Wednesday makes a good point: how are you defining "Christian"?
Since the vast majority of Americans, even those who never set foot in a church, consider themselves "Christian," I would suspect the vast majority of people with drug addictions are, technically, Christians.
Hell, every Irish Catholic with a drinking problem is, technically, a Christian with a drug addiction.
By the same token in a country that was predominiately Jewish or Muslim, the majority of drug addicts would be Jewish or Muslim.
You need to define your group more accurately.
