Protective factors for psychotic phenomena amongst children and adolescents exposed to multiple forms of victimisation

Student thesis: Doctoral ThesisDoctor of Philosophy


Psychotic phenomena, such as hearing voices and being extremely paranoid, represent some of the most extraordinary and distressing mental states. Children and adolescents are significantly more likely to experience psychotic phenomena when they have been exposed to multiple forms of victimisation (poly-victimisation) although a substantial proportion of poly-victimised individuals will not develop these experiences. This thesis investigates why certain high-risk individuals do not develop psychotic phenomena in order to eventually inform early intervention efforts to prevent the emergence of psychotic phenomena among poly-victimised youth. Specifically, this thesis comprises four studies which investigate individual, family and community-level factors which are protective in relation to psychotic phenomena among poly-victimised children and adolescents. Analyses use data from the Environmental-Risk (E-Risk) Longitudinal Twin Study, a birth cohort of 2,232 twin children born in 1994 and 1995 in England and Wales. The first study investigates multi-level protective factors for age-12 psychotic phenomena among children exposed to polyvictimisation. The second study explores multi-level protective factors for age-18 psychotic experiences among poly-victimised adolescents. The third study considers gender differences in terms of the protective influences of social support on psychotic phenomena among poly-victimised adolescents. The fourth study utilises discordant twin methods to investigate whether the association between social support and the absence of adolescent psychotic experiences is environmentally mediated, after accounting for family-wide (including genetic) factors. Collectively, these studies identify multi-level protective factors for psychotic phenomena amongst poly-victimised youth, although these also appear to be associated with an absence of psychotic phenomena in this cohort regardless of polyvictimisation exposure. If replicated, these findings will have practical implications for interventions aiming to prevent the occurrence of early psychotic phenomena and the potential to prevent subsequent mental health problems.
Date of Award1 Apr 2019
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorHelen Fisher (Supervisor) & Louise Arseneault (Supervisor)

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