Footnotes

• Contributors KZ takes public responsibility for the entire work, from idea to complete manuscript. All authors meet the following criteria for authorship: substantial involvement and contribution to the idea or the study question, or to the study design, or to the fieldwork component, or to the analysis, or to the interpretation of study findings; writing drafts of the manuscript, or reviewing drafts or revisions critically with substantial input and approval of the final version of the manuscript.

• Funding This study was funded by Foundation Markets Foundation for Children.

• Competing interests None declared.

• Patient consent Obtained.

• Ethics approval Ethics approval for the community sample in these studies was granted by the Human Research Ethics Committee Northern Hospitals Network, South Eastern Sydney Illawarra Area Health Service (HREC Reference Numbers 08/084 and 09/163), including approval to compare this sample with the detention sample on 21/6/2017. The research involving the detention sample in this study was assessed by the South Western Sydney Local Health District Human Research Ethics Committee (HREC/15/LPOOL/556), which was satisfied with provisions to protect the rights of participants. All participants gave their informed consent prior to their inclusion in the study.

• Provenance and peer review Not commissioned; internally peer reviewed.