To the Editor: In criticizing the acute stress disorder diagnosis, Dr. Marshall et al. justifiably echoed previously expressed concerns
+(1). We question the evidence on which some of their conclusions are based. The retrospective studies of acute trauma reactions that they cite are flawed because mood-related memory bias renders questionable the accuracy of retrospective reports. Moreover, only one of the three prospective studies referred to employed a validated diagnostic measure of acute stress disorder
+(2). The authors did not cite four key prospective studies that found that between 78% and 83% of individuals with acute stress disorder subsequently developed PTSD
+(3–
+5; Brewin et al., 1999). The evidence indicates that the acute stress disorder diagnosis can identify a significant proportion of acutely traumatized individuals who develop PTSD. This is a useful development because early intervention with those diagnosed as having acute stress disorder can prevent the development of PTSD
+(6).