Abstract
Evidence of efficacy in studies of post-traumatic conditions is largely derived from studies in which variables are kept to a minimum. Extrapolation of treatments from uncomplicated disorders to complex conditions may therefore be called evidence-based without being evidenced. Complex conditions with polysymptomatic presentations and extensive comorbidity are being denied proper evaluation, and patients most severely traumatised from the early stages of their development are not provided with rigorously evaluated psychotherapies because they are more difficult to study in the manner approved by research protocols. Such evidence as there is suggests that the simple extension of treatments for uncomplicated disorders is seriously inadequate. This has significant implications for health services responsible for the provision of the most efficacious treatments to those whose disorders arise from severe trauma, often very early in their life.