A systematic review and meta-analysis of the traumatogenic phenotype hypothesis of psychosis.

BACKGROUND: Developmental trauma increases psychosis risk and is associated with poor prognosis. It has been proposed that psychosis in survivors of developmental trauma gives rise to a distinct 'traumatogenic' phenotype. AIMS: Given the implications for personalised treatment, we sought to explore the traumatogenic psychosis phenotype hypothesis in a systematic review and meta-analysis of studies comparing psychotic presentations between adults with and without developmental trauma histories. METHOD: We registered the systematic review on PROSPERO (CRD42019131245) and systematically searched EMBASE, Medline and PsycINFO. The outcomes of interests were quantitative and qualitative comparisons in psychotic symptom expression (positive, negative, cognitive) and other domains of psychopathology, including affect regulation, sleep, depression and anxiety, between adults with and without experience of developmental trauma. RESULTS: Of 34 studies included (N = 13 150), 11 were meta-analysed (n = 2842). A significant relationship was found between developmental trauma and increased symptom severity for positive (Hedge's g = 0.27; 95% CI 0.10-0.44; P = 0.002), but not negative symptoms (Hedge's g = 0.13; 95% CI -0.04 to 0.30; P = 0.14). Developmental trauma was associated with greater neurocognitive, specifically executive, deficits, as well as poorer affect, dissociation and social cognition. Furthermore, psychotic symptom content thematically related to traumatic memories in survivors of developmental trauma. CONCLUSIONS: Our findings that developmental trauma is associated with more severe positive and affective symptoms, and qualitative differences in symptom expression, support the notion that there may be a traumatogenic psychosis phenotype. However, underdiagnosis of post-traumatic stress disorder may also explain some of these findings. More research is needed to explore this further.

Head Trauma in Refugees and Asylum Seekers: A Systematic Review.

BACKGROUND AND OBJECTIVES: Refugees and asylum seekers are at risk of head trauma. They endure blows to the head due to exigent circumstances necessitating resettlement (e.g., torture, war, interpersonal violence) and during their dangerous journeys to refuge. Our objective was to assess the global prevalence of head trauma in refugees and asylum seekers and describe its clinical characteristics in this population. METHODS: The protocol was registered in the PROSPERO International Prospective Register of Systematic Reviews (CRD42020173534). PubMed/MEDLINE, PsycInfo, Web of Science, Embase, and Google Scholar databases were searched for relevant studies. We included all studies in English that comprised refugees or asylum seekers of any age and examined the prevalence or characteristics of head trauma. We excluded studies that were not peer-reviewed original research. Information was recorded on the prevalence of head trauma, method of ascertaining head trauma, severity, mechanism of injury, other trauma exposures, and comorbidities. Descriptive analyses and narrative syntheses were performed. RESULTS: A total of 22 studies were included, of which 13 with 6,038 refugees and asylum seekers reported head trauma prevalence. Prevalence estimates ranged from 9% to 78%. Heterogeneity among studies precluded meta-analysis. Most studies were US based (n = 9, 41%), followed by the Middle East (n = 5, 23%). Most refugees or asylum seekers were from the Middle East (n = 9, 41%), with those from Latin America least represented (n = 3, 14%). Studies disproportionately involved younger (pooled mean age = 29 years) adult samples composed of men. Recruitment settings were predominantly hospitals/clinics (n = 14, 64%), followed by refugee camps (n = 3, 14%). The most common mechanism of injury was direct impact through a beating or blow to the head. Studies varied greatly in how head trauma was defined and ascertained; no study used a validated traumatic brain injury (TBI)-specific screening tool. Similarly, TBI severity was not uniformly assessed, although hospital-based samples captured more moderate-to-severe head injuries. Mental health comorbidities were more frequently documented rather than physical health ones. Only 2 studies included a comparison with local populations. DISCUSSION: Refugees and asylum seekers are vulnerable to head trauma, but studies using systematic approaches to screening are lacking. Increased attention to head trauma in displaced populations will allow for optimizing equitable care for this growing vulnerable population.

The effects of developmental trauma on theory of mind and its relationship to psychotic experiences: A behavioural study.

BACKGROUND: Developmental psychological trauma induces vulnerability to psychosis. However, the mechanisms underlying this association are poorly understood. Impairments in Theory of Mind (ToM) have been observed in adult survivors of developmental trauma and individuals with psychosis. ToM is therefore a candidate mechanism underlying the association between developmental trauma and psychosis. METHODS: We used a computerised version of the Director task - where a participant is instructed by a confederate to move an object around a 4 × 4 grid, whilst taking account of whether these objects are visible to a confederate who instructs the participant - to investigate impairments in ToM in 209 participants (age: M = 37.8, SD=13.6; 56% female). Participants were divided into a) developmental trauma-positive (DT+) and control groups (DT-) based on their history of developmental trauma and b) then further into subclinical (S) and healthy groups (H) as based on psychotic experiences indexed by the CAPE-P15. After exclusion, the numbers in each group were: DT+H (47), DT+S (84), DT-H (54), DT-S (12). (Total: 197). RESULTS: Developmental trauma exposure was associated with psychotic experiences (OR: 7.89, p < .001), which remained significant after controlling for demographic and clinical confounds (adjusted R2 = 0.452, R2 change = 0.0184, p = .009). Participants with developmental trauma (F1, 194) = 5.46, p = .020, ηp2 = 0.027) and participants more prone to psychotic experiences (F1, 194) = 4.71, p = .031, ηp2 = 0.024) demonstrated significantly lower accuracy on the Director task relative to their respective control, after controlling for the effects of age. CONCLUSIONS: ToM deficits are associated with self-reported developmental trauma and psychotic experiences. Further work is needed to explore these relationships further and whether they represent generalised or specific effect effects on developmental trauma and psychopathological domains.