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Tourette syndrome (TS) is a neuropsychiatric disorder with involvement of genetic and environmental factors. We investigated genetic loci previously implicated in Tourette syndrome and associated disorders in interaction with pre- and perinatal adversity in relation to tic severity using a case-only (N = 518) design. We assessed 98 single-nucleotide polymorphisms (SNPs) selected from (I) top SNPs from genome-wide association studies (GWASs) of TS; (II) top SNPs from GWASs of obsessive–compulsive disorder (OCD), attention-deficit/hyperactivity disorder (ADHD), and autism spectrum disorder (ASD); (III) SNPs previously implicated in candidate-gene studies of TS; (IV) SNPs previously implicated in OCD or ASD; and (V) tagging SNPs in neurotransmitter-related candidate genes. Linear regression models were used to examine the main effects of the SNPs on tic severity, and the interaction effect of these SNPs with a cumulative pre- and perinatal adversity score. Replication was sought for SNPs that met the threshold of significance (after correcting for multiple testing) in a replication sample (N = 678). One SNP (rs7123010), previously implicated in a TS meta-analysis, was significantly related to higher tic severity. We found a gene–environment interaction for rs6539267, another top TS GWAS SNP. These findings were not independently replicated. Our study highlights the future potential of TS GWAS top hits in gene–environment studies. [ABSTRACT FROM AUTHOR]

A teacher as a suicide prevention gatekeeper has an important role in identifying suicide risks and warning signs in students. After a student's suicide, teachers in Korea have to write a student suicide case report based on their direct and indirect observations. In particular, the section 'characteristic of student suicide' of this report contains valuable information about the suicide; however, it is unstructured, and thus cannot be analyzed using conventional statistical methods. We aimed to identify the characteristics of observed Korean students, who have committed suicide, using text mining techniques as well as to improve our understanding of suicidal behaviors in the school contexts. Therefore, a series of text mining techniques: topic analysis, word correlation, and word frequency analysis, in three problem categories: health, school, and family problems, were used to analyze the characteristics of student suicides. Topic analysis showed that only 30% of the student suicide case reports identified problematic student characteristics related to suicide. Correlations between words showed that words in one problem category were often correlated with words in other problem categories. Frequency word analysis showed that the three problem categories varied across gender and school levels. These results provide interesting insights into the characteristics of suicides among Korean students and important implications for suicide intervention in the education field. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the risk factors for suicidal ideation in adolescents by gender and age. This study used 2013 nationwide school-based mental health screening test data from 591,303 seventh grade students and 618,271 tenth grade students in Korea. Suicidal ideation, four psychological problems, and three adverse life events were evaluated using the Adolescents Mental Health and Problem Behavior Screening Questionnaire-II. Of all students, 12.9-14.7% of the boys and 17.1-23.2% of the girls had suicidal ideation. Mood had the greatest impact on the risk for suicidal ideation and other factors also significantly increased the risk of suicidal ideation. Distractibility was positively related to suicidal ideation only in seventh grade students and behavioral problems increased suicidal ideation more in girls than in boys. Violence constituted the most powerful factor for suicidal ideation among the events; however, bullying constituted the most important event that increased suicidal ideation in seventh grade girls. All factors except ‘Distractibility’ increased the risk of severe suicidal ideation. The risk factors for suicidal ideation in adolescents differed by gender and age. Interventions should be made according to these characteristics to reduce suicidal ideation in adolescents. [ABSTRACT FROM AUTHOR]

Genetic studies in Tourette syndrome (TS) are characterized by scattered and poorly replicated findings. We aimed to replicate findings from candidate gene and genome-wide association studies (GWAS). Our cohort included 465 probands with chronic tic disorder (93% TS) and both parents from 412 families (some probands were siblings). We assessed 75 single nucleotide polymorphisms (SNPs) in 465 parent-child trios; 117 additional SNPs in 211 trios; and 4 additional SNPs in 254 trios. We performed SNP and gene-based transmission disequilibrium tests and compared nominally significant SNP results with those from a large independent case-control cohort. After quality control 71 SNPs were available in 371 trios; 112 SNPs in 179 trios; and 3 SNPs in 192 trios. 17 were candidate SNPs implicated in TS and 2 were implicated in obsessive-compulsive disorder (OCD) or autism spectrum disorder (ASD); 142 were tagging SNPs from eight monoamine neurotransmitter-related genes (including dopamine and serotonin); 10 were top SNPs from TS GWAS; and 13 top SNPs from attention-deficit/hyperactivity disorder, OCD, or ASD GWAS. None of the SNPs or genes reached significance after adjustment for multiple testing. We observed nominal significance for the candidate SNPs rs3744161 (TBCD) and rs4565946 (TPH2) and for five tagging SNPs; none of these showed significance in the independent cohort. Also, SLC1A1 in our gene-based analysis and two TS GWAS SNPs showed nominal significance, rs11603305 (intergenic) and rs621942 (PICALM). We found no convincing support for previously implicated genetic polymorphisms. Targeted re-sequencing should fully appreciate the relevance of candidate genes. [ABSTRACT FROM AUTHOR]