How do I deal with a narcissistic brother who may have NPD?

[Misfit]

he refuses therapy, and I feel I am to blame because I had a troublesome youth and was very delinquent as a youth, and feel that may be the cause, and according to my family, that is the cause of my brother's symptoms, but they haven't put a name on it.

[Great]

You are not responsible for your brother's mental illness. It's partly genetic. It seems like your family is looking for someone to blame.

I repeat, you are not responsible for your brother's mental illness.

[Misfit]

My therapist has said he likely does not have NPD. But he said he likely has oppositional defiance disorder.

[ContractedCriminalboy]

Do a course called Knowing Who You Can Trust followed by one called PTS/SP. It has everything you need to know to handle such a person.