Anyone ex-brit mil should have been taught the same thing about VRS and it goes as follows:
1. Heli in the free air hover - root of blades at higher AoA than tips due to washout and rotational speed - total thrust of disc equals weight so hover maintained.
2. Rate of descent eg 500' - 1000' fpm allowed to develop (for whatever reason) - tips start to experience recirculation (loss of thrust) root of blade reaches Cl max and starts to lose thrust (stalled aerofoils still produce thrust) - net thrust of disc reduces and RoD increases. At this stage power available maybe sufficient to overcome RoD - if not then settling with power is occurring and step 3 is next if the ground doesn't get in the way.
3. As RoD is allowed to increase, more of the tip experiences recirculation and more of the root stalls -compounded by raising the lever which spreads the stall outboard from the root - further loss of thrust and acceleration downwards.
4. Eventually, only the central portion of the blade that is neither stalled or in recirculation is producing any useful thrust - nothing like enough to match the weight so the ac continues to accelerate downwards. The air trying to escape round or through the rotor gives random pitch, roll and or yaw and makes recovery from just forward cyclic very difficult.
Recovery - lower the lever, to auto if possible and try to achieve airflow across the disc with forward cyclic.
MOSTAFA - Nick is right, in fully developed VRS raising the lever will not make the ac fall faster as it is already going down as quickly as it can - however, in the incipient stages, raising the lever can exacerbate the problem and take you into fully developed VRS.
Nick's stuff is excellent, but for mere mortals a more than adequate explanation is in AP3456