OBJECTIVES: Delusions are prevalent even among members of the general population, and persecutory delusions (PDs) and grandiose delusions (GDs) are most frequently found. In this study, we investigated the differences in the dimensions of delusional ideation, reported psychosis proneness, and subjective psychotic symptoms in nonclinical individuals stratified according to the existence of PDs and GDs. METHODS: A total of 311 nonclinical individuals completed the Peters et al Delusions Inventory 40 (PDI-40), Perceptual Aberration Scale (PAS), Magical Ideation Scale (MIS), Schizotypal Personality Scale (STA), and Symptom Check List-90-R (SCL-90-R). Individuals were grouped according to four types based on the existence of PDs and GDs in PDI-40 items. RESULTS: An analysis of variance revealed that the four groups differed significantly in total delusion score, distress, preoccupation, and conviction level of delusional ideation, PAS, MAS, STA, in total SCL-90-R scores, and all SCL-90-R sub symptoms. In post-hoc analysis, the group with both PDs and GDs showed the highest scores in all measures, compared with the other three groups. CONCLUSION: We found that individuals with both PDs and GDs have a tendency to possess another delusional ideation and reported more distress, preoccupation, and conviction level of delusional ideation, psychosis proneness, and subjective symptoms. Existence of both PDs and GDs significantly elevated psychosis proneness in comparison to having only either one of them.
Delusions ; Magic ; Psychotic Disorders

OBJECTIVES: Problem behaviors pose a great obstacle to daily functioning in children with neurodevelopmental deficits and are an important target for treatment. In this study, we translated the Behavior Problems Inventory (BPI)-01 into Korean language and tested its psychometric properties. METHODS: We attained the approval of the BPI author and performed standard translation-back translation. Then, professional caregivers examined appropriateness according to cultural and situational contexts in order to make necessary modifications of the Korean version of the BPI. RESULTS: The BPI-01, Korea-Scales of Independent Behavior-Revised (K-SIB-R), and Child Behavior Checklist were completed for 98 autistic spectrum disorder or intellectual development disorder participants (mean age=28.3, standard deviation=7.3, range=10.1–51.7). The inter-rater reliability of the BPI-01 was found to be high (r=0.992–1.000). As for the results for concurrent validity for subscale items of BPI-01 and scales of SIB, correlations between SIB and BPI-01 subscales were statistically significant (r=0.357–0.672). CONCLUSION: The Korean version of the BPI-01 showed good psychometric properties with high reliability and sufficient convergent validity. Further examination of the validity of BPI-01 should be carried out with inclusion of younger aged children and a closer look at less frequently occurring symptoms.
Autism Spectrum Disorder ; Autistic Disorder ; Caregivers ; Checklist ; Child ; Child Behavior ; Humans ; Intellectual Disability ; Problem Behavior ; Psychometrics ; Reproducibility of Results ; Weights and Measures

OBJECTIVES: The purpose of this study was to examine the reliability and validity of the Korean version of the Behavior Problems Inventory (BPI-01) among children and adolescents aged between 3 and 18. METHODS: The control group consisting of one hundred children and adolescents was recruited from schools and the patient group consisting of forty one children and adolescents with autism spectrum disorder were recruited from a hospital. We compared the measurements of both groups. To assess the concurrent validity of the BPI-01, we compared the problem behavior index of the Korean Scale of Independent Behavior-Revised (K-SIB-R) and, to assess the discriminant validity, we compared the Korean version of the Child Behavior Checklist (K-CBCL). The Cronbach's alpha of the BPI-01 was measured to assess its reliability. Correlation analyses between the BPI-01 and the other scale were carried out to examine the former's concurrent and discriminant validity. RESULTS: The patient group showed a significantly higher score for all three subscales of the BPI than the control group. The Cronbach's alpha was 0.92 for the total severity score of the BPI and ranged between 0.67–0.89 for each subscale in the patient group. All subscales of the BPI-01's, i.e., self injurious behavior, stereotyped behavior and aggressive/destructive behavior, were significantly correlated with the corresponding subscales of the K-SIB-R. The BPI-01 generally did not demonstrate any significant correlation with emotional items such as anxiety/depression in the K-CBCL. Especially, the BPI-01's stereotyped behavior subscale showed little correlation with externalizing behaviors such as social problems and aggressive behaviors. CONCLUSION: This study found that the Korean version of BPI-01 is a reliable and valid behavior rating instrument for problem behavior in developmental disabilities among children and adolescents.
Adolescent* ; Autism Spectrum Disorder ; Checklist ; Child Behavior ; Child* ; Developmental Disabilities ; Humans ; Problem Behavior ; Reproducibility of Results ; Self-Injurious Behavior ; Social Problems ; Stereotyped Behavior

OBJECTIVE: The Section III of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) proposed nine diagnostic criteria and five cut-point criteria for Internet Gaming Disorder (IGD). We aimed to examine the efficacy of such criteria. METHODS: Adults (n=3041, men: 1824, women: 1217) who engaged in internet gaming within last 6 months completed a self-report online survey using the suggested wordings of the criteria in DSM-5. Major characteristics, gaming behavior, and psychiatric symptoms of IGD were analyzed using ANOVA, chi-square, and correlation analyses. RESULTS: The sociodemographic variables were not statistically significant between the healthy controls and the risk group. Among the participants, 419 (13.8%) were identified and labeled as the IGD risk group. The IGD risk group scored significantly higher on all motivation subscales (p<0.001). The IGD risk group showed significantly higher scores than healthy controls in all nine psychiatric symptom dimensions, i.e., somatization, obsession-compulsion, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism (p<0.001). CONCLUSION: The IGD risk group showed differential psychopathological manifestations according to DSM-5 IGD diagnostic criteria. Further studies are needed to evaluate the reliability and validity of the specific criteria, especially for developing screening instruments.
Adult* ; Anxiety ; Depression ; Diagnostic and Statistical Manual of Mental Disorders ; Female ; Hostility ; Humans ; Immunoglobulin D ; Internet* ; Male ; Mass Screening ; Motivation ; Reproducibility of Results