dope

Reader's Digest 6月号の記事、Las Vegas Confidentialの一節です。
A first-time visitor, I want to peel back the facade and see what makes Las Vegas tick.
I plan to go behind the scenes at some of the town's most famous casinos to get the inside dope on the city that, as Frank Sinatra once said in a film, is the only place where money really talks. It says "goodbye".
この "tick" の用法（"what makes something/someone tick" Ref. http://blog.alc.co.jp/blog/3302827/archive/2011/04/23 ）は以前とりあげた表現ですね。　今日気になったのは "dope" の意味です。 Las Vegasからの連想で麻薬が頭に浮かんだのですが、前にinsideがあるし、文脈からしても違います。　辞書を見ます。
・Macmillan Dictionary: the dope all the information or latest news about someone or something; dope on: What’s the dope on Kate’s new boyfriend?
・Merriam-Webster's Online Dictionary: information especially from a reliable source: the inside dope
・Infoplease: Slang.information, data, or news: What's the latest dope on the strike?
語源を見ると、なんと薬の意味と関係がありました。
Sense of "inside information" (1901) may come from knowing before the race which horse had been drugged to influence performance. （excerpt from Online Etymology)