This article summarizes the research literature documenting the high prevalence of psychological trauma, including childhood sexual and physical abuse, among people diagnosed psychotic in general and schizophrenic in particular. A review of the relevant literature indicates that childhood trauma may in some cases be causally related to the development of psychotic symptomatology later in life, perhaps by contributing to the diathesis in the stress-diathesis equation. However it is argued that regardless of whether clinicians view the relationship as causal, contributory, co-morbid, or coincidental is irrelevant to the fact that this high prevalence dictates that all people diagnosed schizophrenic receive a proper trauma assessment and, where appropriate, be offered psychological treatments to address the sequelae of the trauma or abuse. Taken in conjunction with the proven effectiveness of various psychological and psychosocial treatments in ameliorating the symptomatology and improving the quality of life of people diagnosed schizophrenic, the need to address the trauma found in such high rates in this population requires a broadening, and not as some suggest a limitation, of the range of treatments offered. The authors identify and challenge ideologically, rather than empirically, driven assumptions about the etiology of schizophrenia, particularly the distorted but dominant version of the diathesis-stress model, which claims that the diathesis is predominantly or exclusively biogenetic in origin and therefore inaccurately places all psychosocial stressors and traumas exclusively on the stress side of the equation. It is this bias that inhibits many clinicians from taking trauma histories with people diagnosed schizophrenic and from offering appropriate treatment when trauma is disclosed. It is the same bias that leads some to argue for a reduction in the availability of psychological therapies for such people.