Are you feeling crabby or stressed? Or are you not keeping up with your responsibilities at work, school or in your relationships? The reason could be that you’re spending too much time online, according to research published Wednesday in the journal PLOS One.

People who use the internet problematically are more stressed, have worse moods and are more likely to neglect other parts of their lives, according to the study of 900 German adults. Problematic internet use is when people use apps excessively, causing distress or impairment.

“Stress and a negative mood leads to a higher temptation” to use the iInternet, said Andreas Oelker, a doctoral student at the University of Duisburg-Essen in Essen, Germany and lead author of the study. Using the internet problematically could then make things worse.

The ongoing research sheds light on a problem that isn’t classified as a disorder but possibly should be, said Silke Müller, a postdoctoral research assistant at the University of Duisburg-Essen in Essen, Germany and co-author of the study. One limitation of the study is it only tracked adults, so we don’t know if the same thing happens to kids, Müller said.

The findings make sense because we know spending too much time on screens makes people unhappy, for many reasons.