"Just Say No"

Peter Hitchens has posted on marijuana and drugs, and his opposition to their use and legalization.

While I was at the opening of the studio, the familiar smell of marijuana was in the air.

Choosing to induce pleasure through the ingestion of taking of some chemical [for example, the use of alcohol] can be permissible, or is not always contrary to the human good. But deriving pleasure while simultaneously obliterating or diminishing the use of reason?* Or deliberately surrendering autonomy/self-control by altering the brain? That is sinful, although the act's repugnance to reason might not be so clear to the untrained or to the vicious. For me, the use of "recreational" drugs is rather repulsive, and I would not consider using drugs because of the importance I place on reason and human agency. That's not my sin. Though I won't say that in severe circumstances it might not become more tempting.

*Could it be justified through the principle of double-effect, i.e. I intend to derive pleasure by taking this drug, but I do not intend to lose self-control or the use of reason?