Bullying in schools has been associated with suicidal ideation but the confounding effect of psychiatric morbidity has not always been taken into account. Our main aim was to test the association between bullying behavior and early stages of suicidal ideation in a sample of Greek adolescents and to examine whether this is independent of the presence of psychiatric morbidity, including sub-threshold symptoms. 5614 pupils 16-18 years old and attending 25 senior high schools were screened in the first phase and a stratified random sample of 2431 were selected for a detailed interview at the second phase. Psychiatric morbidity and suicidal ideation were assessed with the revised Clinical Interview Schedule (CIS-R) while bullying was assessed with the revised Olweus bully/victim questionnaire. Victims of bullying behavior were more likely to express suicidal ideation. This association was particularly strong for those who were bullied on a weekly basis and it was independent of the presence of psychiatric morbidity (Odds Ratio: 7.78; 95% Confidence Interval: 3.05 - 19.90). In contrast, being a perpetrator ("bullying others") was not associated with this type of ideation after adjustment. These findings were similar in both boys and girls, although the population impact of victimization in the prevalence of suicidal ideation was potentially higher for boys. The strong cross-sectional association between frequent victimization and suicidal ideation in late adolescence offers an opportunity for identifying pupils in the school setting that are in a higher risk for exhibiting suicidal ideation.

Bullying is quite prevalent in the school setting and has been associated with the socioeconomic position and psychiatric morbidity of the pupils. The aim of the study was to investigate the association between bullying and socioeconomic status in a sample of Greek adolescents and to examine whether this is confounded by the presence of psychiatric morbidity, including sub-threshold forms of illness.

Depression is a common mental health problem in adolescents worldwide. The aim of the present study was to investigate the prevalence, comorbidity and sociodemographic and socioeconomic associations of depression and depressive symptoms, as well as the relevant health services use in a sample of adolescents in Greece. Five thousand six hundred fourteen adolescents aged 16–18 years old and attending 25 senior high schools were screened and a stratified random sample of 2,427 were selected for a detailed interview. Psychiatric morbidity was assessed with a fully structured psychiatric interview, the revised Clinical Interview Schedule (CIS-R). The use of substances, such as alcohol, nicotine and cannabis, and several sociodemographic and socioeconomic variables have been also assessed. In our sample the prevalence rates were 5.67 % for the depressive episode according to ICD-10 and 17.43 % for a broader definition of depressive symptoms. 49.38 % of the adolescents with depressive episode had at least one comorbid anxiety disorder [OR: 7.76 (5.52-10.92)]. Only 17.08 % of the adolescents with depression have visited a doctor due to a psychological problem during the previous year. Anxiety disorders, substance use, female gender, older age, having one sibling, and divorce or separation of the parents were all associated with depression. In addition, the presence of financial difficulties in the family was significantly associated with an increased prevalence of both depression and depressive symptoms. Prevalence and comorbidity rates of depression among Greek adolescents are substantial. Only a small minority of depressed adolescents seek professional help. Significant associations with financial difficulties are reported.

The global spread of COVID-19 led the World Health Organization to declare a pandemic on 11 March 2020. To decelerate this spread, countries have taken strict measures that have affected the lifestyles and economies. Various studies have focused on the identification of COVID-19’s impact on the mental health of children and adolescents via traditional statistical approaches. However, a machine learning methodology must be developed to explain the main factors that contribute to the changes in the mood state of children and adolescents during the first lockdown. Therefore, in this study an explainable machine learning pipeline is presented focusing on children and adolescents in Greece, where a strict lockdown was imposed. The target group consists of children and adolescents, recruited from children and adolescent mental health services, who present mental health problems diagnosed before the pandemic. The proposed methodology imposes: (i) data collection via questionnaires; (ii) a clustering process to identify the groups of subjects with amelioration, deterioration and stability to their mood state; (iii) a feature selection process to identify the most informative features that contribute to mood state prediction; (iv) a decision-making process based on an experimental evaluation among classifiers; (v) calibration of the best-performing model; and (vi) a post hoc interpretation of the features’ impact on the best-performing model. The results showed that a blend of heterogeneous features from almost all feature categories is necessary to increase our understanding regarding the effect of the COVID-19 pandemic on the mood state of children and adolescents.

Socioeconomic health inequalities in adolescence are not consistently reported. This may be due to the measurement of self-reported general health, which probably fails to fully capture the psychological dimension of health, and the reliance on traditional socio-economic indicators, such as parental education or occupational status. The present study aimed at investigating this issue using simple questions to assess both the physical and psychological dimension of health and a broader set of socioeconomic indicators than previously used.