"A vivid example of traumatization-by-association is seen among
  females psychotherapist who've had intrusive memories and combat
  dreams after working with combat veteran patients. (I mention the
  gender of the therapists only to emphasize that they had never been
  near or shown much interest in combat.) Similar phenomena have been
  observed among male therapists working with female rape victims.
  Becoming intimately involved with another person's trauma can make
  it make it so real that it can become your own trauma as well. Thus
  the full array of primary trauma symptoms can develop in intimate
  listeners. These include the reexperiencing, the heightened arousal
  symptoms, the emotional numbing, and all the mechanisms people
  employ to deal with these symptoms."

  _Back from the Brink_
  Don R. Casserole, Ph.D. 1992 Bantam Books ISBN 0-553-08977-3