I wonder what that means for Pagans, since there's nothing inherently Christian about the use of natural trees and lights and many Pagans (and some Christians) believe it to be a Pagan influence on Christmas?

Christmas trees bum non-Christians out, study shows: Even an unspoken reminder of the holiday made some feel subtly excluded

Here's a new twist to the annual "War on Christmas" debate: Reminders of Christmas can make religious minorities feel ill at ease — even if they don't realize it.

When people who did not celebrate Christmas or who did not identify as Christian filled out surveys about their moods while in the same room as a small Christmas tree, they reported less self-assurance and fewer positive feelings than if they hadn't been reminded of the holiday, according to a new study.

Also...

In both versions of the study, the Christmas tree failed to spread holiday cheer equally. Non-celebrators reported fewer positive feelings and less self-assurance in the Christmas room. Christians and celebrators, on the other hand, were mostly cheered by the tree, with one exception: Celebrators reported feeling more guilt when they were in the Christmas room. That finding suggests that even for Christmas-lovers, the holiday can be stressful, Schmitt said.

The religious minorities and non-celebrators weren't looking to be offended by reminders of Christmas, the study found. After the surveys, the researchers explained the goal of the experiment to the volunteers and asked each of them how they thought the presence of the tree might affect their mood. There was no difference between the responses of Christians and non-Christians or celebrators and non-celebrators. All thought Christmas decorations would make them happier.