"Impact upon themselves" simply refers to the sufferer often needing something quite impacting upon their life / lifestyle in order to change for the better, ie. sometimes the act of separation does it; another accident does it; etc. The sufferer often needs something that impacts their personal choice before they will make a significant effort to change themselves for the better. Often a sufferer will just lay in the lifestyle and surroundings they have become accustom too and accept that, though if changed dramatically to no longer favour them, can make them change for the better.

Again, sometimes these significant events only make them more stubborn, sometimes makes them worse. Risky, though typically the way in which a person makes change from their "normal" and safe surroundings.