The Difference between Protestants and Catholics concerning “Concupiscence”

The author describes concupiscence as “involuntary desire for sin.” Does anyone else see this as problematic? So much of, for example, addictions counseling, is based on the idea that the poor sinner cannot help themselves. Is sin, especially to the believer, “involuntary?” Or is it based on understanding epithumia as strong desire?

This is a difficult area. Epithumia (lust or strong desire) is often condemned. Yet, at the same time, it is not sin to be tempted.

Might it be the difference between desire and nurtured desire. In other words, at a certain level a desire is not sin, but, if unchecked it becomes more intense and thus sinful.