Dr. Chaumetteâs fascination with the mysteries of the human mind was what made him choose psychiatry, and not neurology, as his specialty. The psychiatrist, who is an adjunct professor in the Department of Psychiatry at Ïăœ¶ÊÓÆ” and a researcher at the Institut de psychiatrie et neurosciences de âŻParis, has been making one discovery after another ever since. Â
The MD/PhDâs slightly obscure field of study, genetic psychiatry, is revolutionizing our understanding of mental illness. âTraditionally, psychiatrists made their diagnoses based on symptoms a patient expressed, but now we can use biology and genetics to explain certain disorders.âÂThe researcher and clinician, who works in Paris at the HĂŽpital Sainte-Anneâthe unofficial name of the GHUâŻParis Psychiatrie et Neurosciencesâjust published a new work written for a general audience, (Schizophrenia and genetics: the DNA of madness?) [HumenSciences, 2024]. Though its title is slightly provocative, this enlightening book explains the latest advances in genetic psychiatry and how these are raising hopes for better treatments. Â
âMy biggest surprise, as a psychiatrist, is to see how much we are helping families. When I first started studying genetic psychiatry, I was a bit worried that families would reject these new notions. But the opposite is true. Families spontaneously come to us to find out whatâs going on.âÂ
Families have been victims of prejudice for far too long, says Chaumette. âThere was a perception that mothers had raised their child badly, or not given them enough affection. Mothers were always blamed, but never fathers. My book says, âSchizophrenia is a biological illness, itâs not your fault.â It takes the guilt off families and friends.âÂ
Genetic psychiatry will not make gene therapy possible, but it does explain the many forms schizophrenia can take. The field is revolutionizing thinking about psychiatry and sparking controversy, particularly in France, where psychoanalysis has long had a stronghold.
âPsychiatry has always treated the soul in a disembodied way, but genetics tells us that the soul is embedded in matter. Not everyone is open to that.âÂ
Genetics creates both hopes and illusions about treatmentâincluding a form of determinism that says, âIf itâs genetic, nothing can be done about it.â But Chaumette says the opposite is true. âIn the case of certain defects in a specific gene, we can say that 50% of people affected will develop schizophrenia. But itâs not an either/or situation. There is no guarantee.â Rather, the information provided by genetics makes it possible to avoid environmental risk factors, such as cannabis use and childhood stress, both major triggers, he explains. This knowledge also offers tools the patientâs support network can use to detect early symptoms. That, in turn, increases the effectiveness of treatment. âJust being informed is liberating.âÂ
In his book, the researcher shares a telling statistic about the degree of acceptance and resistance to genetic psychiatry. Half the patients in his referral centre come on their own or on the advice of a relative or association. Only 20% are referred by a psychiatrist. âAs with AIDS and cancer, itâs the patients, their families and associations that are moving things forward. The people who are most apprehensive about genetic psychiatry are psychiatrists themselves, who are not comfortable with these issues. But Iâm hopeful because young people graduating from university today are more aware of the biological factors that cause illness.âÂ
Dusting off old ideasÂ
Even if he had chosen another medical specialty, the 39-year-old psychiatrist thinks his personality would have eventually pushed him towards genetics. âMedically and intellectually, itâs absolutely fascinating,â he says. âItâs like detective work, where you use tests and observations to understand things.â Â
One of the main reasons Chaumette chose McGill for his postdoctoral studies in 2016â2018 was that research on genetic psychiatry was much more developed here than in his native France. As a member of a team led by Dr. Guy Rouleau, Director of The Neuro (Montreal Neurological Institute-Hospital) and a pioneer in neurogenetics, Chaumette was able to move forward in his work thanks to the availability of data on childhood schizophrenia. Â
Born in Ăvreux, Normandy, Chaumette returned to live in his native country but kept his ties with McGill. âTwo or three years ago, I would have told you that my discipline was underdeveloped in France, but the pandemic triggered an epidemic of poorly treated mental illnesses. The French government has been playing catch-up ever since and research budgets are increasing in pace with that.âÂ
Knowledge about genetic psychiatry is rapidly advancing, but the field is still in its infancy. âWe can now provide advice, make recommendations for prevention and adapt care. For certain specific genetic defects, we can establish a fairly precise probability of the disorder occurring. However, when schizophrenia is polygenic, meaning that it involves several genes, genetics can only tell us what is going on in a group of patients. Itâs not yet useful for treating individuals.âÂ
The greatest promise of genetic psychiatry now lies in pharmacogenetics, says the researcher. âTraditionally psychiatrists determine treatment and dosage through trial and error, but that wastes a lot of time. We are starting to be able to use genetics to explain how a patient metabolizes certain drugs. A new strategy called precision psychiatry is emerging, where genetics can be used to establish the best drug and the best dosage for an individual. Itâs still in the future, but thatâs where weâre headed.âÂ
Genetic psychiatry has also stirred interest from pharmaceutical companies, who had been losing interest in psychiatry. âWe had dopamine treatments that were more or less effective. But research has now identified other neurotransmitters, so we are entering a new phase of therapeutic and clinical trials.âÂ
When ethics meets geneticsÂ
Chaumette is interested in schizophrenia, in particular, because of what it says about human consciousness.
âSome brain diseases, such as Parkinsonâs or multiple sclerosis, are very organic. But schizophrenia combines the purely organic with the human essence, our consciousness. There is something organic going on that modifies consciousness.âÂ
Even though he has devoted his career to introducing âhardâ science into a field considered scientifically âsoft,â as he puts it, Chaumette insists that research must not take precedence over psychosocial rehabilitation. âFirstly, genes donât explain everything. Also, once a person is ill, we need to find the best therapy possible to improve their day-to-day autonomy.â Â
For this researcher fascinated by the mind, genetics quickly raises ethical questions. Chaumette believes that marketing genetic tests without professional guidance, a practice carried out in North America, is harmful. The practice is prohibited in Europe, where doubts have been raised about its merits. âGenetic tests are always difficult to interpret. People get so anxious they become sick, and then the test becomes a self-fulfilling prophecy.â Â
Chaumette also opposes carrying out systematic screening, for ethical reasons. âWhatâs the point of screening if thereâs no treatment? And what can we do, apart from worry, while we wait for the disease to developâif it even does develop? Could this be misused by insurers or money lenders? If someone is at risk, should we consider terminating their pregnancy? Given the current state of knowledge, I donât think large-scale screening is ethical. What is ethical is working to understand why a person develops symptoms in the first place.âÂ
This article is a translation of the original French, Les mystĂšres de l'esprit.