Being a victim of circumstances beyond one's control has often been presumed as the necessary prerequisite to PTSD among therapists. One of the major implications of the existence of Perpetration-Inducted Traumatic Stress (PITS) is that it is necessary to include active participation in traumatic circumstances as another etiological mechanism. It is one that seems to lead to more severe aftermath, with some differences in pattern—not enough to establish it as a different phenomenon from PTSD, but differences with which therapists should be familiar.
Both Haley (1974) and Shatan (1978) have pointed out that when patients report having committed atrocities, the therapists have more trouble listening. Killing which does not fit the category of “atrocities” may well have the same problem. The very element of the diagnosis itself can be impacted: “there are many parallels in the experiences and behavior of those labeled as suffering from post-traumatic stress disorder and those with personality disorder label, although the two groups are perceived very differently by professionals. The major common factor, however, may be different manifestations of PTSD” (Hodge, 1997). Therapists who want to do the best work for their clients must have the knowledge that killing is a stressor with certain common features in its psychological aftermath (violent outbursts, intrusive imagery, perhaps a sense of disintegration).
Any differences in what constitutes effective treatment need to be understood. For example, Foa and Meadows (1997) note one treatment that might differ: