I think the difference between depression and revulsion boils down to a few important aspects:
1) depression is an illness, revulsion ('nibbida') is not;
2) depression is a 'rolling in sadness'; revulsion is a smooth (samadhi should not be disturbed) focus on the drawbacks of phenomena (not personal loss of people/profit/life etc)
3) depression is destructive, revulsion is productive- it leads to dispassion ('viraga') and eventually on to attainment of stream entry (in the first vipassana 'cycle').
4) depression is unpleasant; revulsion is ..not that unpleasant
5) depression is caused by inability to find a healthy coping mechanism to a life problem(s), while revulsion is caused by the development of successive insights, culminating in stream entry
6) depression causes loss of function (inability to do anything that they would otherwise do), revulsion does not lead to loss of function- it is a temporary dip in mood caused by really understanding something (it is an appropriate reaction to the perceived insight).
7) depression is a misfortune, revulsion is a auspicious sign -that insight is developing well, and that you have reached a point of no return in your journey to stream entry.
8) depression is 'just unhappiness', revulsion is a positive sign that something is going right in your vipassana
9) depresion is quite useless, revulsion is extremely useful in inserting insight deep into your subconscious so that they are not lost.
10) depression is a waste of time, revulsion is the most useful use of time of all 'negative' moods.
11) depression weakens you as a person, revulsion strengthen you as a person (to face hardship)
12) depression is akusala (unwholesome karma), revulsion is kusala (wholesome karma)
13) depression makes a person think negatively of themselves, revulsion does not.
14) depression causes a person more likely to become depressed again in the future, revulsion makes you more likely to attain insight easily again, if you have stopped your vipassana temporarlily.
15) depression leads you to have aversion towards life, revulsion cause you to become detached (or a better expression 'non-attached) from life.
16) depresion leads you nowhere, revulsion leads you 'upwards' ('opanaiko') - one of the qualities of the dhamma.
17) depression leaves you with nothing, revulsion leaves you with insight
18) depression is unpleasant, revlusion is accompanied by samadhi- so it is not entirely unpleasant
19) depression is a hiding of the Truth, revulsion is a revelation of the truth
Hope that clarifies,