To show how alcohol and drugs effect a user's appearance, a website called Recovery.org used mugshots to average the faces of male and female abusers of marijuana, alcohol, and meth.
For each face in the graphic below, 100 mugshots were merged together using software.
To rule out the influence of race and age, only the mugshots of white drug and alcohol offenders between the ages of 18 and 35 were selected, according to the website. You can read more about the methodology here.
In an emailed statement, Recovery.org says that marijuana users tend to have round features and a full face, meth abusers have sagging skin, sunken eyes, and a grey-ish appearance, and alcohol abusers look fairly normal.
The study doesn't offer and explanation for why pot smokers have fuller features, especially since a recent study suggested that people who regularly smoke marijuana are skinnier.
Recovery.org