Does childhood maltreatment affect hikikomori via traits of modern-type depression?

BACKGROUND: In the 1990s, the concepts of hikikomori and modern-type depression (MTD) emerged in Japan. Hikikomori is a condition of social avoidance or isolation, characterized by staying at home and being physically isolated for at least six months. MTD is characterized by depressive symptoms-mainly in stressful work or school situations during adolescence and early adulthood-which tend to rapidly reduce or disappear after leaving the stressful situation. We hypothesized that childhood maltreatment can form MTD traits that lead to hikikomori. METHODS: As a first step, we conducted a multigroup path analysis between childhood maltreatment, MTD traits, and physical isolation in the hikikomori group. This study utilized the nine-item Patient Health Questionnaire (PHQ-9), Home Environment Questionnaire (HEQ), 22-item Tarumi Modern-Type Depressive Trait Scale (TACS-22), 25-item Hikikomori Questionnaire (HQ-25), and Hamilton Depression Rating Scale (HDRS). The HQ-25 contains three factors: physical isolation, lack of socialization, and lack of emotional support. RESULTS: The hikikomori group included 92 patients and the control group comprised 137 healthy individuals. All total and subscale scores of PHQ-9, HEQ, TACS-22, HQ-25, and HDRS were significantly higher in the hikikomori group than in the control group. The risk model of childhood maltreatment for physical isolation via MTD traits obtained good fit with a goodness-of-fit index of.982. LIMITATIONS: The study's limitations were its sample selection bias, cross-sectional design, and use of self-report scales. CONCLUSIONS: Our findings support the hypothesis that childhood maltreatment is an important risk factor for hikikomori via MTD traits.

ATP1A3 regulates protein synthesis for mitochondrial stability under heat stress.

Pathogenic variants in ATP1A3, the α3 subunit of the Na+/K+-ATPase-encoding gene, cause alternating hemiplegia of childhood (AHC) and related disorders. Impairments in Na+/K+-ATPase activity are associated with the clinical phenotype. However, it remains unclear whether additional mechanisms are involved in the exaggerating symptoms under stressed conditions in patients with AHC. We herein report that the intracellular loop (ICL) of ATP1A3 interacted with RNA-binding proteins, such as EIF4G, PABPC1 and FMRP. Both the siRNA-mediated depletion of Atp1a3 and ectopic expression of the p.R756C-variant ATP1A3-ICL in Neuro2a cells resulted in excessive phosphorylation of ribosomal protein S6 and increased susceptibility to heat stress. In agreement with these findings, iPSCs from a patient with the p.R756C variant were more vulnerable to heat stress than control iPSCs. Neurons established from the patient's iPSCs showed lower calcium influxes in responses to stimulation with ATP than controls. These data indicated that inefficient protein synthesis contributes to the progressive and deteriorating phenotypes of patients with the p.R756C variant among a variety of ATP1A3-related disorders.

Predominant affective temperaments in depressive patients with severe social withdrawal.

BACKGROUND: Hikikomori (HK) is characterized by self-isolation and social refusal, being more likely also associated with affective disorders, including depression. This case-control study primarily aimed at identifying (if any) predominant affective temperaments are associated with HK in depressed versus not-depressed individuals. Secondary objectives comprise assessing which other psychopathological dimensions (e.g., boredom, anxiety) are associated with the HK specifier in depressed individuals. METHODS: From the larger SWATCH study, 687 Italian young people were screened for depression, as measured by 9 items-Patient Health Questionnaire (PHQ-9) and HK-like social withdrawal, through the Hikikomori Questionnaire-25 (HQ-25). All subjects were administered a brief-Temperament Evaluation of Memphis, Pisa, Paris and San Diego (TEMPS-M), the 7 items-Generalized Anxiety Disorder (GAD-7) and the Multidimensional State Boredom Scale (MSBS). RESULTS: Males reported significantly higher scores at HQ-25 total score than females (p = 0.026). In the total sample, HK social withdrawal is positively predicted by MSBS low arousal, disengagement, depressive levels, depressive and irritable affective temperaments, while negatively by anxiety (F(6, 680) = 82.336, p < 0.001, R2 = 0.421). By selecting only depressed sample, HQ-25 is positively predicted by MSBS total score, low arousal and depressive affective temperament, while negatively by MSBS high arousal (F(4, 383) = 48.544, p < 0.001, R2 = 0.336). The logistic regression model found that the likelihood of developing depression with the HK specifier is significantly predicted by depressive and cyclothymic affective temperaments. CONCLUSIONS: These preliminary findings could help in clinically characterizing the relationship between specific affective temperamental profiles among individuals with depression with/without HK specifier, in order to provide a more tailored and personalized therapeutic approach. Our Italian study should be extensively replicated in larger, longitudinal and multicentric pan-European studies, by specifically assessing the impact of these findings on depression clinical course, prognosis and treatment outcomes.

