Originally Posted by pgardn

This is basically an old genetics theme called penetrance. 100% penetrance means a certain gene will determine some physical/biochemical characteristics for example eye color. If you have the two recessive genes for eye color you will have blue eyes. Now you might put brown colored contacts on... but your eyes are blue.

Most genes do not have 100% penetrance, its somewhere in between. However it is very clear, just like cancer, some people have a GENETIC predisposition to alcholism. Now if they stay away from the stuff, they never become an alcholic. Others have a much lower likelyhood of becoming an alcoholic, but they clearly can if they drink enough.

It is the same way with many mental disorders. Some have a very high penetrance and some require the right environmental conditions to make the disease manifest itself. But make no mistake, depressed people, schizo, have VERY diff. brain chemistry than normal happy folks. Very diff. But because it is not obviously seen (like a missing arm) then people assume it does not exist. But from a biochemical point of view these mental disorders clearly exist.

Originally Posted by Cannon Shell

Though I agree this would most certainly be helpful, the ACLU would have a field day with it as soon as they have run out of terrorists to defend.