A local study raised the possibility that physicians can pick and choose the right medicine for schizophrenia patients by predicting their antipsychotic responsiveness.

Professor Kim Eui-tae at Neuropsychiatry Department of Seoul National University Bundang Hospital and Professor Kwon Jun-soo at Neuropsychiatry Department of Seoul National University said their study was published on the latest issue of Psychological Medicine, a medical journal.

Schizophrenia patients are divided into two groups – those with the “treatment-response schizophrenia” who respond to the first-line antipsychotic drug and the others with “treatment-resistant schizophrenia” who fail with the drug but respond to clozapine only.

Unless physicians try out the first-line antipsychotic drug, they cannot know whether the patient is the former or the latter case. If the patient has treatment-resistant schizophrenia, the treatment time is delayed.

The research team has been conducting a related study to find a way to provide tailored treatment by predicting treatment responsiveness in advance.

In 2017, the researchers found that the treatment-resistant group produced less dopamine by more than 10 percent than the treatment-response group.

This time, they discovered the pathophysiology difference based on the correlation between brain functional connectivity and dopamine production. In other words, the study signals that physicians can choose the treatment before administering the first-line antipsychotic drug.

The researchers recruited 12 treatment-response patients, 12 treatment-resistant patients, and 12 healthy volunteers. Then, they measured brain connectivity through functional magnetic resonance imaging (MRI) and presynaptic dopamine production through DOPA PET (dihydroxyphenylalanine positron emission tomography) scans.

The result showed that in patients with the treatment-response schizophrenia, the functional connectivity of the brain was negatively correlated with presynaptic dopamine production.

In the treatment-resistant group, there was no such correlation. It indicates that schizophrenia patients’ pathophysiology could be different depending on their responsiveness to the antipsychotic drug, the researchers said.

“The study was the world’s first to find pathophysiology of schizophrenia by applying functional MRI and DOPA PET scans simultaneously,” Kim said. “I expect that the study will enable customized treatment for schizophrenia patients and set a milestone for research of cause for schizophrenia and treatment development.”