If we have relationship problems, learning about Narcissism and Codependency as relationship strategies is very helpful. The narcissist is the pathological controller, and the codependent is the pathological appeaser. Learning about these behavior patterns opens up so much understanding about how human relationships work when basic emotional needs have not met early in life.
Generally the information available will make a clear distinction between the two relationship strategies, and how these 2 opposite strategies fit together and supply each others emotional addictions.
The next level of understanding comes from the realization that every narcissist has some degree of codependency and vice versa. When we have made the decision to heal ourselves from being a codependent, we must not exclude the possibility that parts of our mind think in narcissistic ways.
Its great to learn about our patterns of behavior and then raise our rate of healing, but its important to explore all the possible ways we need to heal.