Shifting the paradigm of social withdrawal: a new era of coexisting pathological and non-pathological hikikomori.

PURPOSE OF REVIEW: Social withdrawal syndrome, known as "hikikomori," has been highlighted since the late 1990 s in Japan. Hikikomori is more common in urban areas, and often comorbid with mental disorders, and now spreading throughout the world. In the post-COVID-19 era, not outing is no longer considered pathological in itself as the "new normal," and a novel concept of hikikomori is needed. This review summarizes the concept of hikikomori, and presents the latest methods for identification of hikikomori. RECENT FINDINGS: The novel definition can distinguish between pathological and non-pathological hikikomori using the scale of "Hikikomori Diagnostic Evaluation (HiDE)," which has been developed in the hikikomori research lab at Kyushu University. An online survey among non-working adults has revealed that persons who have become pathological hikikomori for less than three months showed a particularly strong tendency toward gaming disorder and depression. SUMMARY: Now, physical isolation itself is not pathological, but when dysfunction and distress are present, rapid mental health support should be provided. In the novel urban society, the establishment of a checkup system to assess whether persons who stay home are happy or suffering is important for prevention against mental disorders triggered by social isolation.

Could the Construct of Modern-Type Depression Predict Internet Gaming Disorder in Italian Video Gamers? A Case-Control Study.

A new postmodern depression type, named "Modern-Type Depression" (MTD), is emerging in Western countries. MTD is often underdiagnosed, mainly due to potentially higher comorbidity with technology-based addictions, including Internet Gaming Disorder (IGD). However, the definition of the relationship between MTD and IGD is still controversial, as few data have been published thus far. In particular, there are no data specifically investigating the prevalence of MTD within Italian young subjects with IGD, as well as their mutual association. Hence, within the SWATCH (Social Withdrawal and TeCno-mediated mental Health issues) project, our study aimed to identify the prevalence of MTD in a sample of Italian young adults who play video games by providing a clinical characterization of MTD within a group of IGD individuals (IGD+) versus a group without IGD (IGD-) who play video games. Our cross-sectional case-control study recruited a sample of 543 Italian young video-gaming players (aged 18-35) from the larger SWATCH database, stratified as IGD+ versus IGD-. Subjects were administered the 22-item Tarumi's Modern-Type Depression Trait Scale (TACS-22), the Motives for Online Gaming Questionnaire (MOGQ), and the Internet Gaming Disorder Scale-Short Form (IGDS9-SF). Around 21.7% of the total sample was represented by MTD individuals, while within the IGD sample, around 34% of subjects had MTD. Within the MTD group, significantly higher scores at IGDS-9SF (p < 0.001), MOGQ "Escape from reality" (p < 0.001), "Fantasy" (p < 0.001), and MOGQ total score (p = 0.003) were found compared to MTD-. According to the multivariate regression model, controlled for sex and age, higher scores in the TACS-22 were positively predicted by the total score of IGDS9-SF (p = 0.003), the MOGQ "Escape from Reality" subscale (p = 0.014), and MOGQ "Fantasy" (p = 0.011), and negatively predicted by the MOGQ "Competition" subscale (p = 0.035) [F (4538) = 17.265; p < 0.001]. Our findings suggested that MTD displays a strong association with IGD. Video-gaming players who do not have IGD appear to be less prone to MTD; this suggests that further studies could be carried out to specifically investigate whether pathological use of video games could also be determined by the presence of MTD.

Pharmacoepidemiology and Clinical Correlates of Lithium Treatment for Bipolar Disorder in Asia.

