The prevalence & correlates of first episode psychosis (FEP) and the impact of trauma and discrimination on risk of FEP

Student thesis: Doctoral ThesisDoctor of Clinical Psychology


Background. Exposure to trauma has been linked with the onset and maintenance of psychosis. As trauma is a prerequisite for Post-Traumatic Stress Disorder (PTSD), it also raises the question of potential associations between the two psychiatric disorders. The prevalence rates for PTSD symptoms in psychosis is estimated at 40% and between 20-40% for the inverse relationship. Furthermore, research data have evidenced ethnic differences in the rates of psychosis and PTSD, as well as experience of trauma, independently. However, research investigating the coexistence of this phenomenon and ethnic variations in the prevalence rates is limited. Thus, this review sought identify, critically evaluate the literature and summarise the prevalence of comorbid trauma/PTSD and psychosis, looking at whether rates of these vary by ethnicity. Method. PsycINFO, MEDLINE and Web of Science electronic databases were searched for studies reporting the comorbidity rates of trauma/PTSD and psychosis disaggregated by ethnic groups. Findings were synthesised qualitatively for eligible studies relevant to the review question. In addition, a quality assessment of included studies was conducted with the aim of determining the methodological rigour and robustness of conclusions that can be reached. Results. A total of 751 citations were screened and nine studies (sample size between studies varying from 18 to 8124 participants) were identified as meeting inclusion criteria for this review. Five studies showed evidence of ethnic variations in comorbid prevalence rates of trauma/PTSD and psychosis. However, there were variations between studies in the methodology used with some limitations identified, resulting in varying quality of the literature.
Conclusion. Although some findings supported the disaggregation of experiences studied by ethnicity, it is not possible to draw firm conclusions given the heterogeneity and limitations of methodology identified. Future research direction should aim for quantitative synthesis and addressing methodological practices.
Date of Award2018
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorCraig Morgan (Supervisor) & Lucia Valmaggia (Supervisor)

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