Avoidant personality disorder and taijin kyoufu: sociocultural implications of the WHO/ADAMHA International Study of Personality Disorders in Japan

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.

Estimating the prevalence and characteristics of people in severe social isolation in 29 European countries: A secondary analysis of data from the European Social Survey round 9 (2018-2020)

The main aim of the present study was to estimate the prevalence of people in severe social isolation as a proxy for high risk of hikikomori using data from 29 European countries. The relationship between the presence/absence of severe social isolation and demographic and psychosocial variables was also investigated. Publicly available data from the European Social Survey (ESS) round 9 collected between August 2018 and January 2020 were used. Data from the ESS round 1 (September 2002 -December 2003) and round 10 (September 2020 -May 2022) were also examined to investigate changes in the prevalence of severe social isolation over time. Analyses were restricted to the working-age population (15-64 years). A complex sampling design to obtain weighted prevalence and results was used. The study protocol was preregistered online on the Open Science Framework (https://osf.io/6a7br/). The weighted prevalence of severe social isolation was 2.01% for the sample from the ESS 1, 1.77% for the sample from the ESS 9, and 1.71% for the sample from the ESS 10, indicating a decrease over time, mainly in males. Logistic regression models showed that different sociodemographic factors (e.g., being retired, being permanently sick or disabled, doing housework, living in Central and Eastern Europe, living uncomfortably on household income, having no income) were associated with severe social isolation. Further, feeling unsafe when walking alone in the neighbourhood after dark, low social trust, and support, decreased happiness and lack of future planning correlated with severe social isolation after adjustment for the effect of sociodemographic factors was made. In this study, the prevalence of severe social isolation as a proxy for hikikomori in European countries is in line with that found by previous representative studies conducted in Asian countries. The novelty of the findings as well as implications for hikikomori research are discussed according to recent scientific literature.

Jiko-shisen-kyofu (fear of one's own glance), but not taijin-kyofusho (fear of interpersonal relations), is an east Asian culture-related specific syndrome

OBJECTIVE

According to the DSM-IV-TR, the concept of taijin-kyofusho (fear of interpersonal relations) is both unique to East Asia and a culture-bound syndrome. In the indigenous diagnostic classification system in Japan, taijin-kyofusho consists of four subtypes, i.e. sekimen-kyofu (phobia of blushing), shubo-kyofu (phobia of a deformed face/body), jiko-shu-kyofu (phobia of one's own foul body odour), and jiko-shisen-kyofu (phobia of one's own glance). Each subtype except for phobia of one's own glance can be adequately assigned to a respective existing category in the DSM-IV-TR. The aim of the study was to introduce clinical features of phobia of one's own glance to western psychiatrists.

METHODS

Description of a series of cases with jiko-shisen-kyofu (phobia of one's own glance).

RESULTS

All of our cases shared the unique feature that they suffered from the preoccupation that their own glance was offensive to others, and as a result were socially withdrawn themselves.

CONCLUSIONS

To our best knowledge, no cases with a clear picture of phobia of one's own glance have been reported in the West to date. The controversial issue of the classification of phobia of one's own glance as an east Asian culture-related specific syndrome was addressed.

Social anxiety disorder: questions and answers for the DSM-V

BACKGROUND

This review evaluates the DSM-IV criteria of social anxiety disorder (SAD), with a focus on the generalized specifier and alternative specifiers, the considerable overlap between the DSM-IV diagnostic criteria for SAD and avoidant personality disorder, and developmental issues.

METHOD

A literature review was conducted, using the validators provided by the DSM-V Spectrum Study Group. This review presents a number of options and preliminary recommendations to be considered for DSM-V.

