Use of cigarettes or e-cigarettes was linked with more sleep difficulties in a recent Journal of Sleep Research study.

The study included 1,664 college students, 41% of whom reported ever trying or currently using e-cigarettes and 29% of whom reported ever trying or currently using traditional cigarettes. Across all groups, average sleep scores indicated poor sleep for most students.

Similar to traditional cigarette smokers, e-cigarette users reported worse sleep than individuals who did not use cigarettes. Users of e-cigarettes reported greater use of sleep medications than traditional cigarette users.

“Given that poor sleep and substance use, including e-cigarette use, are both common among college students, understanding how e-cigarette use may impact sleep is crucial given its association with numerous health concerns,” lead author Emma I. Brett, PhD, of Oklahoma State University, says in a statement. “Since we found that even non-daily use of e-cigarettes was associated with worse sleep health, this may be a useful target for prevention and intervention efforts.”