Psychotic symptoms in adolescence are associated with social adversity and genetic risk for schizophrenia. This gene–environment interplay may be mediated by personality, which also develops during adolescence. We hypothesized that (i) personality development predicts later Psychosis Proneness Signs (PPS), and (ii) personality traits mediate the association between genetic risk for schizophrenia, social adversities, and psychosis.

A total of 784 individuals were selected within the IMAGEN cohort (Discovery Sample-DS: 526; Validation Sample-VS: 258); personality was assessed at baseline (13–15 years), follow-up-1 (FU1, 16–17 years), and FU2 (18–20 years). Latent growth curve models served to compute coefficients of individual change across 14 personality variables. A support vector machine algorithm employed these coefficients to predict PPS at FU3 (21–24 years). We computed mediation analyses, including personality-based predictions and self-reported bullying victimization as serial mediators along the pathway between polygenic risk score (PRS) for schizophrenia and FU3 PPS. We replicated the main findings also on 1132 adolescents recruited within the TRAILS cohort.

Growth scores in neuroticism and openness predicted PPS with 65.6% balanced accuracy in the DS, and 69.5% in the VS Mediations revealed a significant positive direct effect of PRS on PPS (confidence interval [CI] 0.01–0.15), and an indirect effect, serially mediated by personality-based predictions and victimization (CI 0.006–0.01), replicated in the TRAILS cohort (CI 0.0004–0.004).

Adolescent personality changes may predate future experiences associated with psychosis susceptibility. PPS personality-based predictions mediate the relationship between PRS and victimization toward adult PPS, suggesting that gene–environment correlations proposed for psychosis are partly mediated by personality.

Caused by multiple risk factors, heavy burden of major depressive disorder (MDD) poses serious challenges to public health worldwide over the past 30 years. Yet the burden and attributable risk factors of MDD were not systematically known. We aimed to reveal the long-term spatio-temporal trends in the burden and attributable risk factors of MDD at global, regional and national levels during 1990–2019.

We obtained MDD and attributable risk factors data from Global Burden of Disease Study 2019. We used joinpoint regression model to assess the temporal trend in MDD burden, and age–period–cohort model to measure the effects of age, period and birth cohort on MDD incidence rate. We utilized population attributable fractions (PAFs) to estimate the specific proportions of MDD burden attributed to given risk factors.

During 1990–2019, the global number of MDD incident cases, prevalent cases and disability-adjusted life years (DALYs) increased by 59.10%, 59.57% and 58.57%, respectively. Whereas the global age-standardized incidence rate (ASIR), age-standardized prevalence rate (ASPR) and age-standardized DALYs rate (ASDR) of MDD decreased during 1990–2019. The ASIR, ASPR and ASDR in women were 1.62, 1.62 and 1.60 times as that in men in 2019, respectively. The highest age-specific incidence, prevalence and DALYs rate occurred at the age of 60–64 in women, and at the age of 75–84 in men, but the maximum increasing trends in these age-specific rates occurred at the age of 5–9. Population living during 2000–2004 had higher risk of MDD. MDD burden varied by socio-demographic index (SDI), regions and nations. In 2019, low-SDI region, Central sub-Saharan Africa and Uganda had the highest ASIR, ASPR and ASDR. The global PAFs of intimate partner violence (IPV), childhood sexual abuse (CSA) and bullying victimization (BV) were 8.43%, 5.46% and 4.86% in 2019, respectively.

Over the past 30 years, the global ASIR, ASPR and ASDR of MDD had decreased trends, while the burden of MDD was still serious, and multiple disparities in MDD burden remarkably existed. Women, elderly and populations living during 2000–2004 and in low-SDI regions, had more severe burden of MDD. Children were more susceptible to MDD. Up to 18.75% of global MDD burden would be eliminated through early preventing against IPV, CSA and BV. Tailored strategies-and-measures in different regions and demographic groups based on findings in this studywould be urgently needed to eliminate the impacts of modifiable risk factors on MDD, and then mitigate the burden of MDD.

Adolescent suicide is a severe public health problem in low- and middle-income countries (LMICs), and adolescents who are victims of bullying have a higher risk of suicidal behaviours. However, detailed global data concerning the association between bullying victimisation and suicide are lacking; thus, further multicontinental studies exploring the association of bullying victimisation at different frequencies and types with suicidal behaviours are urgent.

The data were extracted from the Global School-based Student Health Survey (GSHS) (2010–2017) conducted in 40 LMICs (n = 151 184, mean age: 14.77 years, s.d.: 1.59, 54.2% females). Data concerning past-30-day bullying victimisation, past 12-month suicidal behaviours (suicidal ideation, suicidal plans and suicidal attempts) and other adverse health behaviours or outcomes were collected. Chi-square tests were used to explore the correlations among the main variables. A multivariable logistic regression and stratified logistic regressions were conducted to assess the associations.

