Booze and drugs are plenty prevalent in It's Always Sunny in Philadelphia, but now, we known which member of the gang is the biggest drunk, thanks to a new study that examines the show's use of drugs and alcohol.

It may come as no surprise, but It's Always Sunny's biggest lush is Charlie Day's Charlie, by far, with 324 references to booze and drugs throughout the 12 seasons that have been aired. His substance use (and abuse) more than doubled Frank's (Danny DeVito) number, who, with just 140 references to drugs and alcohol on the show, is actually the gang's cleanest member.

That's according to a new study on Alcohol.org, a website owned by American Addiction Centers that reviewed the series entire run — excluding the current 13th season — to determine their rankings. In the middle of the pack is Dennis (Glenn Howerton) with 251 drug and alcohol references, Dee (Kaitlin Olson) close behind with 249, and Mac (Rob McElhenney) in fourth with 217 mentions.

On average, that's 21 mentions or visual depictions of drugs and alcohol per episode for 134 episodes straight. The show's peak use of drugs and alcohol use occurred in Season 10, which the study says had about 31 alcohol or drug references per episode. Season 12 appeared to see the gang clean up their acts, with just 6.6 references per episode.

The worst offender across the series' run, of course, is season 10's "The Gang Beats Boggs," in which the gang attempts to drink 70 cans of beer each on a flight to Los Angeles. Overall, that episode contained 183 references to drugs and alcohol. This season, the gang revisited the plot with "The Gang Beats Boggs: Ladies Reboot," which no doubt increased Dee's total number.

In addition to being It's Always Sunny's biggest drunk, Charlie also has used the largest range of drugs in episodes of the show. Like with the rest of the cast, beer is his drug of choice, but the character has ingested everything from steroids, poppers, and marijuana to cocaine, LSD, and various inhalants. Frank, on the other hand, has more discerning tastes, and has consumed just seven drugs in total across the show's run, including the fictional Adderall/Ritalin cross, Ridderall.

While the show often plays drug and alcohol use to comic effect, the Alcohol.org study notes that substance abuse is "no laughing matter." According to the study, some 17 million Americans have an Alcohol Use Disorder, which is defined by symptoms like "cravings, spending an excess time drinking, drinking longer or more than intended, and experiencing…dangerous outcomes as a result." Put that way, it looks like every member of the gang has a problem.

"Alcoholism is a disease that manifests itself in the form of physical dependency and finding treatment won't be the same for everyone," the study notes. "If you or someone you love is suffering from alcohol misuse or addiction, help is here for you."

It's Always Sunny airs Wednesdays at 10 p.m. on FXX.