If you’ve ever pushed back your bedtime to watch “just one more” episode of Orange Is the New Black, or lay in bed wide-eyed after streaming three exhilarating hours of Game of Thrones, this new research probably won’t surprise you. A new study in the Journal of Clinical Sleep Medicine is the first to link binge-watching with poorer sleep quality, more fatigue and increased insomnia.

Not only does on-demand TV tempt us to keep watching episode after episode, say the study’s authors, but the shows are also designed to draw us in, boost suspense and emotionally invest in plot lines and characters. This can lead to excitement and increased arousal, the research shows, which can translate into increased cognitive alertness and an inability to get the shuteye you need.

The study involved 423 young adults, ages 18 to 25, who completed online surveys about how often they watched television, both conventional TV and streaming services. They were also asked how frequently they “binge-watched” shows, defined as watching multiple consecutive episodes of the same show in one sitting, on any type of screen. They also answered questions about their sleep quality and how tired or alert they felt throughout the day.