Alcoholism has a lot of similarities to NPD. However, some individuals suffered trauma and do have ptsd and self medicate with the alcohol and other drugs as a way to escape their emotional pain. Often when a person finally gets sober, that is if they do get sober, it's not uncommon for that person to begin experiencing all the symptoms of ptsd. I have been learning about that from therapists who treat individuals who had addictions and alcoholism that also suffered from ptsd.