Title: Exposure to violence, adverse life events and the mental health of adolescent girls in
Nairobi slums
Version: 4 Date: 07 Jan 2022
Reviewer:  Avni Amin
Reviewer's report:
This is an important analysis emerging from the clinical trial focusing on adolescent girls in
urban slum settings.  The links between exposure to violence, ACE, neighborhood context and
mental health are important to document, particularly in LMIC context as much of this work
has been documented in HICs.  That being said, I would suggest the authors in their discussion
in particular:
1. Elaborate on what the literature on exposure to violence, ACE and neighborhood context
and mental health outcomes among adolescents and children in HIC says.  The links between
violence and mental health and ACE and mental health are well established in the global
literature, albeit there is a dominance of HIC studies.  There may be useful learnings even from
HICs that may be applicable to LMIC contexts.  Therefore, it may be well worth citing and
drawing from the HIC literature.
2. Conceptually, exposure to violence, ACE and perceptions of neighborhood safety are
overlapping domains and in many settings ACE includes exposure to violence as well as to high
levels of crime in the neighborhood which form part of ACE scores.  I would suggest that the
authors in the introduction and discussion draw  on the literature on measurement of ACE -
adverse childhood events and what domains are included in ACE and articulate how exposure
to violence in adolescence and childhood and neighborhood levels of crime and safety overlap
with other measures included in the ACE that are more at the household level.  I suspect that at
least exposure to violence and items in the ACE will be highly correlated.
3. While the  measurement of physical and sexual violence uses standardized questions from
conflict tactic scales, what would be helpful is to add a measure of whether any of the physical
and sexual violence acts were perpetrated within the house or family and therefore constituted
domestic violence.   Even if it is to acknowledge whether or not majority of the violence was
perpetrated within the home or family setting and acknowledge that this is therefore highly
correlated to other measures of ACE.
4. The conclusions about the need address gender-based violence and mental health could be
strengthened by drawing on the global literature that is out there including UN prevention
frameworks like RESPECT women preventing violence against women and girls , INSPIRE
prevention of violence against children and the WHO youth violence guidelines as well as WHO
violence against women and sexual abuse against children and adolescents guidelines to be more
specific in acknowledging that there are evidence-based solutions that are out there to prevent
violence and respond to the mental health of adolescents and girls in particular.  This will help
the reader or policy maker to know what to do with the findings of this study from a policy and
action perspective and make the research to action implications much stronger.
5. Given that this is a nested study within a larger RCT focusing on adolescent girls, it is unclear
in the methodology whether the study sample drawing on the endline is that of the control arm
or the intervention arm or both and whether there are differences in the two arms.  While the
authors do make reference to the trial methods published elsewhere and indeed rightly focus on
the methodology relevant for this analysis, it would be helpful to just in brief describe what is
the intervention and whether exposure to the intervention itself was a factor in mediating the
relationship between exposure to violence, ACe, neighborhood characteristics and depression.
This is very much in the passing alluded to in the limitations, but having this spelled out in the
methodology and the analysis either as a factor or a non-factor would be helpful as it leaves
the reader wondering.
6.  In terms of the outcome measure of any depression - i.e. scores of 5 and above - I am
wondering if the authors looked at differences by severity or perhaps focused on those with
moderate, moderately severe and severe depression?  I suspect that the relationship between
exposure to violence, ACE and neighborhood characteristics and at least moderate depression
may be different.