This is not a book that one could actually "like" because it's really depressing to read. But it is an important and interesting portrait of 70's Berlin drug scene. Many german teens were required to read this in school when it came out to make them understand about drug abuse. It would be interesting to know how many of them actively decided to never try drugs after the lecture of this book or after seeing the movie. (Quite a lot I guess, both the book and the movie are VERY graphic about the horrors of drug withdrawal) Also there was a new Amazon Prime Series not too long ago, but it wasn't THAT graphic. It's really authentic and you just have to care about the characters.
The saddest thing is that - although this depicts a situation about 50 years ago - many things haven't changed. It is still difficult to get people into drug therapy, still parents aren't watchful enough, still the school system is overwhelmed with difficult children, still drug dealers are taking advantage of teens who don't know the risks of certain drugs or who want to make "quick money" by selling drugs.
I could go on.
The only way to raise awareness is through books like this. So: Highly recommended, but be aware that it's not a fun read, also take a look at the content warnings!