A/HRC/43/39 are more likely to perform poorly in school, to commit crimes and to experience emotional problems, sexual problems and alcohol or substance abuse.59 74. Cognitive psychology and neuroscience studies have transformed our understanding of the potential reasons for the onset of mental disorders in adolescence. One of the unique transitions that occurs during adolescence is that the opinion of peers begins to take precedence over that of family members and parents. That sensitivity to peer influence leads to adolescents being sensitive to social stimuli and having an increased propensity for risky behaviour. Delayed maturation of the prefrontal cortex, involved in impulse control and the reward system, could be responsible for behaviour related to impulsivity and risktaking.60 75. As children begin to become more independent and interact with peer groups, they become more susceptible to interpersonal violence. Generally, children aged 10 to 18 become vulnerable to all forms of violence but the most prevalent form of violence is physical violence for both boys and girls by a member of their peer group. Along with physical attacks, that age group sees an increase in fighting between children and sometimes with violent means such as a firearm.61 76. The effects on adolescents of exposure to violence can include depression and suicidal ideation, dating violence, substance abuse and use of violence as a control tactic. 77. Adolescence involves the active search for identity and a lack of guidance at this stage could lead to poor choices. 62 The sexual coming of age and onset of sexual experiences may be adversely influenced by the results of exposure to violence and the perpetuation of violent norms of behaviour. It may be difficult for adolescents to get the appropriate style or level of help they need because the effects of exposure to violence may be masked by their own law-breaking or violent behaviour. 78. Considerable research has been done on adolescent youth violence. Such research indicates that adolescents exposed to violence, particularly those exposed to chronic community violence throughout their lives, tend to show high levels of aggression and acting out, accompanied by anxiety, behavioural problems, school problems, truancy and revenge-seeking. 79. The more severe effects on adolescents of exposure to violence may be related to the fact that they are exposed to much more violence than younger children. Such chronically traumatized youths often appear deadened to feelings and pain and show restricted emotional development over time. Alternatively, such youths may attach themselves to peer groups and gangs as a substitute for family and incorporate violence as a method of dealing with disputes or frustration.63 80. In low- and middle-income countries, recent studies have demonstrated that maternal maltreatment and exposure to violence are predictive of an increase in violent attitudes and tendencies towards children. 64 Maternal depression has also been linked to childhood disturbances in emotional, behavioural and cognitive development, including 59 60 61 62 63 64 14 See Dante Cicchetti and Sheree L. Toth, Developmental Perspectives on Trauma: Theory, Research, and Intervention (Rochester, New York, University of Rochester Press, 1998). See Vikram Patel and others, “The Lancet Commission on global mental health and sustainable development”, The Lancet, vol. 392 (October 2018). See UNICEF, Hidden in Plain Sight: a statistical analysis of violence against children (New York, UNICEF, 2014). See Esther J. Jenkins and Carl C. Bell, “Exposure and response to community violence among children and adolescents”, in Children in a Violent Society, Joy D. Osofsky, ed. (New York, Guilford Press, 1998). See Joy D. Osofsky, “Children who witness domestic violence: the invisible victims”, Social Policy Report, vol. 9, No. 3 (December 1995). Michael L. Goodman and others, “Childhood exposure to emotional abuse and later life stress among Kenyan women: a mediation analysis of cross‐sectional data”, Anxiety, Stress and Coping, vol. 30, No. 4 (2017).