BACKGROUND: The increase in tobacco/conventional cigarette (CC) and electronic cigarette (EC) usage among Chinese youth has become a growing public health concern. This is the first large-scale study to compare the impact of CC and EC usage on risk for nonsuicidal self-injury (NSSI) and suicidality in cis-heterosexual and sexual and gender minority (SGM) youth populations in China.
OBJECTIVE: This study examines the CC and EC risks for NSSI and suicidality among Chinese youth and compares the extent to which SGM and cis-heterosexual youth\'s risks for NSSI and suicidality are influenced by their CC and EC usage and dependence.
METHODS: A total of 89,342 Chinese participants completed a cross-sectional self-report survey in 2021. Sociodemographic information, sexual orientations, gender identities, CC and EC usage, CC and EC dependence, and risks for suicidality and NSSI were assessed. The Mann-Whitney U test and chi-square test were performed for nonnormally distributed continuous variables and categorical variables, respectively. The multivariable linear regression model was used to examine both the influence of CC and EC usage and CC and EC dependence on NSSI and suicidality as well as the interaction effects of CC and EC usage and CC and EC dependence on NSSI and suicidality by group.
RESULTS: The prevalence of CC usage (P<.001) and dependence (P<.001) among SGM participants was lower than that among their cis-heterosexual counterparts. However, the prevalence of EC usage (P=.03) and EC dependence (P<.001) among SGM participants was higher than that among their cis-heterosexual counterparts. The multivariable linear regression model showed that CC dependence and EC dependence had a unique effect on NSSI and suicidality (CCs: B=0.02, P<.001; B=0.09, P<.001; ECs: B=0.05, P<.001; B=0.14, P<.001, respectively). The interaction effects of (1) CC usage and group type on NSSI and suicidality (B=0.34, P<.001; B=0.24, P=.03, respectively) and dual usage and group type on NSSI and suicidality (B=0.54, P<.001; B=0.84, P<.001, respectively) were significant, (2) CC dependence and group type on NSSI were significant (B=0.07, P<.001), and (3) EC dependence and group type on NSSI and suicidality were significant (B=0.04, P<.001; B=0.09, P<.001, respectively). No significant interaction effect was observed between EC usage and group type on NSSI and suicidality (B=0.15, P=.12; B=0.33, P=.32, respectively) and between CC dependence and group type on suicidality (B=-0.01, P=.72).
CONCLUSIONS: Our study shows evidence of intergroup differences in NSSI and suicidality risks between SGM and cis-heterosexual youth related to CC and EC usage. These findings contribute to the growing literature on CC and EC in cis-heterosexual and SGM populations. Concerted efforts are necessary at a societal level to curb the aggressive marketing strategies of the EC industry and media coverage and to maximize the impact of educational campaigns on EC prevention and intervention among the youth population.

The purpose of this study was to determine whether individuals who have experienced a transient ischemic attack (TIA) have an increased risk of self-harm behaviors.
In this matched cohort study, we reviewed the electronic health records of all patients admitted for any reason to Hong Kong public hospitals between January 1, 1993, and December 31, 2019. We selected a post-TIA cohort consisting of 37,356 patients and a comparison cohort comprising 37,352 subjects. All participants enrolled in this study were followed up until a diagnosis of self-harm, death from other causes, or the end of 2020, whichever occurred first. Univariate Cox proportional hazards regression models were used to calculate the risk of self-harm since the onset of TIA.
Throughout the 27-year study period, the number of individuals exhibiting self-harm behavior in the TIA and comparison groups was 1031 (2.76%) and 512 (1.37%), respectively. The TIA group had a higher proportion of subjects with self-harm (χ2 = 178, p < .001). The incidence rates of self-harm were 33.94 and 19.27 per 10,000 person-years in TIA patients and comparators, respectively. Compared with the comparators, the adjusted hazard ratio for self-harm in TIA patients was 1.63 (95% confidence interval, 1.46-1.82).
TIA is associated with an increased risk of self-harm. Healthcare professionals should help identify patients at heightened risk and provide efficient and targeted prevention strategies for this population.

Suicide is the most severe consequence of depression which has become a leading cause of disability and a global disease burden. Recent evidence indicates a central role of small molecules in the pathogenesis of depression and associated suicidal behaviors. However, there lacks a systemic exploration of small molecules in the development of depression-associated suicide, and it remains unclear how they affect an individual\'s behavior. In order to compare the metabonomic profiles between drug-naïve patients with depression-associated suicidal behaviors and healthy individuals, we conducted a systemic database search for studies of metabolic characteristics in depression-associated suicidal behavior. Manual data curation and statistical analysis and integration were performed in Excel. We further performed an enrichment analysis of signaling pathway prediction using the Reactome Pathway Analysis tool. We have identified 17 metabolites that expressed differently between drug-naïve patients with depression-associated suicidal behaviors and healthy controls. We have integrated these metabolites into biological signaling pathways and provided a visualized signaling network in depressed suicidal patients. We have revealed that \"transport of small molecules\", \"disease\", \"metabolism\" and \"metabolism of proteins\" were the most relevant signaling sections, among which \"transport of inorganic cations/anions and amino acids/oligopeptides\", \"SLC-mediated transmembrane transport\", and \"metabolism of amino acids and derivatives\" should be further studied to elucidate their potential pathogenic mechanism in the development of depression and associated suicidal behavior. In conclusion, our findings of these 17 metabolites and associated signaling pathways could provide an insight into the molecular pathogenesis of depression-associated suicidal behavior and potential targets for new drug inventions.