Researchers have identified a biomarker linked to schizophrenia that could lead to new treatments to tackle symptoms of the debilitating mental disorder not addressed by current medicines.

Currently available antipsychotic drugs can help to control a patient's hallucinations and delusions but they don't improve cognitive issues like disorganized thinking and executive dysfunction, which can often prevent individuals from living independently.

“A lot of people with schizophrenia cannot integrate well into society because of these cognitive deficits,” study leader Peter Penzes of Northwestern University Feinberg School of Medicine in Chicago said in a statement.

Analyzing cerebrospinal fluid samples from over 100 people with and without schizophrenia, researchers found those with the disorder had significantly lower levels of a brain protein called CACNA2D1 compared to healthy individuals, resulting in an overstimulation of the brain’s electrical networks that may contribute to cognitive symptoms.

The researchers created a synthetic version of the protein and tested it in a mouse model of genetic schizophrenia. A single injection into the animals’ brains corrected both the abnormal brain circuit activity and the behavioral problems linked to the disorder, without negative side effects such as sedation or reduced movement, they reported in Neuron.

“Our discovery could solve these challenges by establishing the basis of a revolutionary and completely novel treatment strategy through a tandem biomarker-peptide therapeutic approach,” added Penzes.

“The next step... would be to identify the (human) patients who could respond and treat them accordingly,” Penzes said.