The most beautiful part of human interaction is our ability to connect and empathize with others. It's what makes a conversation full of life and understanding. Of course, there are moments when we aren't so understanding and compassionate. Some may have these moments more than others but it's also a normal part of being human. The selfish streak that lives within us all also makes us more understanding to an extent.
But what if that's all there was to someone? An ugly chimera of selfish and egotistic behavior had risen to the fore and refused to be chained any longer. What could it be? Narcissism. And not just that egotistic side that we're all entitled to every now and then. Narcissistic Personality Disorder is a long-term mental disorder where one affected by it has an enlarged sense of self-importance and a grandiose-like attitude. The disorder isn't necessarily too bad for ones diagnosed with it, however, it is most definitely difficult for those with NPD to make any healthy relationships.
Traits that can indicate narcissism could be a lack of empathy, an excessive need for admiration and attention, aggressiveness towards slight changes. Because of this, most around the narcissist tend to feel abused or feel inferior. Many who are in relationships with narcissists have grown an inferiority complex, as their partner has made them feel so. However, there are those with NPD who use their "suffering" to gain attention. Through their falsified sadness, they hope to seek the empathy they lack.
That is not to say that people with NPD can't function at all. In fact, it's quite the opposite. Most diagnosed with NPD are wealthy and successful individuals. Researchers have been seeing a connection between social status and NPD for a fairly long time now. Another trait of narcissism is engaging in outrageous behavior or seeking attention through certain mediums. It's why an unsurprising amount of celebrities have been diagnosed with this disorder. It couldn't be a coincidence. However, we can't prove that wealth, fame, or success cause NPD. Some hypothesize that NPD develops at a young age from lack of attention in infantile stages. Others say that NPD is a result of the exact opposite; it could have relation to parents who shower their children in praises and raise them up on pedestals.
Though we may not know how it comes about, there is a way to make things better for the ones who care about their narcissistic friend. One way is for them practice empathy and begin imagining the emotions of another person. It may be difficult but be there to remind them. Above all, be patient with them. The effort they put into understanding someone is a sure sign that they're growing.