When I put up my post the other day responding to a Salon article accusing Army doctors of inappropriately changing physical profiles to deploy more people, there were some things that I didn't make clear enough. I did not address mental health at all, and my discussion of the physical standards was very limited - I addressed only the accusations involving doctors altering profiles to make soldiers fit the standard for deployment. I did not address the questions about whether the physical standards for deployment have been lowered. Both of these issues have come up since then - the question of changes to physical standards was raised in the comments to the first post, and Dave Munger has an article up at Cognitive Daily looking at the mental health issues.
I think that there's little doubt that the physical health standards for deployment have been lowered - and lowered considerably - since the start of the Iraq war. I'm not sure if the mental health standards have been lowered as well, or if there simply wasn't much in the way of detailed mental health standards to begin with. The changes are the result of the stresses to the military caused by the continued high deployment rate.
Basically, it comes down to this: the deployment pace has required the Army to rethink their old physical health policies for deployment, which were focused on making sure that everyone who deployed was fit enough to fight. The new focus is no longer on "is this soldier in shape to prod buttock and take names." Instead, it's become something more along the lines of, "is this soldier fit enough to do anything in the combat zone." Whether or not this change of focus is entirely a bad thing, or whether it is a realistic response to the demands on the force, is at least somewhat debatable, as is the question of what the appropriate standards are.
With mental health, the situation is more difficult. There are a lot of soldiers with known mental health issues, and there are a lot of soldiers who deploy on antidepressants. In part, this is probably because there are more soldiers with mental health issues than there used to be, particularly as the number of troops on their second, third, or fourth deployment continues to climb. In part, I also suspect that it's because, as bad as the Army can be at identifying and treating mental illness, they are better at it than they used to be.
In both areas of health - physical and mental - there is no doubt that the Army is deploying people with identified concerns. There are significant questions in both cases as to whether the Army is deploying people with health issues appropriately, and whether they are being deployed with access to appropriate health care. These questions absolutely need to be addressed, along with a wide range of other ones. (For example, I don't know of any study that has looked at PTSD rates after multiple deployments.)
And, of course, there is no doubt that these issues would not be as much of a concern if the active duty volunteer force was not stretched to the breaking point.