[Monty22]

The problems always start when someone goes from just stopping pain to achieving pleasure. Once that line is crossed, they are in deep trouble. All drugs tend to have a tolerance, so they have to get more and more.. Usually quickly.

If they stick to helping pain only, this won't happen as often, since the doses don't reach the 'high' part typically.

[StriperSniper]

The problems always start when someone goes from just stopping pain to achieving pleasure.

Yup, can't disagree with that. Unfortunately that can be a very fuzzy line, complicated by both the physical and mental aspects of it. It takes being highly in-tune with one body and mind to recognize it. It can be very similar to food, some get cravings because of a lack somewhere in their diet. Many can't recognize them for what they are, others can.