RESULTS/CONCLUSIONS

Little supporting evidence was found for the current specifier, generalized SAD. Rather, the symptoms of individuals with SAD appear to fall along a continuum of severity based on the number of fears. Available evidence suggested the utility of a specifier indicating a "predominantly performance" variety of SAD. A specifier based on "fear of showing anxiety symptoms" (e.g., blushing) was considered. However, a tendency to show anxiety symptoms is a core fear in SAD, similar to acting or appearing in a certain way. More research is needed before considering subtyping SAD based on core fears. SAD was found to be a valid diagnosis in children and adolescents. Selective mutism could be considered in part as a young child's avoidance response to social fears. Pervasive test anxiety may belong not only to SAD, but also to generalized anxiety disorder. The data are equivocal regarding whether to consider avoidant personality disorder simply a severe form of SAD. Secondary data analyses, field trials, and validity tests are needed to investigate the recommendations and options.

Human personality traits are associated with individual environmental traits in male adolescents--a pilot study

The human personality seems to be formed by biological (internal) and environmental (external) factors, which function interactively. This pilot study examined the relationship between fundamental personality traits and individual environmental traits in healthy adolescents. A complex relationship between personality traits and candidate environmental traits was found in this sample. Parental smoking, one of the hypothetical environmental traits, was significantly associated with the sociability personality trait of adolescent offspring. Another hypothetical environmental trait-parent/child attachment status-"was related to novelty-seeking personality. Unexpectedly, these associations were observed only in male but not in female adolescents. The present study suggested that (1) parental smoking behavior might directly or indirectly affect offspring social behavior and related personality by nongenetic transmission; (2) past and present data indicated that the triad of a poor parent/child relationship, novelty-seeking personality, and risky/delinquent behavior is closely connected. Investigations of environmental traits at a nonclinical level may lead us to understand the overall human personality, as with research on genes and biological traits that are implicated in the formation of mental activity.

The neurotic versus delusional subtype of taijin-kyofu-sho: their DSM diagnoses

The main purpose of the present study was to investigate the diagnostic concepts of taijin-kyofu-sho (TKS) and social phobia, by comparing the clinical diagnosis of TKS and the operational diagnosis of Diagnostic and Statistical Manual of Mental Disorders (3rd edition, revised; DSM-III-R). Three evaluators conducted semistructured interview for DSM-III-R (SCID axis I and II, the Japanese version) to 88 outpatients who visited Jikei University Daisan Hospital, Japan, over a period of 1 year, requesting Morita therapy. The patients were also independently diagnosed by three psychiatrists to identify TKS. A total of 65.8% of 38 cases of TKS were diagnosed as social phobia. Among the neurotic TKS cases, the percentage was high at 81.5%, while among the delusional TKS cases it was 27.3%. A total of 42.1% of the TKS cases were diagnosed as mood disorder; 60.5% of the TKS cases presented some axis II disorders, among which avoidant personality disorder was the most prevalent (31.6%). There was no significant difference between the neurotic and delusional subtypes of TKS, regarding comorbidity with axis I diagnoses. As for axis II diagnoses, delusional TKS patients had a higher rate of comorbidity with paranoid personality disorder, although they demonstrated very similar trends in comorbidity with all other personality disorders. In the diagnostic system of DSM-III-R, it is highly likely that the neurotic and delusional subtypes of TKS will be seen to correspond to different diagnostic categories.

Is DSM widely accepted by Japanese clinicians?

The Diagnostic and Statistical Manual of Mental Disorders, 3rd edition (DSM-III), a new standardized diagnostic system with multiaxial diagnosis, operational criteria and renewed definitions of mental disorders, was introduced in 1980 and prompted movements to reform conventions in Japanese psychiatry. This review overviews the initial response of Japanese clinicians to accept DSM-III, and its effects on the development of systematic research of psychiatric diagnosis. These new research activities include those on reliability of psychiatric diagnosis, application of various evaluation tools, discussion on the concept of mental disorders, relation of personality disorders with depressive disorders, and Taijin-kyofusho, or culturally distinctive phobia in Japan. A reference database search to survey the latest trend on psychiatric research indicated that the number of papers published by Japanese workers increased sharply after 1987, and DSM apparently greatly influenced their internationalization. Twenty years after the publication of DSM-III, a questionnaire on the use of DSM-IV was set out in 2000 to survey how widely DSM is utilized in clinical practice in Japan. Two hundred and twelve psychiatrists answered the questionnaire, and the results show that DSM has been accepted positively by the younger generation, while the older generation (over 40s) has still less interest in DSM, and DSM is used mainly for research purposes rather than in daily practice.

