To a non-BDSM person, the closest way to explain sub/Dom drop is as follows. You train hard for an endurance event. You take part it tires you out but you are happy as you cross the finish line. Sometimes a few min later sometimes the next day as the feel good hormones wear off you suddenly start feeling down as if wondering what is next. This is the same hormonal effect as sub/Dom drop. It does not mean the endurance event abused you. You went into it willingly. It is experienced by many top athletes especially if the season ends or they have an injury which prevents the what next. It is a body's natural high. So far from abuse. It is a well documented medical and psychological effect.