Alex Gibney traces the raucous life and career of iconic author Hunter S. Thompson (“Fear and Loathing in Las Vegas”), the original “Gonzo” journalist — and as this revealing film demonstrates, what an original. Among his many exploits, Thompson covered the 1972 presidential race for Rolling Stone with arch candor and plenty of wild-eyed, drug-and-booze-fueled paranoia.

Coming off his celebrated doc on torture, “Taxi to the Dark Side,” Gibney turns his attention to the crazed energy and demented insight of Thompson, whose first-person reporting style boldly rejected the voice-of-authority model of broadcast news and print journalism. Drawing on rare archival clips, Super 8 home movies, dramatic readings by Johnny Depp, and interviews (with the likes of George McGovern, Pat Buchanan, artist Ralph Steadman, and editor Jann Wenner), Gibney paints the fullest portrait yet of this Nixon-hating, Wild Turkey-gulping American individualist. Go “Gonzo!”