Yes, at times the CIA has definitely been in the drug trade
I think it ebbs and flows with administrations and operations. At its ground floor level the CIA is the mafia. I am not talking about analysts at Langley studying Russian or Chinese agricultural output, but rather the folks in operations and the dirty tricks department.
There are a bunch of other super books where you can read about the bipartisan Bush/Clinton drug scandals of the 1980's:
1) Powerburns: Cocaine, Contras & the Drug War by former DEA agent Celerino Castillo, III
2) Dark Alliance by Gary Webb
3) Barry and the Boys: the CIA, the Mob and America's Secret History by Daniel Hopsicker
4) Whiteout by Alexander Cockburn
5) Cocaine Politics: Drugs, Armies and the CIA in Central America by Peter Dale Scott and
Jonathon Marshall
6) Lost History by Robert Parry
7) The Conspirators: Secrets of an Iran-Contra Insider by Al Martin
8) The Big White Lie: The Deep Cover Operation That Exposed the CIA Sabotage of the Drug War: An Undercover Odyssey by Michael Levine and Laura Kavanau-Levine
9) The Politics of Heroin in Southeast Asia by Alfred W. McCoy (from the 1970’s era)
10) Out of Control: The Story of the Reagan Administration’s Secret War in Nicaragua, the Illegal Arms Pipeline, and the Contra Drug Connection by Leslie Cockburn
11) Blue Thunder: How the Mafia Owned and Finally Murdered Cigarette Boat King Donald Aronov by Thomas Burdick and Charlene Mitchell
12) The Mafia, CIA, & George Bush by Pete Brewton
13) Called to Serve by James “Bo” Gritz
Also, google "The Crimes of Mena" by Sally Denton and Roger Morris which they had to publish in Penthouse in July, 1995 because the establishment Washington Post spiked this extremely embarrassing story to folks like Clinton and Bush #41. Another book to get is The Secret Life of Bill Clinton by Ambrose Evans Pritchard. Read that book and you will get a taste on how corrupt the Clintons are. L.D. Brown, Bill's favorite state trooper wrote a book called Crossfire: Witness in the Clinton Investigation in 1999. L.D. tells us wild Bill was fully aware of his very good friend Dan Lasater's drug involvement in Mena. In reality, Dan Lasater was in charge of laundering the drug money along with the help of ADFA where Bob Nash worked.