It occurs over the process of approximately six weeks, where the actual mental health professionals are in place in Cyprus. If you could divide the 2,500 folks or so—probably less than that, minus Camp Mirage—who are rotating through, it will give you some idea as to what sort of throughput they're dealing with.
You're right, though, that it's for purposes other than just mental health identification—physical decompression, other things too—but it is made available.