opiate addiction may not be that prevalent in Bangladesh; but from what I understand Methamphetamine (popularly known as 'Yaba') is a significant problem.
http://www.dhakatribune.com/bangladesh/crime/2016/12/19/stud...
https://news.vice.com/article/yaba-the-madness-drug-is-findi...
the history of 'Bengal Opium', especially its production & distribution is indeed a fascinating one. The historical fiction by Amitav Ghosh in his "Ibis Trilogy" is very illuminating: