Volume 8 Issue 2 February, 2018
Consultation Liaison Psychiatry PATHOLOGY
The mental health though considered as clinical diagnosis, need thorough lab workup to identify (Positive test) to rule out (Negative test), monitor rarely, prognosticate the disease process.
To understand in brief you can classify the laboratory role:
1) To identify the disease process
This is common in lab to be seen for drugs of abuse in urine/blood. The drugs are chosen to suit the clinical use of that region and abuse pattern. Sometimes false positive are common because of the technology used is lateral flow Immunochromatography which are highly sensitive. Then tests need further testing by mass spectrometry based confirmation; however, it is of clinician choice. The important aspect is identity of sample, as per standard protocol one cannot bring Urine sample collected at home. To add you can also think of Vitamin toxicities which can be diagnosed by Vitamin Assay.
2) To rule out the diagnosis
This is usually non specific and involves many tests including radiological tests. Eg: Lead levels in suspected heavy metal poisoning, thyroid hormone level in anxiety disorders, etc. Many instances of patient walking to the lab also request these tests especially who have hypochondriasis and somatoform disorders.
3) To monitor disease/drug
It is very important in most cases to do drug level like lithium, Valproic acid, and others. These tests are reliable as technology used is ECLIA/ CLIA ElectroChemiLuminescence Assay/mass spectrometry. NABL/CAP Accredited laboratories practice of critical reporting system. If any value is found in toxicity level, they immediately report to the clinician. In cases you not getting such alerts, one should advise the lab to start critical alert concept.
4) Prognostication
This is usually not based on laboratory. The utility in most cases is limited to monitor general health.
Another aspect of worth discussion is testing of HIV. Laboratory conducts counseling to all patients who get tested positive while handing over their reports as legally cannot be revealed to any other person (confidentiality). Also note that the screening tests are misleading in patient on chemotherapy pregnancy, animal handlers, shows high false positive results. These cases to be referred to tertiary laboratory for three methods testing including Western blot to confirm.
Lab medicine is indeed a big ally to help the patient and physician and as well in keeping healthy society.