I'm sorry you are suffering from PPD. I hope you have someone to talk to or help you. It can be a really hard thing :( On the topic of longtime friends changing after baby, I had the same thing happening. I have come to the conclusion that people come and go in different stages of your life. You change, your life changes and your friends change. It is not really a personal thing, more of a natural flow of life. It sounds to me that you and your friend are taking different paths in life. I don't think it is something that you can change by talking less about your child or changing what you do. It is such a big part of your life and something to be proud of. Also your priorities are different and so are the priorities of your friend. Sometimes it can work but most of the time it can be quite difficult to find subjects that you can both relate to. Different people fit in different stages of your life. And sometimes you CAN have friends that will last a lifetime. So I don't want to make it sound like it is impossible. But if I read your story it sounds like she is already drifting to a whole other stage than you are. I would ask myself; is that a direction you also want to go? If she talks bad about her other friends to you, does she do the same about you? Is this the kind of person you want in your life and around your child?

Is it a possibility to have an open and honest talk with her about your feelings and hers? Maybe she can tell why sometimes it gets weird and whats bothering? And maybe you can tell her your concerns? Does she support you now you are suffering from PPD? Because a friend should also be there for you in your bad times.

On another note: I personally wouldn't want someone around my child who is dependend on drugs and alcohol, not even a long time friend. But that is another subject.

I hope I don't sound to harsh. English is not my first language so nuances can be difficult.

I hope you can find a way to make it work for you :)