OK, you have to get the depth map into a new Alpha channel in the colour image. Use this to create a selection, and apply whatever kind of blur you want.

If you use the lens blur feature in more recent versions of Photoshop, you specify the depth map in there and have more control over where the focus is.

There's also a depth of field plug-in by a chap called Richard Rosenman which uses a depth map, but whether it has any benefits (it's not cheap) over the one mentioned above, I'm not sure.

---

Windows 10 x64 Pro - Intel Xeon E5450 @ 3.00GHz (x2)

PoserPro 11 - Units: Metres

Adobe CC 2017