With the technology that's out there today, I don't understand why we cannot "measure" and "examine" exactly what is going on inside a person's brain in a more precise and definitive way...
For example: If we KNOW that there indeed are neurotransmitters in our brain such as dopamine, serotonin, nor-epinephrine, etc, etc, why can we not take it one step further and measure those things accurately? We are most often left with subjective data and depending upon how someone says they feel and their BEHAVIORS.