BACKGROUND: As clinical practices with lithium salts for patients diagnosed with bipolar disorder (BD) are poorly documented in Asia, we studied the prevalence and clinical correlates of lithium use there to support international comparisons. METHODS: We conducted a cross-sectional study of use and dosing of lithium salts for BD patients across 13 Asian sites and evaluated bivariate relationships of lithium treatment with clinical correlates followed by multivariate logistic regression modeling. RESULTS: In a total of 2139 BD participants (52.3% women) of mean age 42.4 years, lithium salts were prescribed in 27.3% of cases overall, varying among regions from 3.20% to 59.5%. Associated with lithium treatment were male sex, presence of euthymia or mild depression, and a history of seasonal mood change. Other mood stabilizers usually were given with lithium, often at relatively high doses. Lithium use was associated with newly emerging and dose-dependent risk of tremors as well as risk of hypothyroidism. We found no significant differences in rates of clinical remission or of suicidal behavior if treatment included lithium or not. CONCLUSIONS: Study findings clarify current prevalence, dosing, and clinical correlates of lithium treatment for BD in Asia. This information should support clinical decision-making regarding treatment of BD patients and international comparisons of therapeutic practices.

Development of depression assessment tools using humanoid robots -Can tele-operated robots talk with depressive persons like humans?

BACKGROUND: Depression is a common mental disorder and causes significant social loss. Early intervention for depression is important. Nonetheless, depressed patients tend to conceal their symptoms from others based on shame and stigma, thus hesitate to visit psychiatrists especially during early phase. We hypothesize that application of humanoid robots would be a novel solution. Depressed patients may feel more comfortable talking with such robots than humans. METHODS: We recruited 13 patients with major depressive disorder (MDD) and 27 healthy volunteers as controls. Participants took both tele-operated humanoid robot and human interviews to evaluate severity of depression using the Hamilton Depression Rating Scale (HDRS). In addition, participants completed a self-administered questionnaire asking about their impressions of the robot interview. RESULTS: Confidence interval and t-test analysis have revealed that the HDRS scores are equally reliable between robot and human interviews. No significant differences were observed between the two interviews regarding "nervousness about the interview" and "hesitancy to talk about depressed moods and suicidal ideation." Compared to human interviews, robot interviews yielded significantly lower scores on shame-related factors especially among patients with MDD. LIMITATION: Small sample size, and the evaluator is male only. CONCLUSIONS: This is the first report to show the reliability of tele-operated humanoid robot interviews for assessment of depression. Robot interviews are potentially equally reliable as human interviews. Robot interviews are suggested to be more appropriate in assessing shame-related suppressed emotions and hidden thoughts of depressed patients in clinical practice, which may reduce the stigma associated with depression.

TRPV4-mediated Ca2+ deregulation causes mitochondrial dysfunction via the AKT/α-synuclein pathway in dopaminergic neurons.

Mutations in the gene encoding the transient receptor potential vanilloid member 4 (TRPV4), a Ca2+ permeable nonselective cation channel, cause TRPV4-related disorders. TRPV4 is widely expressed in the brain; however, the pathogenesis underlying TRPV4-mediated Ca2+ deregulation in neurodevelopment remains unresolved and an effective therapeutic strategy remains to be established. These issues were addressed by isolating mutant dental pulp stem cells from a tooth donated by a child diagnosed with metatropic dysplasia with neurodevelopmental comorbidities caused by a gain-of-function TRPV4 mutation, c.1855C > T (p.L619F). The mutation was repaired using CRISPR/Cas9 to generate corrected isogenic stem cells. These stem cells were differentiated into dopaminergic neurons and the pharmacological effects of folic acid were examined. In mutant neurons, constitutively elevated cytosolic Ca2+ augmented AKT-mediated α-synuclein (α-syn) induction, resulting in mitochondrial Ca2+ accumulation and dysfunction. The TRPV4 antagonist, AKT inhibitor, or α-syn knockdown, normalizes the mitochondrial Ca2+ levels in mutant neurons, suggesting the importance of mutant TRPV4/Ca2+/AKT-induced α-syn in mitochondrial Ca2+ accumulation. Folic acid was effective in normalizing mitochondrial Ca2+ levels via the transcriptional repression of α-syn and improving mitochondrial reactive oxygen species levels, adenosine triphosphate synthesis, and neurite outgrowth of mutant neurons. This study provides new insights into the neuropathological mechanisms underlying TRPV4-related disorders and related therapeutic strategies.

Heterogeneity of gaming disorder: A clinically-based typology for developing personalized interventions.

