Having listened to the audio segment, it sounds like the effect of the drug is akin to when people dissociate. When I think about something frightening, my emotions deaden and I am able to deal with it. It sounds as if the drug does the same thing, with the same potential side-effect. I have trouble feeling much of anything most of the time, particularly strong emotions. The drug could potentially weaken the portion of the brain that induces strong emotional responses.
I understand the reason behind wanting to use such a drug, but what if the effects are not reversible?
Every day I die again, and again Iím reborn/Every day I have to find the courage/To walk out into the street/With arms out/Got a love you canít defeat/Neither down nor out/Thereís nothing you have that I need/I can breathe/Breathe now - U2