M98. IS THERE A DEVELOPMENTAL TRAUMAGENIC PHENOTYPE OF PSYCHOSIS?
Authors: Bloomfield Michael , Modaffar Mustapha , Onyeama Franca , Chang Ting-Yun , Dickson Joseph , Billings Jo 
Published: May 2020

Abstract

Background
Developmental trauma (DT) induces vulnerability to psychosis in adulthood. Adult survivors of DT with psychosis (ASDTP) have worse prognosis across a range of outcomes compared to individuals with psychosis without DT exposure. It has been suggested that this may reflect a developmental ‘traumatogenic’ psychosis phenotype, distinct from idiopathic schizophrenia. Given the implications for precision medicine, we therefore sought to test this hypothesis by conducting systematic reviews and meta-analyses of the literature comparing psychotic symptoms and neuroimaging findings between adults with psychosis diagnoses with and without developmental trauma.

Methods
We registered our search protocols in PROSPERO (CRD42018105021 and CRD42019131245). We systematically searched literature databases for relevant studies published up to July 2019. “Embase”, “MEDLINE”, and “PsychINFO” were systematically searched. Reference lists, OpenGrey, and Google scholar were hand-searched. Phenomenological outcomes of interests were quantitative and/or qualitative differences in psychotic symptom expression (primary outcome) and other domains of psychopathology (secondary outcome) between ASDTP and people with psychosis who did not report developmental trauma. Neuroimaging outcomes of interest including markers of brain volume and function (e.g. task-induced blood-oxygen dependent signal).

Results
Seventeen studies of symptomatology were included. Of these, four were meta-analysed. There was a relationship between DT and greater positive (Hedges g=0.53; p&lt;0.001) and negative (Hedges g =0.41; p=0.001) symptom severity. ASDTP had greater neurocognitive deficits and symptom severity in other domains of psychopathology compared to individuals without DT. There was evidence that psychotic symptom content related to traumatic memories in those with experiences of DT. We identified twenty-seven imaging studies (n = 1,438 psychosis patients, n = 1,114 healthy controls or healthy siblings). DT was associated with global and regional differences in grey matter; corticolimbic structural dysconnectivity; a potentiated threat detection system; dysfunction in regions associated with mentalization; and elevated striatal dopamine synthesis capacity. Meta-analysis indicated that developmental trauma is associated with reductions of cortical thickness, global grey matter volume, and hippocampal volumes in patients with psychosis.

Discussion
Adult survivors of developmental trauma have more severe psychotic symptoms than those without developmental trauma histories. Alongside findings of differences in symptom expression and neuroimaging, the evidence suggests that there may be developmental traumatogenic psychosis phenotype. However, a key mechanistic gap remains how clinical and neuroimaging findings relate to each other. Nonetheless, alternative interpretations, such as an underdiagnosis of post-traumatic stress disorder, could also be plausible. These findings warrant further research to elucidate vulnerability and resilience mechanisms for psychosis in adult survivors of developmental trauma.