I am a 15 year old teenage boy and when I was younger about 6th grade I suffered from trauma. My mother tried taking her own life and for the next two years I was putting myself into the clique "emo". Since then I have always sought attention from everyone, doing things I would not normally do. Telling people bad news so I could see the attention they gave me for telling them, posting things on websites out of a seek for attention. My friend and I were just talking and I went through a couple years of drug use. I am now trying to figure myself out and why I do things sometimes. I was looking up childhood trauma and found out something that perfectly describes the way I act. Can an event like finding your mother overdosed in a closet laying on the floor, cause a person to develop a pathological narcissist tendency? I've gone to therapy before for drug use, and I know I always used drugs to show people I had a problem and needed attention. Are these things a narcissist would do?
Finding your mother after she overdosed sounds like a terrifying experience. But such a trauma does not make a person into a narcissist. Those tendencies form over a long period of time during early childhood, and usually have a lot to do with being neglected. I imagine a depressed, suicidal mother wouldn't have much energy left to be a loving, attentive parent. That said, it doesn't do any good to label yourself a "pathological narcissist." It is our basic human desire to be loved, adored and appreciated. When we don't get enough of this (or the parent is narcissistic and self-absorbed), we develop a "false self" to feel secure, while really, deep inside there is a feeling of emptiness, anger or insecurity.
It's all about learning to love your real self - beyond appearances and images.
As for the trauma you experienced - I strongly recommend seeing a good qualified therapist (preferably one that uses EFT/Meridian Tapping), to deal with that traumatic memory. As you've already recognized, an emotional trauma such as that can have lasting consequences for years to come. EFT is an excellent method to quickly neutralize that traumatic memory.