Tonic immobility among survivors of sexual assault.

While tonic immobility (TI) is a phenomenon well known and documented in the animal world, far less is known about its manifestation in humans. Available literature demonstrates that TI is significantly associated with less hopeful prognoses when compared with survivors who did not experience TI (Fiszman et al., 2008; Heidt et al., 2005). If survivors who experience TI are at increased risk for "depression, anxiety, posttraumatic stress disorder (PTSD), and peritraumatic dissociation" (Heidt et al., 2005, p. 1166) and respond more poorly "to standard pharmacological treatment for PTSD" (Fiszman et al., 2008, p. 196), the implications for treatment are significant, suggesting that TI "should be routinely assessed in traumatized patients" (Fiszman et al., 2008, p. 193). Literature indicates that "TI is thought to be particularly relevant to survivors of rape and other sexual assault" and that "sexual assault is a trauma that appears to entail virtually all of the salient elements associated with the induction of TI in nonhuman animals, namely, fear, contact, and restraint" (Marx et al., 2008, p. 79). Describing the phenomenon as it is experienced by survivors is especially important because the ability to accurately understand and describe the nature of the phenomenon is the first step toward accurately identifying, diagnosing, and treating the sequelae of such a response. This study examines the experience of TI from the perspective of 7 women who survived a sexual assault accompanied by tonic immobility using qualitative phenomenological methodology, and yields a description of the core defining themes of the experience of TI.