Mate, you took what I said out of context and tried to make a point that I wasn't making.

Read the entire paragraph and the surrounding text, it's there for a reason.

From the research cited:

"By increasing dopamine release—as heroin alone does not—dopamine antagonists elevate extracellular dopamine at the nerve terminal, desensitizing the system to the antagonist and, in this case, requiring more heroin to be effective. In any case, dopamine antagonists do block opiate self-administration [102]; the lack of compensatory increases in responding for heroin following low doses of dopamine antagonists [102] does not [105] rule out a role for dopamine in opiate reward."

The opiates themselves don't stimulate the dopamine response, it's the anticipation of the opiates.

Let me put it to you another way. Other drugs cause dopamine levels to skyrocket beyond anything normal anticipation of pleasure could ever do. There's no amount of "maybe" that could boost your dopamine the hundreds of percent rises found when we take amphetamines.

So, you would expect that amphetamine would be more addictive than heroin, as I said in the article—but it's not, it's clearly not. Because dopamine isn't the sole cause of addiction, or even the primary cause, which is what this entire article is about.

Hope this clarifies things.

Try not to isolate a single sentence and interpret that alone.

Cheers.