If there is a god, then the best evidence of his (?) way is the justice meted out to individuals who take happiness into their own hands. I like it!

All drugs have targets. Mood altering drugs are the subset under discussion. So how are such drugs used? To create a mood you like, rather than what would happen naturally.

So OK let's think about that.

So for an artificial mood change, a drug has to cross the blood brain barrier in some way and cause a large squirt of serotonin from neurons in the pleasure center of the brain. It would be safe to assume that an extreme discharge of happy juice renders the neuron stressed and in need of recovery.

But no. Happy Boy is in control here. He's going to keep popping the pills, or drinking the juice for more more.
No surprise the neurons become overworked and some of them die. The rest change form. Become bigger and misshapen and the arteriols feeding them, break down in places.

That's brings to mind the photos us kids had to look at in science class. You know the bloody alcoholic brains.

Using drugs destroys the exact place in the brain you are trying to target. That is the punishment which can be attributed to God.