomaniac? If you are dating a megalomaniac, my advice would be to seriously think about whether you want to try to fight a battle that you can’t win. Unless you have major ties, such as a child together, I’d seriously consider being tied to this person for life. Research the disorder as much as you can. Read the rest of my blog. While it is sad to see a loved one in pain, and they’ll likely experience pain when you leave them, ultimately, it is not fair to you or your future family to put them in a position of vulnerability with the megalomaniac. I’ve been in your shoes. There are many other men/women out there that also deserve love that will give you a healthy relationship. With the internet, it is easy to find others to date. I, myself, met my future husband on the internet quickly. I only looked for a few months. Invest your time in someone who is healthy. It sounds selfish, but you are choosing a father/mother for your future family. It IS a big deal! A divorce and custody battle is horrendous. It is the hardest, most gut-wrenching thing I’ve ever been through and it is SO hard on your children. Trust me! You DON’T want to do this! Read stories from women/men who have been involved for a while

and their outcomes. Research those who have made it work for any length of time with a narcissist or megalomaniac. These stories are few and far between. I’m not saying that it is impossible. Anyone CAN change. Few megalomaniacs, however, DO change.
My blog “Torn” is dedicated to helping women and men like you avoid starting down the nightmare of a road that is a relationship with a narcissist (megalomaniac). Please, please, please do your research!