I remember seeing some research draw this conclusion as well, but IMO it's the wrong conclusion since a lot of the data in the studies I saw seemed to indicate the issues stemmed from the actual switch, not whether we did things an hour earlier or later. It's that transition period that fucks things up. While I'd prefer permanent DST, I don't care that much. I just want the endless, stupid dance to stop and never switch again.
2/3rd of the research in that link is anecdotal. Further, I still want DST to be permanent. I like it dark in the morning and light further into the day.