This prospective, longitudinal study investigated risk factors in the devel
opment of psychological ill health and posttraumatic stress symptoms in a s
ample of 223 junior police officers. Participants were assessed using a sel
f-report methodology during training and again 12 months later on a range o
f personality, trauma exposure, and symptom measures. Risk factors for gene
ral psychological ill health at phase 2 of the research were found to compr
ise mostly stable, preexisting characteristics such as personality style, g
ender, and trait dissociation. Conversely, specific traumatic stress sympto
ms were more heavily influenced by experiences in the intervening 12 months
, such as severity of incident exposure and peritraumatic dissociation. The
implications for differential intervention are discussed.