Literature Review: The literature suggests that many adolescents with sexual offence histories (AWSOHs) have experienced adversity in their childhood which significantly impacted their psychosocial development. This review sought to systematically appraise the literature of 3 major data bases to explore to what extent maladaptive psychosocial development mediates the relationship between adverse childhood experiences and sexual offending in adolescents. Studies that met criteria were assessed for quality, summarised and critically evaluated; 10 papers were included for the final review. Three key findings were that emotion dysregulation (anxiety and depression), attachment (insecure) and development of offence themed fantasies mediate the relationship between childhood adversity and sexual offending in adolescence. Some papers were able to demonstrate whether and to what extent these variables mediate the relationship. Due to the methodological weaknesses of some studies, however, it is unclear how and to what extent the factors discussed in their papers mediate the relationship. The authors of the studies make suggestions for how the link could be mediated; these are evaluated in this review. The findings are discussed in the context of attachment theory and the stages of psychosocial development. The review is consistent with previous literature proposing etiological causes for sexual offending and pathways to offending. Implications for clinical practice include considerations for risk assessment, preventative measures in school and health environments and treatment options for adolescents. Future directions could include completing a qualitative review to add to this quantitative review and improving on previous methodology to make firmer conclusions. Empirical Paper: The evidence base suggests many persons with sexual offence histories (PWSOHs) have experienced adversity in their childhood. This study sought to explore the narratives of these individuals and how they believe adversity impacted on their offending behaviour. 12 men in the community who had childhood adversity, a sexual offence history and treatment within the prison and probation service volunteered to share their story. Key narratives elicited included: experiences of relationships, the absence of gendered socialisation, the internal struggle, the problem with current treatment and wider attitudes and moral issues. This analysis provides support for the developmental psychopathological perspective that suggests adversity and trauma directly impacts psychosocial and psychosexual development, creating a catalyst for later offending behaviour. Clinical implications include a need for change in societal attitudes to improve access to preventative support for at risk individuals, improved 1:1 therapy access for PWSOHs and a need for a trauma informed approach in prisons and probation. Strengths, limitations and future directions are considered. Future directions include conducting similar interviews in a prison population to explore contrasts and comparisons to the narratives from this study.