Autism: Bromide Ions Promising Research?

700,000 French affected by autism spectrum disorders (ASD). Almost the same number received ideas and theories about their origin. Hundreds of research studies… Could a new one, carried out by researchers from Inserm, CNRS, Inrae* and the University of Tours, change the situation? It reveals the promising results of a molecule commonly used in the treatment of epilepsy: bromide ions. Preclinical studies in mice have shown a restoration of social skills, as well as a reduction in anxiety and stereotyped behaviors. This therapeutic route considered “promising” was published in April 2022 in the international scientific journal Neuropsychopharmacology (excerpt in English via the link below)… Obviously it is about ” to relieve “ certain symptoms and ” look after “ autism.

Epilepsy, common comorbidity

“With the arrival on the market of new drugs for epileptic patients, their use has decreased but it continues to be an interesting therapeutic tool, especially in cases of epilepsy resistant to conventional treatments”, indicates Inserm during a press conference on June 16, 2022. Epilepsy is a common comorbidity in people with autism, so it is likely that certain risk factors and pathophysiological processes are common. This is the hypothesis that led scientists to study more specifically the efficacy of bromide ions in the context of TEAs.

dysfunctional neural connections

In the brain, maintaining a balance between the phenomena of excitation and inhibition in neuronal circuits is essential for its proper functioning throughout life. Therefore, imbalances can cause many disorders, especially epilepsy. Similarly, some forms of ASD have been associated with dysfunction of inhibitory neural connections., specifies Insert. In the case of epilepsy, bromide ions help correct this imbalance by promoting inhibition, thus preventing seizures. Therefore, scientists believed that a similar effect could be expected for ASDs, with visible clinical impact on social and stereotyped behaviors… Rightly so!

Success in 3 different genetic mutations

After testing this treatment on three mice that also had different genetic mutations responsible for the autistic phenotype, the team observed beneficial effects on the social aspect. These conclusions, observed in three different models, insists Inserm, “It allows us to be a little more confident about the treatment’s ability to be generalizable to various subgroups of autistic individuals in future clinical trials,” Jérôme Becker, a researcher at Inserm, and Julie Le Merrer, a researcher at the CNRS, co-authors of the study, stand out. Human testing is precisely the next step. “A big challenge”, according to Julie Le Merrer, who brings up the idea of ​​offering an oral treatment with drops, easier to take, especially for children.

Three other abandoned tracks

But, “Until now, autism research has not been very successful, so these early results are no guarantee of success.” she shades In recent years, advances in neuroscience and the identification of genetic or environmental risk factors have made it possible to better understand ASDs, but their causes are still poorly understood. In this context, therapeutic research advances with difficulty. Remember that three clinical trials have recently been abandoned, “due to results considered inconclusive, while the molecules initially studied had generated much hope”, agrees Inserm. The first study focused on a molecule called balovaptan intended to act on the socialization and communication skills of adults with ASD. In the second trial, children and adolescents received intranasal oxytocin, but this treatment had no significant impact on social interactions and cognitive functioning in the treated group. Finally, the third on a molecule called bumetanide (an antagonist of the chloride ion transporter NKCC1) showed no improvement in social behavior but only a reduction in stereotypies. With bromide ions, is new hope possible?

* National Institute of Health and Medical Research, National Center for Scientific Research and National Institute of Agrifood and Environmental Research