It’s sort of trendy to say you’re about to binge-watch Orange is the New Black or Breaking Bad over the weekend, but there’s a much less glamorous side to watching TV for hours on end. Depression and loneliness make a person much more likely to watch TV excessively, and this habit can be destructive to mental and physical health.

Binge-watching is a new phenomenon and, as its name implies, the practice may also reflect a lack of self control.

Researchers from the University of Texas at Austin asked over 300 people aged 18-29 how often they watched TV and how often they binge-watched TV. They also asked the participants questions like, “How often do you feel alone?” to determine their levels of loneliness and depression.

When binge-watching becomes rampant, viewers may start to neglect their work and their relationships with others.

There was a clear link between how depressed or lonely people felt and how often they binge-watched TV. And this may mean that binge-watching isn’t such a harmless pastime after all.

“Even though some people argue that binge-watching is a harmless addiction, findings from our study suggest that binge-watching should no longer be viewed this way,” said lead author Yoon Hi Sung in a news release.

The prolonged periods of sitting involved in excessive TV-watching have been linked to all sorts of chronic health problems. “Physical fatigue and problems such as obesity and other health problems are related to binge-watching and they are a cause for concern,” says Sung.

The other problem with binge-watching is psychological: Watching hours of TV in a day, especially if it’s a common occurrence, is generally not going to help feelings of depression or loneliness improve — it may actually do the opposite.

TV-watching often takes the place of real, person-to-person relationships, not to mention healthy hobbies or habits like exercise.

“When binge-watching becomes rampant, viewers may start to neglect their work and their relationships with others,” says Sung.

“Even though people know they should not, they have difficulty resisting the desire to watch episodes continuously. Our research is a step toward exploring binge-watching as an important media and social phenomenon.”

More research will be needed to understand how TV-watching relates to mental health issues, and to other compulsive behaviors or addictions. Is it that lots of time in front of the tube brings on depression, or is it that depressed or anxious people tend to spend more time watching television?

If, once in a while, you gather with a group of friends to watch a few episodes of House of Cards, it’s probably not such a bad thing. But it may be best to turn off the tube and get out to see people if you suspect that depression or loneliness is what’s prompting you to turn it on.

The study was carried out by a team at the University of Texas at Austin, who will present the findings from the study at the 65th Annual Conference of the International Communication Association in San Juan, Puerto Rico, in May 2015.