Researchers discover numerous important biomarkers in folks with Hikikomori (pathological social withdrawal), and they exhibit their opportunity for predicting the severity of the condition.
Crucial blood biomarkers for the pathological social withdrawal condition called Hikikomori have been identified by scientists at Kyushu College. The team’s exploration enabled them to distinguish amongst healthy folks and hikikomori victims, as effectively as to gauge the severity of the sickness.
Hikikomori is a ailment in which folks isolate them selves from society and spouse and children for a time longer than six months, according to the Ministry of Wellbeing, Labour, and Welfare of Japan. Hikikomori, also identified as “pathological social withdrawal,” is reported to impact more than a million individuals in Japan as of 2022. While it has usually been considered of as a syndrome unique to the Japanese culture, evidence about the earlier couple of a long time has shown that it is increasingly turning out to be a world phenomenon. Some fear that the
In a report published in Dialogues in Clinical Neuroscience, lead researcher Takahiro A. Kato of Kyushu University’s Faculty of Medical Sciences explains that while the sociological underpinnings of the condition are carefully studied, major gaps remain in the understanding of the biological aspects of hikikomori.
“Mental illnesses such as depression, schizophrenia, and social anxiety disorder are occasionally observed in hikikomori individuals. However, our past research shows that it is not that simple, and that it is a complex condition with overlaps of different psychiatric and non-psychiatric elements,” explains Kato. “Understanding what happens biologically will help us greatly in identifying and treating hikikomori.”
The team conducted blood biochemical tests and collected data on the plasma metabolome—small molecules found in the blood such as sugars, amino acids, and proteins—from 42 unmedicated hikikomori individuals and compared it with data from 41 healthy volunteers. In total, data for 127 molecules were analyzed.
“Some of our key findings showed that in the blood of men with hikikomori, ornithine levels, and serum arginase activity were higher while bilirubin and arginine levels were lower,” states first author of the paper Daiki Setoyama. “In both men and women patients, long-chain acylcarnitine levels were higher. Moreover, when this data was further analyzed and categorized, we were able to distinguish between healthy and hikikomori individuals, and even predict its severity.”
Ornithine is an amino acid produced from the amino acid arginine with the help of the enzyme arginase. These molecules are vital in many bodily functions, including blood pressure regulation and the urea cycle.
Bilirubin is made when the liver breaks down red blood cells and is often used as a marker for proper liver function. Patients with major depression and seasonal affective disorder have been reported to have lower blood bilirubin levels.
Finally, acylcarnitines play an important role in supplying energy to the brain. Its levels decrease when patients with depression take selective serotonin reuptake inhibitors. However, patients with hikikomori differ from patients with depression in that only the long-chain acylcarnitines are elevated in hikikomori whereas short-chain acylcarnitines remain the same.
Says Kato, “Identifying the biomarkers of hikikomori is the first step in uncovering the biological roots of the condition and connecting them to its severity. We hope these findings will lead to better-specialized treatments and support for hikikomori.”
“Many questions remain, including understanding the root causes behind these biomarkers. Today, hikikomori is spreading worldwide, thus, we must conduct international investigations to understand the similarities and differences between patients with hikikomori globally,” he concludes.
Reference: “Blood metabolic signatures of hikikomori, pathological social withdrawal” by Daiki Setoyamaa, Toshio Matsushima, Kohei Hayakawa, Tomohiro Nakao, Shigenobu Kanba, Dongchon Kang and Takahiro A. Kato, 1 June 2022, Dialogues in Clinical Neuroscience.
The study was funded by the Japan Society for the Promotion of Science and the Japan Agency for Medical Research and Development.