Flight fight and freeze, why you should know about the freeze response

PTSD treatment

Why should you know about the freeze response?

1.   The freeze response (tonic immobility) is common amongst PTSD sufferers who have been sexually assaulted
2.   When tonic immobility has been present during trauma, medications may not be effective

In a recent study published in Acta Obstetricia et Gynecologica Scandinavica on June 7 2017, the authors reported that tonic immobility during sexual assault was associated with the development of post-traumatic stress disorder and severe depression. They reported that just over half (51%) of the women who experienced tonic immobility developed PTSD compared with 28% of women who did not experience it, even after adjusting for a prior diagnosis of PTSD and related risk factors.

Lima et al 2010 examined the outcomes of pharmacotherapy as a treatment for PTSD where (i) tonic immobility (ii) peritraumatic panic or (iii) dissociation were present during the trauma.  Lima eta al 2010 concluded that pharmacotherapy was least effective amongst those who experienced tonic immobility.

Clinical Considerations

  • It is useful to ask your client about the presence of tonic immobility during trauma, for example ask “did you freeze during the trauma?”
  • Psychoeducation about tonic immobility may be helpful for clients who report this experience. For example “tonic immobility is a common but involuntary response to inescapable life-threatening events”
  • If clients report having experienced tonic immobility and also state they have only tried medication and that “nothing has worked”, it may be useful to refer to the research by Lima et al 2010 .

( The best treatment for PTSD )

Tonic Immobility, Dissociation, Depersonalisation and Derealisation – DEFINED

Tonic immobility is a temporary state of motor inhibition. It is considered last-ditch of defence method, that occurs in situations involving extreme fear. Tonic immobility is an involuntary defensive strategy.

Dissociation is a detachment from reality, it is a mental process where a person disconnects from their thoughts, feelings, memories or sense of identity. Depersonalisation and Derealisation are common forms of this in PTSD, and both these and more extreme forms where one has amnesia about traumatic events can occur at the same time at Tonic immobility, or Tonic immobility can occur on its own.

Depersonalization involves persistent or recurrent experiences of feeling detached from, and as if one were an outside observer of, one’s mental processes or body (e.g., feeling as though one were in a dream; feeling a sense of unreality of self or body or of time moving slowly).

Derealization involves persistent or recurrent experiences of unreality of surroundings (e.g., the world around the individual is experienced as unreal, dreamlike, distant, or distorted).


Lima, A. A., Fiszman, A., Marques-Portella, C., Mendlowicz, M. V., Coutinho, E. S. F., Maia, D. C. B., . . . Figueira, I. (2010). The impact of tonic immobility reaction on the prognosis of posttraumatic stress disorder. J Psychiatr Res, 44(4), 224-228. doi: 10.1016/j.jpsychires.2009.08.005

Möller, A., Söndergaard, H. P., & Helström, L. (2017). Tonic immobility during sexual assault – a common reaction predicting post-traumatic stress disorder and severe depression. Acta Obstetricia Et Gynecologica Scandinavica, doi:http://dx.doi.org/10.1111/aogs.13174

Volchan, E., Souza, G. G., Franklin, C. M., Norte, C. E., Rocha-Rego, V., Oliveira, J. M., . . . Figueira, I. (2011). Is there tonic immobility in humans? biological evidence from victims of traumatic stress. Biological Psychology, 88(1), 13-19. doi:http://dx.doi.org/10.1016/j.biopsycho.2011.06.002