If your office has an open floor plan, it could be affecting your mental health as well.
This floor plan has become popular because of the implied easier access that co-workers have to each other, and the expectation that it helps with team-building.
The problem is that there is nothing to break up noise, there is no privacy, and there are constant interruptions as colleagues call across the room to each other.
All of this contributes to an inability to focus easily and a lot of stress as people have to work harder to concentrate.
If your office has one of these open floor plans, the best way to save your sanity is to wear noise canceling ear buds.