The overall prevalence of bullying victimisation, suicidal ideation, suicidal plans and suicidal attempts were 28.72, 12.64, 11.84 and 10.79%, respectively. The results showed a positive association of different frequencies and types of bullying victimisation with suicidal behaviours: suicidal ideation (odds ratio (OR) = 2.43, 2.06–2.87), suicidal plans (OR = 2.69, 2.28–3.17) and suicidal attempts (OR = 3.23, 2.73–3.82). Adolescents also reported the effects of being made fun of because of their religion: suicidal ideation (OR = 1.63, 1.41–1.88), suicidal plans (OR = 1.44, 1.24–1.66) and suicidal attempts (OR = 1.73, 1.50–1.98). Moreover, these associations varied among teenagers of different gender and body mass indexes (BMIs) and were stronger among males and adolescents who were underweight, overweight or obese.

Different types of bullying victimisation were positively related to suicidal behaviours; these associations varied among adolescents by gender and BMI. This study offers a theoretical basis for the identification of adolescents at a high risk of suicide and is beneficial for informing effective psychological interventions for constructing sound school environments, improving adolescents’ mental health and reducing the risk of suicide to promote health in LMICs and globally.

Experience of bullying may be a significant risk factor for non-suicidal self-injury (NSSI).

This study had three aims: to systematically investigate the association between bullying and NSSI, to analyze the possible mechanisms underlying the two phenomena, and to evaluate any differences between bullying victimization and bullying perpetration with respect to NSSI.

A systematic search about the association between bullying victimization and perpetration and NSSI was conducted using specific databases (PubMed, Scopus, Science Direct). The following keywords were used in all database searches: “bullying” AND “NSSI” OR “peer victimization” and NSSI.

The searches in PubMed, Scopus and Science Direct revealed a total of 88 articles about bullying or peer victimization and NSSI. However, only 29 met our inclusion criteria and were used for the present review. Overall, all studies examined victimization; 4 studies also evaluated the effects of perpetration and 1 included bully-victims. According to the main findings, both being a victim of bullying and perpetrating bullying may increase the risk of adverse psychological outcomes in terms of NSSI and suicidality in the short and the long run.

To the best of our knowledge, this is the first review to systematically evaluate the relation between bullying victimization/perpetration and NSSI. The main results support a positive association. Future research should evaluate the possible role of specific mediators/moderators of the association between experience of bullying and NSSI.

No significant relationships.

Bullying victimization in childhood is associated with a broad array of serious mental health disturbances, including anxiety, depression, and suicidal ideation and behavior. The key goal of this study was to evaluate whether bullying victimization is a true environmental risk factor for psychiatric disturbance using data from 145 bully-discordant monozygotic (MZ) juvenile twin pairs from the Virginia Twin Study of Adolescent Behavioral Development (VTSABD) and their follow-up into young adulthood.

Since MZ twins share an identical genotype and familial environment, a higher rate of psychiatric disturbance in a bullied MZ twin compared to their non-bullied MZ co-twin would be evidence of an environmental impact of bullying victimization. Environmental correlations between being bullied and the different psychiatric traits were estimated by fitting structural equation models to the full sample of MZ and DZ twins (N = 2824). Environmental associations were further explored using the longitudinal data on the bullying-discordant MZ twins.

Being bullied was associated with a wide range of psychiatric disorders in both children and young adults. The analysis of data on the MZ-discordant twins supports a genuine environmental impact of bullying victimization on childhood social anxiety [odds ratio (OR) 1.7], separation anxiety (OR 1.9), and young adult suicidal ideation (OR 1.3). There was a shared genetic influence on social anxiety and bullying victimization, consistent with social anxiety being both an antecedent and consequence of being bullied.

Bullying victimization in childhood is a significant environmental trauma and should be included in any mental health assessment of children and young adults.

There has been considerable recent interest in possible causal linkages between exposure to bullying victimization and later psychotic symptomatology. Prior research in this area has had several limitations which make it difficult to ascertain causality, and to determine the extent to which these effects extend beyond adolescence.

Data were obtained from the Christchurch Health and Development Study, a 35-year study of a longitudinal birth cohort. This investigation used generalized estimating equation modelling to estimate the associations between bullying victimization (ages 13–16 years) and psychotic symptoms (ages 18–35 years), before and after controlling for possible confounding factors, including: gender; childhood socio-economic status; child intelligence quotient; exposure to sexual abuse in childhood; anxious/withdrawn behaviour and attention problems (ages 7–9 years); and adolescent psychotic symptoms and paranoid ideation (ages 15–16 years).

