NEW DELHI: A study has found a new biomarker of schizophrenia, which could also serve as a drug target for treating cognitive symptoms such as disorganised thinking or executive function.
Schizophrenia is a mental health disorder marked by an impaired ability to perceive and interpret reality and can involve delusions and disorganised thinking, or cognitive symptoms.
Researchers from the US' Northwestern University said that schizophrenia medications treat symptoms such as hallucinations and delusions, but do little for cognitive symptoms.
"A lot of people with schizophrenia cannot integrate well into society because of these cognitive deficits," author Peter Penzes, professor of neuroscience, pharmacology and psychiatry and behavioural sciences at Northwestern University's school of medicine, said.
"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," Penzes said.
The study, published in the journal 'Neuron', analysed the cerebrospinal fluid -- a clear liquid surrounding and protecting the brain and spinal cord -- of more than 100 schizophrenia patients and healthy people.
The researchers identified a previously unknown, freely circulating form of a brain protein called 'Cacna2d1' -- levels of the protein were reduced among patients with schizophrenia, compared to the healthy participants, resulting in overactive or overexcited brain circuits.
The team created a synthetic version of the protein, named 'SEAD1' and tested it in a mouse model of schizophrenia.
A single injection of SEAD1 into the animals' brains was found to correct both the abnormal brain activity and behavioural problems linked to the disorder, with few notable negative side effects.
While diseases such as diabetes or heart disease can be diagnosed by measuring biomarkers -- blood sugar or cholesterol -- diagnosing psychiatric disorders is much more subjective, Penzes said.
Further, many potential drugs don't perform well in clinical trials or later fail because of the diversity of people's biology, the researchers said.
The study pinpointed a specific schizophrenia biomarker, using which the scientists can identify a subgroup of people who would most likely respond well to this SEAD1-based peptide drug, they said.
"Our treatment reopens a crucial window to rewire connections in adult brains. The lack of brain plasticity is believed to be a key factor in the development of symptoms in schizophrenia. Reforming synapses could also be beneficial for other mental disorders, such as depression," first author Marc Dos Santos, research assistant professor of neuroscience at Northwestern University's school of medicine, said.
How long the therapeutic effects last is not known yet, but will be looked at in future experiments, the researchers said.