Serotonin transporter gene (5-HTT) polymorphisms and compulsive buying

We examined a panel of 21 patients diagnosed with compulsive buying for two DNA sequence polymorphisms found in the gene that encodes the serotonin transport (5-HTT). One polymorphism, found in the promoter region of the 5-HTT gene, involves a 44-base pair (bp) deletion, and the other, found in the second intron, is due to variable numbers of a repeat sequence. We also typed a panel of 38 psychiatrically normal controls for both 5-HH markers. When compared to this control panel, no significant differences were seen for either 5-HTT marker among the compulsive buyers.

Environmental and possible genetic contributions to character dimensions of personality

The relationship between dimensions of personality characteristics and the perceived rearing attitude of parents in the Japanese population were investigated. The scores on a measure of perceived parental attitude of 153 normal female students, measured on the Parker Parental Bonding Instrument, were correlated with personality features from the Japanese version of the Cloninger Temperament and Character Inventory. Self-directedness, especially the subclasses of Responsibility vs Blaming and Congruent Second Nature vs Incongruent Habits, was significantly related to high scores on Maternal Care and low scores on Maternal Overprotection. The subscale of Self-acceptance vs Self-striving correlated only with low scores on Maternal Overprotection. Paternal Care was only related to the total scale scores on Self-directedness. Results suggest that some personality traits may be related to the perceived attitudes of parents, especially of the mother, during childhood.

Genetically driven variation in serotonin uptake: is there a link to affective spectrum, neurodevelopmental, and neurodegenerative disorders?

Serotonin (5-HT) is an important regulator of morphogenetic activities during early central nervous system development, including cell proliferation, migration, and differentiation. The 5-HT transporter (5-HTT) plays a pivotal role in brain 5-HT homeostasis. It is also the initial target for both antidepressant drugs and drugs of abuse, some of which are potent neurotoxins. A polymorphism in the 5'-flanking regulatory region of the 5-HTT gene that results in allelic variation of 5-HTT expression is associated with anxiety-related personality traits and may influence the risk of developing affective disorders. Progress in 5-HTT gene inactivation studies are also changing views of the relevance of adaptive 5-HT uptake function in brain development and plasticity as well as processes underlying drug dependence and neurodegeneration. Despite evidence for a potential role of the 5-HTT in the integration of synaptic connections in the mammalian brain during development, adult life, and old age, detailed knowledge of the molecular mechanisms involved in these fine-tuning processes is just beginning to emerge. Integration of various strategies, including molecular genetic, transgenic, and gene transfer techniques, will allow elucidation of the 5-HTT's role in brain development, plasticity, and degeneration as well as in affective illness, drug abuse, and dementia.

Personality disorders in patients with obsessive-compulsive disorder in Japan

A total of 75 patients with obsessive-compulsive disorder (OCD) were studied in order to investigate the characteristics of OCD symptoms and the comorbidity of personality disorders (PD). Contamination obsessions and checking compulsions were most commonly found in patients, of whom 53% met the criteria for at least one PD. Among comorbid PD, the anxious-fearful (cluster C) PDs, such as avoidant, obsessive-compulsive and dependent PD, were most prevalent, followed by the odd-eccentric (cluster A) PDs, such as paranoid and schizotypal PD. The patients with PD had more severe social maladaptation and concurrent depressive and anxious symptoms than the patients without any PD, despite the similar severity of OCD symptoms. These results are consistent with those reported in the Western world, and are considered to be relatively stable cross-culturally.