Background: The eleventh revision of the International Classification of Diseases (ICD-11) defines the three key diagnostic criteria for gaming disorder (GD). These are loss of control over gaming, gaming as a priority over daily activities, and impaired functioning due to gaming. While this definition has implications for the prevention and treatment of GD, there is significant heterogeneity in the symptoms and etiology of GD among individuals, which results in different treatment needs. Cognitive control, emotional regulation, and reward sensitivity are three critical dimensions in the etiology model for GD. Aspects such as gender, comorbidity, motivation for gaming, stage or severity of GD, and risk factors all contribute to the heterogeneity of etiology among individuals with the disorder. Method: On the basis of clinical symptoms and comorbidity characteristics among approximately 400 patients with gaming disorder, the present paper proposes a clinical typology of patients with GD based on the authors' clinical experience in treating individuals with GD. Results: The findings indicated three common types of patients with GD: (i) impulsive male patients with attention deficit hyperactivity disorder (ADHD), (ii) dysphoria patients with dysfunctional coping skills, and (iii) isolated patients with social anxiety. The paper also discusses the presentation and treatment priority for these patients. Conclusion: Personalized treatments for patients with GD should be developed to fit their individual needs. Future studies should examine the heterogeneity of GD and confirm these types, as well as obtain evidence-based information that can help in the development of personalized treatment. Treatment resources should be developed, and professionals should be trained to provide integrated individualized treatment.

Analyzing changes in help-seeking from mental and physical health professionals during COVID-19 in Japan.

Japan witnessed the outbreak of coronavirus disease (COVID-19) in March - May 2020. We examined whether the impact of COVID-19 on people seeking help from mental and physical health professionals varied with changes in employment (from full-time employment to unemployment or leave of absence) and psychological predisposition to new-type depression (Interpersonal Sensitivity [IS]/Privileged Self [PS]) associated with the pandemic. An online survey was conducted in June 2020 (after the outbreak of COVID-19) among people who were full-time employees as of April 2019. Data from 1,053 individuals were analyzed. The survey asked about regular visits to health professionals one year prior to the survey (June 2019) and at the time of the survey. Employment status, personality traits, and demographic characteristics were also examined. We found that consultation rates changed little before and after the pandemic. Logistic regression analysis showed that after controlling for age and gender, being unemployed or absent from work after the pandemic and having higher scores for IS/PS were positively associated with regular visits to health professionals. Considering that COVID-19 has been shown to increase the incidence of physical and mental illness, the finding that the rate of consultations remained unchanged implies that consultations were withheld. Joblessness/absence from work and IS/PS had negative effects on physical and mental health, leading to fewer visits.

Effects of melatonin on dopaminergic neuron development via IP3-mediated mitochondrial Ca2+ regulation in autism spectrum disorder.

Melatonin entrainment of suprachiasmatic nucleus-regulating circadian rhythms is mediated by MT1 and MT2 receptors. Melatonin also has neuroprotective and mitochondrial activating effects, suggesting it may affect neurodevelopment. We studied melatonin's pharmacological effects on autism spectrum disorder (ASD) neuropathology. Deciduous tooth-derived stem cells from children with ASD were used to model neurodevelopmental defects and differentiated into dopaminergic neurons (ASD-DNs) with or without melatonin. Without melatonin, ASD-DNs had reduced neurite outgrowth, mitochondrial dysfunction, lower mitochondrial Ca2+ levels, and Ca2+ accumulation in the endoplasmic reticulum (ER) compared to control DNs from typically developing children-derived stem cells. Melatonin enhanced IP3-dependent Ca2+ release from ER to mitochondria, improving mitochondrial function and neurite outgrowth in ASD-DNs. Luzindole, an MT1/MT2 antagonist, blocked these effects. Thus, melatonin supplementation may improve dopaminergic system development in ASD by modulating mitochondrial Ca2+ homeostasis via MT1/MT2 receptors.

Heterogeneity and mitochondrial vulnerability configurate the divergent immunoreactivity of human induced microglia-like cells.

Microglia play versatile roles in progression of and protection against neuroinflammatory diseases. Little is known, however, about the mechanisms underlying the diverse reactivity of microglia to inflammatory conditions. We investigated how human induced microglia-like (iMG) cells respond to innate immune ligands. Quantitative PCR showed that poly-I:C and lipopolysaccharide (LPS) activated the expression of IL1B and TNF. Immunoreactivity of iMG did not differ between controls (n = 11) and patients with neuroinflammatory diseases (n = 24). Flow cytometry revealed that CD14high cells expressed interleukin (IL) -1ß after LPS treatment. Immunoblotting showed that poly-I:C and LPS differentially activated inflammatory pathways but commonly induced mitochondrial instability and the expression of pyruvate kinase isoform M2 (PKM2). Furthermore, a potent stimulator of PKM2 (DASA-58) alleviated IL-1ß production after LPS treatment. These data indicate that heterogeneous cell populations and mitochondrial stability underlie the divergent immunoreactivity of human iMG in environments.

