4.4 Strengths and Limitations
The study’s strengths include the assessment of a complete FEP cohort using validated diagnostic and clinical instruments; the use of a standardised assessment measure ensured a reliable definition of trauma-exposure reporting. Furthermore, the sample size was appropriately powered for the statistics used. This study design is a partial replication of the study design used by Conus et al. (2010) in a similar FEP cohort in Melbourne Australia.
Limitations include that the TALE measure was originally designed as a questionnaire or interview tool. This is a novel use of the TALE to retrospectively categorise and classify the information recorded in clinical assessments. Previous studies using this methodology pre-date the development of the TALE and used other trauma-exposure frameworks. As a result, the researchers may have incorrectly attributed difficult life events as traumatic, which would account for the high prevalence of trauma-exposure. Nonetheless, the rates reported in this study are in line with other trauma exposure assessed in other FEP cohorts (Conus et al., 2010; DeTore et al., 2021; Neria et al., 2002). All assessments were performed by senior clinical staff. However, interviewing participants would allow for a more detailed assessment and classification of trauma. The retrospective use of the TALE should be validated in a further study. This study did not measure trauma severity or PTSD symptoms, which may have a stronger link to symptomology (Conus et al., 2010; DeTore et al., 2021). It is reasonable to assume that the more severe trauma exposure, the more severe their psychosis symptoms may be. In a prospective study using the TALE, recurrent trauma-exposure but not trauma-exposure alone was a significant predictor of symptoms severity (Grady et al., under review).