I don't think their is a karmic punishment for suicide. I think that is all talk of control... However, we all come here for a reason. We had a reason to be here, and taking our lives may of prevented us from finishing that reason. There is also the possiblity that it was known all along that one would of committed suicide so it may not have much of an impact.
I don't know if there are any ramifications of it, but IMO, it is a negative act that you are placing upon yourself. So that negativity and mindset may send you into a place of confusion and being lost in the next realm as you try to find yourself.
I have also heard some say that suicide causes you to come right back without a break. Right back into the same circumstances.
Suicide for what reason?