Angiogenic and inflammatory responses in human induced microglia-like (iMG) cells from patients with Moyamoya disease.

Angiogenic factors associated with Moyamoya disease (MMD) are overexpressed in M2 polarized microglia in ischemic stroke, suggesting that microglia may be involved in the pathophysiology of MMD; however, existing approaches are not applicable to explore this hypothesis. Herein we applied blood induced microglial-like (iMG) cells. We recruited 25 adult patients with MMD and 24 healthy volunteers. Patients with MMD were subdivided into progressive (N = 7) or stable (N = 18) group whether novel symptoms or radiographic advancement of Suzuki stage within 1 year was observed or not. We produced 3 types of iMG cells; resting, M1-, and M2-induced cells from monocytes, then RNA sequencing followed by GO and KEGG pathway enrichment analysis and qPCR assay were performed. RNA sequencing of M2-induced iMG cells revealed that 600 genes were significantly upregulated (338) or downregulated (262) in patients with MMD. Inflammation and immune-related factors and angiogenesis-related factors were specifically associated with MMD in GO analysis. qPCR for MMP9, VEGFA, and TGFB1 expression validated these findings. This study is the first to demonstrate that M2 microglia may be involved in the angiogenic process of MMD. The iMG technique provides a promising approach to explore the bioactivity of microglia in cerebrovascular diseases.

Ameliorative effects of Fingolimod (FTY720) on microglial activation and psychosis-related behavior in short term cuprizone exposed mice.

Schizophrenia is a psychiatric disorder that affects around 1% of the population in widespread populations, with severe cases leading to long-term hospitalization and necessitation of lifelong treatment. Recent studies on schizophrenia have highlighted the involvement of inflammatory and immunoregulatory mechanisms with the onset of symptoms, and the usage of anti-inflammatory treatments are being tested against periods of rapid psychosis. In the central nervous system, microglia are the innate immune population which are activated in response to a wide range of physical and psychological stress factors and produce proinflammatory mediators such as cytokines. Microglial activation and neuroinflammation has been associated to numerous psychiatric disorders including schizophrenia, especially during psychotic episodes. Thus, novel treatments which dampen microglial activation may be of great relevance in the treatment of psychiatric disorders. Fingolimod (FTY720) is a drug used as an immunosuppressive treatment to multiple sclerosis. Recent clinical trials have focused on FTY720 as a treatment for the behavioral symptoms in schizophrenia. However, the mechanisms of Fingolimod in treating the symptoms of schizophrenia are not clear. In this study we use a recently developed neuroinflammatory psychosis model in mice: cuprizone short-term exposure, to investigate the effects of FTY720 administration. FTY720 administration was able to completely alleviate methamphetamine hypersensitivity caused by cuprizone exposure. Moreover, administration of FTY720 improved multiple measures of neuroinflammation (microglial activation, cytokine production, and leucocyte infiltration). In conclusion, our results highlight the future use of FTY720 as a direct anti-inflammatory treatment against microglial activation and psychosis.

Hikikomori: A perspective from bibliometric analysis.

AIMS: Hikikomori is a common phenomenon reported in Japan and many other countries. However, the broad trends of the research publications on hikikomori are unclear. Therefore, this study examined the patterns of research on hikikomori using bibliometric analysis. METHODS: Relevant publications were searched in Web of Science. Bibliometric analyses were performed with CiteSpace, R and VOSviewer. RESULTS: In total, 297 publications on hikikomori met the eligibility criteria. The International Journal of Social Psychiatry (IF = 10.461) published the most papers (K = 17, or 5.7%) on hikikomori. Takahiro A. Kato from Kyushu University (41; 13.8%; H-index = 18) was the most influential author, while Takahiro A. Kato (total link strength [TLS]: 235), Alan R. Teo (TLS: 157), and Masaru Tateno (TLS: 153) separately had the strongest research collaboration with other researchers. Of all countries that published on hikikomori, Japan had the highest number of publications (K = 91). The keywords "United States" and "psychiatric diagnosis" received the most attention between 2013 and 2015, whereas "health" and "autism spectrum disorder" received the most attention in 2021 and 2022. CONCLUSIONS: Peer-reviewed research publications on hikikomori are growing rapidly and the research trends in this field are also changing.