Damian Sendler: Even in the days of traditional psychiatry, practitioners felt that mental illness may be passed down via families. With a heritability estimate of 46.3 percent for neuropsychiatric disorders in general [1], and a 70 percent estimate for schizophrenia [2], the genomics era has proven those 19th century pioneers right, and has instilled much optimism with regard to genetic tests that can diagnose specific disorders and predict treatment responses to psychotropic substances and avoid side effects. Despite this, the use of precision health techniques in clinical psychiatry is currently quite limited, with the exception of Huntington's illness and 22q11 deletion syndrome. It is simple to attribute this to the polygenic and pleiotropic character of genetic contributions to mental disorder, given the hundreds of causative genetic variations that have been discovered so far and the thousands that are predicted to exist. There's still more. Because our genes do not appear to have read the DSM-IV or to particularly respect the diagnostic boundaries it established, as Kenneth Kendler famously put it: "Patterns of underling genetic liability do not map well onto current DSM [Diagnostic and Statistical Manual of Mental Disorders] categories." While the DSM has progressed to its fifth version [4] after that enlightening statement, it has been a constant problem to connect its myriad diseases with discoveries from genetic investigations, and the individualized approach has continued to be somewhat futuristic ideal in psychiatry. 

Damian Sendler

Damian Jacob Sendler: To be honest, this is really bad since psychiatry used to lead the way in individualized care long before the phrase was ever coined! When I was a student, there was a wealth of information in the medical literature around the beginning of the nineteenth century that could be applied to people with very particular symptoms and syndromes. In that pivotal time, I would have loved to be a doctor in order to peruse the newly printed scientific journals that described the exciting first descriptions of autoscopy [5], peduncular hallucinosis [6], Capgras' syndrome [7], Alzheimer's disease [8], dissociation [9], cryptomnesia [10], Riddoch's phenomenon [11], and many other symptoms, syndromes, and disorders, only a few of which eventually made it into the DSM. What occurred over the intervening decades to make us end up with diagnostic tools like as the DSM-5, which either bundle those unique clinical illnesses together into broad disease categories or fail to include them at all, given the extraordinary richness of that pioneering period? 

Dr. Sendler: That is a depressing question, and the solution is much more so. 19th-century psychiatry was more about controlling the behavior of groups of inpatients than generating fancy diagnoses because of the absence of particular treatment procedures. Men and women were separated in'men, unruly/women, unruly/women, unruly, quiet' layouts at asylums. With little motivation to concentrate on the complex discoveries reported in modern scientific publications, it's unsurprising that people just cared about whether they were required to get in and whether they could keep the door closed. The first age of customized medicine in psychiatry ended in a peaceful manner in this manner. 

What about those lofty views about heredity, you ask? A 19th century degeneration hypothesis based on 'damaged germ cells' that people were said to acquire via disease, addiction, and morally poor conduct was a fertile ground for the extinction of the family line in four generations [13] if it wasn't for this notion. As far back as people could remember, the concept of heredity conjured up images of dread and gloom rather than today's upbeat anticipations. 

Damian Jacob Sendler

The vast majority of newly developed disease concepts in the nineteenth century led to a sprawling nomenclature that may have worked for specialists, provided they kept up with the booming literature, but was not useful to those in administrative roles, such as hospital directors, insurers, and epidemiologists. When faced with such an overwhelming number of illness ideas, the New York Academy of Medicine launched a public awareness campaign for a comprehensive review of mental diseases that would address diagnostic as well as administrative concerns. In 1952, the Diagnostic and Statistical Manual: Mental Disorders [14] was published, the culmination of a 25-year effort. Classic textbooks of psychiatry were used to provide an overview of mental illness classifications. The terminology was also expected to be adopted throughout the country. 

It took six revisions to catch up to the original DSM, the most current of which (DSM-5) has no less than 947 pages in length. The ring binder, of course, had long since been retired. 

DSM's diagnostic categories have a high degree of reliability, and the manual has succeeded in imposing a consistent nomenclature not just in the United States, but across the globe as well. This means that the previous overabundance of illness words has been properly dealt with. However, the pearls of nosology they represented had been cleverly concealed. Consequently, psychiatrists must now construct more precise illness ideas to have their patients compensated by insurance companies, leaving a huge gap in diagnosis. With each each DSM edition, critics have accused the field of psychiatry of trying to pathologize more and more parts of daily life, while conversely, the DSMs give far too few options for a thorough diagnosis [15].

Damien Sendler: The American Psychiatric Association should consider including at least catatonia (a truly autonomous disease category), incubus phenomenon, clinical zoanthropy, attention deficit disorder psychosis, and a number of culture-bound syndromes that the DSM-5 mentions in passing, but which deserve to be developed into diagnostic categories ii. On top of that, I'd like to see a new chapter on hallucinatory syndromes, which would include distinct categories for musical hallucinations, sexual hallucinations, peduncular hallucinosis, and the Charles Bonnet syndrome, as well as a new chapter on the Alice in Wonderland syndrome, which would explicitly list the 60 or so different types of metamorphopsia and other perceptual distortions that can be experienced within its context [18]. 

So far, so good on my wish list. Because that's how we started off and where our prospects lay, those who assume that psychiatry would so intrude shamelessly on the area of neurology are accurate. Because how else can we make any progress in my profession if we don't fully explore how the brain works? It's still possible to take into consideration non-biological elements like social anxiety and sleep deprivation, which in the end have the same impact on mental diseases as the biological ones. An intriguing new study path is currently based on network theory, which enables us to characterize the effect on such components in scale-free, fully biopsychosocial models of illness, thereby transcending old boundaries between mind and body [19]. 

Damian Jacob Markiewicz Sendler: We now have the means to examine the underlying neurobiological and cognitive mechanisms of illness categories that our forefathers at the turn of the 20th century so skillfully characterized. When Kahlbaum initially conceived of catatonia in its contemporary form in 1874, it was thought to be extinct by the 1950s. Despite this, roughly 15% of all patients in acute mental nursing facilities are diagnosed with schizophrenia. Some 90% of these people may have been saved if the diagnosis had been made earlier. Catatonia deserves to be at the top of our categories for this reason alone. NMDA encephalitis has been linked to at least some catatonic states in recent investigations, while other studies have begun to identify the genetic risk for catatonia in various populations. 

Specific clinical syndromes, such as those reported during the age of classical psychiatry, have a significantly higher possibility of being related than the container categories found in the DSM, such as depression, anxiety, and schizophrenia. However, we should anticipate to see new diagnostic categories emerge as a result of disease-causing genetic variations in the near future. A clinical psychiatrist like myself is grateful for the opportunity to practice in such dynamic times, and I look forward to the day when my field integrates classical psychiatric principles with the latest genetic and neurological research to usher in the age of customized medicine 2.0.