There was a significant (p < 0.0001) bivariate association between bullying victimization in adolescence and psychotic symptomatology in adulthood. Successive models controlling for covariation reduced this association to statistical non-significance. After controlling for covariates, those with the highest level of bullying victimization had rates of psychotic symptoms that were 1.21 (95% confidence interval 0.73–1.99) times higher than those who were not victimized.

The association between bullying victimization in adolescence and psychotic symptomatology in adulthood could be largely explained by childhood behavioural problems, and exposure to sexual abuse in childhood. The results suggest that bullying victimization was unlikely to have been a cause of adult psychotic symptoms, but bullying victimization remained a risk marker for these symptoms.

We aimed to test whether childhood bullying victimization increases risk for age-related disease at mid-life using biological markers including inflammation and adiposity, independent of other childhood risk factors and key adult variables.

The present study was a 50-year prospective longitudinal birth cohort study of all births in Britain in 1 week in 1958. Exposure to bullying was assessed prospectively when participants were aged 7 and 11 years (27.7% occasionally bullied; 14.6% frequently bullied). Blood inflammation biomarkers [C-reactive protein (CRP) and fibrinogen] and adiposity [body mass index (BMI) and waist:hip ratio] were measured at age 45 years.

Participants who had been frequently bullied in childhood showed increased levels of CRP at mid-life [β = 0.07, 95% confidence interval (CI) 0.04–0.10] and higher risk for clinically relevant inflammation cut-off [CRP > 3 mg/l: 20.4% v. 15.9%, odds ratio (OR) = 1.35, 95% CI 1.12–1.64]. Women who were bullied in childhood had higher BMI than non-bullied participants and were at increased risk of being obese (BMI ≥ 30 kg/m2: occasionally bullied: 26.0% v. 19.4%, OR = 1.45, 95% CI 1.18–1.77; frequently bullied: 26.2% v. 19.4%, OR = 1.41, 95% CI 1.09–1.83). Findings remained significant when controlling for childhood risk factors (e.g. parental social class; participants’ BMI and psychopathology in childhood) and key adult variables (e.g. adult social class, smoking, diet and exercise).

Bullied children show increases in risk factors for age-related disease in middle adulthood, independent of co-occurring childhood and adult risks. Given the high prevalence of bullying victimization in childhood, tackling this form of psychosocial stress early in life has the potential of reducing risk for age-related disease and its associated burden.

Bullying victimization may be linked to psychosis but only self-report measures of victimization have been used so far. This study aimed (a) to investigate the differential associations of peer-nominated versus self-reported victim status with non-clinical psychotic experiences in a sample of young adolescents, and (b) to examine whether different types of self-reported victimization predict non-clinical psychotic experiences in these adolescents.

A combination of standard self-report and peer nomination procedures was used to assess victimization. The sample (n = 724) was divided into four groups (exclusively self-reported victims, self- and peer-reported victims, exclusively peer-reported victims, and non-victims) to test for a group effect on non-clinical psychotic experiences. The relationship between types of victimization and non-clinical psychotic experiences was examined by a regression analysis.

Self-reported victims, along with self- and peer-reported victims, scored higher than peer-reported victims and non-victims on non-clinical psychotic experiences. Self-reports of direct relational, indirect relational and physical victimization significantly improved the prediction of non-clinical psychotic experiences whereas verbal and possession-directed victimization had no significant predictive value.

The relationship between victimization and non-clinical psychotic experiences is only present for self-reported victimization, possibly indicative of an interpretation bias. The observed discrepancy between self-report and peer-report highlights the importance of implementing a combination of both measures for future research.

Approximately 11% of schoolchildren are bullied on a regular basis. It has been argued that continuous exposure to stress is related to the development of psychotic symptoms. The current study sought to investigate whether being bullied in childhood is related to the development of psychotic symptoms.

A search of PubMed, PsycINFO and EMBASE was conducted. The reference lists of included papers were searched to identify other eligible papers. A meta-analysis was performed on a subgroup of studies.

We found four clinical and 10 general population studies that met inclusion criteria. The results of the clinical studies were mixed. However, the results of the non-clinical studies provided more consistent evidence that school bullying is related to the development of non-clinical psychotic symptoms. Stronger associations were found with increased frequency and severity and longer duration of being bullied. We performed a meta-analysis on seven population-based studies, yielding unadjusted and adjusted odds ratios (ORs) of 2.7 [95% confidence interval (CI) 2.1–3.6] and 2.3 (95% CI 1.5–3.4) respectively.

Although there is some evidence of an association between bullying and psychosis in clinical samples, the research is too sparse to draw any firm conclusions. However, population-based non-clinical studies support the role of bullying in the development of psychotic symptoms later in life. These findings are consistent with findings of an increased risk of psychotic symptoms among those exposed to other types of abuse.