For us it is more straight forward... Islam basically came down to protect human life, livelihood, dignity and mind... So anything that messes the human mind is forbidden... these include these drugs of abuse...
There is a misconception amongst a lot of people in Pakistan that Quran forbids alcohol only but in reality the word used in Quran is Khimr which means something that covers... in context something that covers the mind/intellect... this includes all intoxicants... so its not just alcohol... but other substances of abuse also...
Interestingly compared to Europe and America... we are a utopia when it comes to drug abuse in the society... That is actually due to the Islamic influence...
If everything intoxicating was banned..
then we should stop using sedatives in an operation.. hmm??
Bhang, Naswar, Cigarette's..
utopia Indeed