just to add what @Asmo rightly pointed out,is that addictions are a symptom of internal and external forces.

when we consider the state of our society and it its inherent social structures,and we compare addiction rates and suicide rates,i feel there is sufficient evidence for concern.

just look at americas suicide rates.
http://afsp.org/about-suicide/suicide-statistics/

we can see a steady increase.
when we factor in military suicides,which have been averaging one,to up to 22 a day since 2009.the larger picture becomes incredibly disturbing.

my point,which is right with asmo,is that while one group kills themselves due to hopelessness,emotional stress or an inability to cope or adapt in these trying times.

the addict is doing the same thing,for the exact same reasons.just on a slower and more precipitous path of self-destruction.

when asked as a child what they wanted to be when they grow up.no child ever answered that their desire was to become an addict.

the "war" on drugs,
is a war on people.

and treating this as a legal/criminal problem is missing the point entirely.
this is a social issue,that can be treated by providing social solutions.

dr bruce alexander discovered some amazing results in rats you may find interesting @MilkmanDan:

http://www.brucekalexander.com/articles-speeches/rat-park/148-addiction-the-view-from-rat-park

The story of Rat Park in comic form: http://www.stuartmcmillen.com/comics_en/rat-park/