In 2021, Facebook Inc. changed its name to Meta. At first glance, the updated name simply reflected that the company had grown to own not just the Facebook platform, but also Instagram, Threads, WhatsApp and a desire to branch out and include virtual reality [1]. The term "meta," however, has a deeper meaning. Meta is short for metaverse, a word coined by Neal Stephenson in his dystopian novel Snow Crash. The metaverse is a hypothetical future state where people "live" in a virtual world. It is a common trope in film and literature, including popular films like The Matrix and Ready Player One. Although a virtual-reality-based future appears unlikely, people do spend a considerable portion of their wakeful hours consuming digital media (e.g., social media, watching films, listening to music) [2]. One might wonder what people spend all their time looking at and whether it matters. In the context of substance use, the 12 papers in this special section aim to address both of these important questions.