A question we have all been pondering for a while.! Our brain functions are so complex that after decades of scientific discovery, still, developing a diagnostic psychiatric test seems very far away.
By Dr. Allen Frances*
*Allen Frances, an emeritus professor of psychiatry at Duke University, chaired the task force for the Diagnostic Manual, DSM-IV.
When the third edition of psychiatry’s manual of mental illness, the DSM-III, was published 30 years ago, there was great optimism it would soon be the willing victim of its own success, achieving a kind of planned obsolescence. Surely, the combining of a reasonably reliable system of descriptive diagnosis with the revolutionary new tools of neuroscience would quickly yield a deep and broad understanding of psychopathology. And just as surely this would translate into standardized biological tests that would replace the cookbook listing of subjective symptoms and subjectively evaluated behaviors that comprised the DSM-III criteria sets.We have learned a great deal in the past 30 years, but perhaps the most important lesson is that the brain is ineluctably complex and reveals its secrets only slowly and in very small packages. There has been no low hanging fruit. The expectation that there would be simple gene or neurotransmitter or circuitry explanations for schizophrenia or bipolar or obsessive-compulsive disorder has turned out to be naïve and illusory. The problem of teasing out heterogeneous clinical presentations in psychiatry is compounded by the fact that they also have heterogeneous underlying mechanisms. There will not be one pathway to schizophrenia; there may be dozens, perhaps hundreds. Biological tests that appear to be associated with schizophrenia are never useful for making the diagnosis because they always show more variability within the category than between categories. And seemingly intriguing findings usually don’t replicate.
Most troubling is the fact that the overwhelming majority of prescriptions for psychotropic medicines are written by primary care physicians who often have little training in psychiatry; little time to perform an adequate diagnostic evaluation; a tendency to depend on tests rather than talking to patients; and too great a susceptibility to quick trigger diagnosis and poorly chosen pill solutions (fostered by aggressive and misleading drug company marketing). The lack of precise and easily available biological tests in psychiatry permits much loose diagnosing and cowboy prescribing..