There are many ways to diagnose illnesses besides blood tests. Oriental doctors feel the pulses and look at the tongue, smell the breath, and sometimes taste urine (ick!). These methods have been used successfully for millenia before Western medicine.
I say it is objective because the patient must meet certain specific, measurable, observable criteria.
Not yet. There are studies in progress looking at genetics as well as other factors. But quite honestly, I don’t know if one will ever be determined. What we can do is treat what we can see (symptoms) and sometimes this is done with medication, vitamins, minerals, and behavior therapies.
You seem very angry, Jaime. Some people with mental illnesses have trouble with anger. Some are angry because they are ill. Some are angry because psychiatry cannot make them well. One thing I can tell you that is 100% true:
“This you know, my beloved brethren. But everyone must be quick to hear, slow to speak and slow to anger; 20for the anger of man does not achieve the righteousness of God.” James 1:20
Harboring anger and resentment makes the human soul sick, whether one has a mental illness or not. The way to get rid of it is forgiveness. One must forgive all those one feels harmed by . In your case, this might include the profession of psychiatry. Another way out of this illness is to pray for them.
"But I say to you, love your enemies and pray for those who persecute you, 45so that you may be sons of your Father who is in heaven; for He causes His sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous.…Matt. 5:44
Bless them, love them, and pray for them. Then you will be healed from anger and resentment.