Researchers at Seoul National University Bundang Hospital have published the world's first research on aripiprazole's, a conventional schizophrenia treatment, dopamine receptor occupancy rate, and its correlation with the working memory of schizophrenia patients.
Aripiprazole is an antipsychotic drug that acts differently depending on the patient's state of dopamine secretion. Schizophrenia is a mental illness which excessively produces dopamine, a neurotransmitter in the brain. The disease can cause hallucinations, abnormal behavior, memory and cognitive dysfunction.
Until now, conventional medications only blocked dopamine receptors inside the inner neurons to prevent dopamine from acting.
Aripiprazole, however, not only inhibits excessive dopamine production but also takes its place after occupying dopamine receptors to suppress its mechanism. The medication also improves benign symptoms such as hallucinations and delusions, while also treating negative symptoms. Such mechanism of the drug has allowed the treatment to receive attention as a third-generation antipsychotic drug.
The team, led by Professors Kim Eui-tae and Kwon Jun-soo of the department of psychiatry at the hospital, aimed to demonstrate that the drug can directly enhance working memory by measuring the aripiprazole’s binding capacity on dopamine receptors in patients with schizophrenia.
There were cases in which the patient's cognitive function improved after the administration of aripiprazole, but there have been no researches into whether the cognitive function enhanced because of the treatment of the aripiprazole or if the cognitive function of the patient improved as other symptoms got better. Also, conflicting clinical findings that showed antipsychotic drugs could enhance psychosis symptoms and decrease cognitive functions confused the research field.
Results showed that as the proportion of aripiprazole occupying dopamine receptors increased, the error rate of tasks requiring memory and the average response time decreased.
“Although there have been debates about the efficacy of aripiprazole, we have finally proved for the first time that this aripiprazole can improve the cognitive function of patients with schizophrenia by using a high-tech Raclopride PET test,” Professor Kim said. “With the result of the study, we will be able to reduce the confusion about clinical treatment policy in clinical trials related to schizophrenia.”
Kim went on to say, “We are also happy as we could develop a customized treatment strategy to restore cognitive function, which is essential for schizophrenia patients.”
Translational Psychiatry published the result of the study.