People use drugs for many reasons, and we're not all running from something. In fact, some people use drugs to run towards something, looking for meaning, although you could call that running away from futility and meaningless.
Personally, I use drugs just to escape. Whether it's to escape the perspective I have, the feelings I'm experiencing, the thoughts I'm having, irrelevant.
I don't care why, when you're trying to escape something it begins with you. Life just is, it's how you relate to it. Whether you're filling one desire, whether it be loneliness, or ennui, or unachieved goals, or what, all you're doing is replacing one desire with another. The desire to feel better, and when you achieve this through drugs, and this desire grows, addictions seep in.
It also depends on the drug really, when you lump drugs into one category it just muddles the lines.
I use drugs to escape really. To focus my attention from something negative to something different.
Drugs can't fill the void of being lonely, or not having meaning, or not having the person you once had in your life, or not having the childhood you wanted. Drugs won't change your past, they are able to change the way you perceive it.
Drugs can change the present. Drugs can take you from one polar to the converse polar.
Whatever it is you're trying to escape, the drug is redundant. *excludes w/d
Let's say you're feeling (insert emotion here), this emotion is transient, and you're going to feel something else very soon. The thing is, some emotions are reoccurring, you get stuck in the perpetual loop of suffering where you're no longer trying to escape just an emotion, you're trying to escape yourself.
The emotions you've experienced for so long become a part of you, they're no longer a mood, they're now an attribute.
You try to escape this, but you can't. You're stuck with yourself, as soon as you sober up you have to face yourself.
Maybe I'm just a really troubled, fucked up person. I know there are people who use drugs in benevolent ways. There are healthy, stable people with no problems to run from, who use drugs and learn and grow.
Then there's me. I'm just one festering crock pot of shitty emotion and broken destructive apathetic thoughts. I use drugs because they allow me to derive some form of pleasure from my otherwise meaningless life. I use drugs because they give me a break from myself. I use drugs to lift my mood. I use drugs because I don't like being myself, and they allow me to stop being myself.