Stanford Medicine scientists are generating a periodic table of sorts for psychiatric disorders, providing better understanding of these conditions and paving the way toward targeted treatment.

By combining two massive, publicly available databases — one flagging genes associated with psychiatric disorders, the other showing which cells in which parts of the human brain are making the most use of which of our genes — they’ve implicated certain cell types, located in particular brain regions, in schizophrenia.

Like the periodic table of elements, which has enabled generations of scientists to predict the existence of yet-undiscovered elements and the behavior of those already known, the brain-cell classification system is the product of two sets of observations. In the former, the breakthrough stemmed from organizing the elements in a two-dimensional grid, presenting them not just in order of how many resident protons their atoms housed but also according to their chemical properties. The latter likewise combines two separate series of observations, yielding both confirmations of imaging- and autopsy-derived findings and unearthing previously unsuspected types of cells, in specific brain regions, that may be participants in the pathology of psychiatric disorders.

A study detailing these findings — the first of its kind to rely on fully human data throughout — was published Jan. 20 in Nature Neuroscience.

The still-experimental combinatorial method reveals a new way to learn about psychiatric disorders in general, said the study’s senior author, Laramie Duncan, PhD, assistant professor of psychiatry and behavioral sciences.

A periodic table for cells

The new study confirms many previous findings, from imaging and post-mortem tissue analyses, regarding places in the brain housing structures that are suspiciously small or where nerve-cell signaling appears disrupted in schizophrenia. It also implicates new brain-cell types schizophrenia researchers have not previously focused on. And it has unearthed brain-cell types, in key brain structures, that are common to psychiatric disorders beyond schizophrenia.

“Psychiatric disorders are mysterious, even though they impact at least one-fifth of the population at any given time,” Duncan said. Yet the pace of developing treatments for psychiatric disorders has been extremely slow.

“That’s partly because these disorders are so complex,” she said. “But it’s also because we don’t have a good neurobiological understanding of what’s causing them. A key step forward in understanding why people develop these disorders is to identify some of the precise cell types in the brain that contribute to them.”

Knowing that a particular kind of a cell is involved in a psychiatric disorder, plus knowing how that cell normally works and where it resides, provides a clue as to how that cell type’s dysfunction may be contributing to the disorder. Because the receptors on or in many cell types are known, it also zeroes in on what kind of drugs might work for schizophrenia.

That’s easy to say. But the brain is hard to study. Sampling cells deep in that organ typically requires an autopsy, not a biopsy. In contrast, the method the scientists used is noninvasive: It requires computation, not a surgical operation or even imaging.

The researchers focused primarily on schizophrenia because it’s a serious disorder found worldwide (about 0.5% of all individuals); genes account for roughly 70% to 80% of the variability in people’s likelihood of developing schizophrenia, the biggest genetic contribution of any psychiatric disorder; and it’s more reliably diagnosed than other disorders.

“Schizophrenia is the quintessential psychiatric disorder,” Duncan said. It’s marked by hallucinations (people see or hear things others don’t), delusions (believe themselves to be someone else, often someone famous) and profound difficulties in accomplishing daily activities.

It’s devastating. “For many, the symptoms are so severe that people with schizophrenia end up sleeping on the streets,” Duncan said.

Source: https://med.stanford.edu/news/all-news/2025/01/brain-cell--periodic-table--for-psychiatric-disorders-reveals-ne.html