Craig M. Traub expands on four factors that often attribute to the contraction of DID. The four factors that Traub elaborates on are “childhood trauma, prevalence ratings, media influences, and psycho-physiological perspectives” (Traub, 2009). Given the large number of cases of DID patients enduring childhood abuse or trauma, advocates of DID may be jumping to it as a diagnosis upon learning about childhood trauma (Traub, 2009). Traub explains that in order to definitively link childhood trauma and DID, the reports of the abuse must be verified from some other source than the word of patient, because memory of past events are often “reconstructed ex post facto” (Traub, 2009). Next, Traub addresses the alarming sudden increase in the number of patients diagnosed with DID. While some argue that DID was simply not known previously, or that there was increase in childhood traumatization, the fact remains that only 14 cases of DID were reported between 1944 and 1969, but 40,000 cases were reported between 1985 and 1995 alone (Traub, 2009). Traub finally investigates physiological differences between those with DID and those without. EEG studies showed disparity between the alternate personalities within a single patient. Other studies also showed a difference in cerebral blood flow between the personalities. The results were not always the repeatable, however, and EEG scans have the possibility to be altered by forced concentration (Traub, 2009). Traub admits that although his studies shed more light on DID, and his research was relevant and insightful, the diagnostic categorization of DID remains inconclusive to this day (Traub,