From the first time I tried alcohol ( and subsequently marijuana and then cocaine,lsd, various other chemicals) I really really liked the state of intoxication induced by them. Eventually that enjoyment lead to the negative consequences and discomfort , but since the enjoyment of the intoxication never waned , I could always rely on the experience of the enjoyment , even if it proved to be fleeting. Doing that long enough lead to me feeling as if the only two choices left were one full time intoxication , partly from the physical discomfort of withdrawl and also of the psychological need or want to not look at the 'situation' , or giving up intoxicating myself .
Evolutionary 'roots', neural pathway ect... for too generalized for my recovery from my addiction(s),they were far too phenotypical.