There are a lot of former seminarians, who were booted after failing "psychological tests" administered because they had such radical ideas as wanting to pray the rosary, who will tell you how well this idea will work.
Who is going to define the criteria for exclusion or ensure the tests provide an accurate assessment of those criteria? The gummit that is trying so hard to take away the right to bear arms?
All of which assumes that psychologists can even come up with a valid test for this purpose. Modern psychology is significantly flawed in that its understanding of the nature of man is based not on the philosophical understanding of the nature of man that has been developed over many centuries, but on a statistical analysis of what man is today -- a reference point that has been skewed by centuries of secular humanistic influences (c.f. Fr. Chad Ripperger, Ph.D., Introduction to the Science of Mental Health).
Psychologists do not have an objective definition of mental health, unlike the physical medical practice which can define objective criteria for conditions such as high blood pressure, heart disease, COPD, or diabetes. How a person "feels" and whether that is to be considered "normal" is very subjective and, as you correctly note, is conditional upon secular humanistic influences.
Even with that, a large amount of the "mental health infrastructure" requests sound even more fishy and self-serving when you consider that the main beneficiary, other than the government by having more people administratively stripped from full citizenship, is big Pharma.
The FDA, when petitioned by Dr. Irving Kirsch of the University of Connecticut under the Freedom of Information Act, released the full files on the six most widely perscribed antidepressants approved between 1987 & 1999. Of 47 trials conducted on the drugs (Prozac, Zoloft, Paxil, Effexor, Serzone, & Celexa), only 20 showed measurable advantages over placebos, which was much a much lower ratio than reported in published literature. It turns out also that the average patient improvement on the drugs was 10 on the Hamilton Depression Rating Scale versus 8 on placebos. While clinically meaningless, especially with side effects considered, it was enough to allow the drugs to be approved as effective by the FDA, where a drug only has to be shown to be 15% more effective than a placebo in two (2) clinical trials - no matter how many failed trials you have to get there.
Source: Michael Murray, M.D., "What the Drug Companies Won't Tell You and Your Doctor Doesn't Know", pp 156-157