Violences, suicidal behaviour, and non-suicidal self-injury in child development: findings from a Brazilian cohort

Violence and mental health have a large proportion within the global burden of disease for children and youth, especially with the growing magnitude of suicidal behaviour and non-suicidal self-injury. This longitudinal study examined for the effects of physical and psychological family and community violence during childhood, adolescence and youth and the emergence of suicidal behaviour and non-suicidal self-injury among young people.

129 participants, from a cohort of 500 students (mean age 8 years, SD 1.2) sampled at schools in a Brazilian metropolis (2005), were followed up for 16 years (2006, 2008, 2012, 2021). Suicidal behaviour/non-suicidal self-injury by the youth was the dependent variable assessed at the fifth wave of the study by Adult Self Report/Achenbach System of Empirically Based Assessment (ASR/ASEBA) and Youth Risk Behavior Survey Scale (YRBSS). The independent variables were 193 questions on violence (Conflict Tactics Scale - CTS - and "Things I have seen and heard"), which were assessed longitudinally. Three groups of violence (physical family violence, psychological family violence and community violence), plus the three stages of development studied (childhood, adolescence and youth), resulted in nine violence events, which were examined descriptively and input to structural equation modelling.

The outcome was found in 37% of the participants, combining all time points. The forms of violence that occurred in childhood, adolescence and youth were, respectively: physical family violence: 84.5%, 14% and 15.5%; psychological family violence: 76.7%, 3.9% and 76.7%; and community violence: 18%, 12.4% and 40.3%. The modelling revealed a network between types of violence: community and psychological (0.348; p < 0.001) in childhood; community and psychological (0.302; p < 0.001) and physical and psychological (0.374; p = 0.001) in youth; and among all types of violence in adolescence. Regarding the outcome, the following factors were prominent: psychological family violence in childhood (0.656; p = 0.006), community violence in adolescence (0.517; p < 0.001) and psychological family violence in youth (0.398; p < 0.001).

The study highlighted the effect of different forms of violence longitudinally with suicidal behaviour and non-suicidal self-injury in youth, underlining the value of preventing violence as an important vector in related intervention.