Susceptibility to Post Traumatic Stress Disorder (PTSD) varies considerably. As in Chronic Pain (Medical Litigation News Volume 3, Issue 9), the claimant's premorbid psychological profile should be defined in the medicolegal process.
As well as genetic and personality factors and psychopathology in the family[1], a significant component of the "thin skull" for PTSD in women is childhood sexual abuse. Severity of PTSD symptoms is increased if the sexual abuse included multiple episodes involving sexual intercourse[2].
PRACTICE POINT Specifically ask psychiatric/psychological expert witnesses to match the claimant to the characteristic psychological profile |
CorticoTrophin Releasing Factor (CTRF) produced in the pituitary gland has been shown to be the dominant hormone mediating stress in mammals. As CTRF activity has also now been shown to be increased in PTSD[3], it may prove to be a major chemical mechanism for vulnerability to the Disorder.
PRACTICE POINT Hormone disturbances are being identified experimentally, but are not yet ready for routine diagnostic testing |
Naturally-occuring narcotic pain-killer (endorphin) concentrations in the (cerebrospinal) fluid surrounding the brain were increased in PTSD patients compared with controls[4]. It remains to be shown whether this response is a marker for vulnerability and therefore antedates the stress. The observed inverse relationship with avoidant and intrusive symptoms suggest that is instead an adaptive response to the trauma.
Single Photon Emission Computed Tomography (SPECT, see Medical Litigation News Volume 1, Issue 3) shows nonspecifically diminished regional blood flow to the frontal lobes and selective reduction in flow to the caudate nuclei in the base of the brain[5].
PRACTICE POINT Characteristic disturbances of regional Cerebral Blood Flow can be seen on SPECT scanning |
PTSD may disturb production of the neurotransmitter (brain hormone) Serotonin[6], for which antidepressant medications such as Prozac are specifically tailored.
Trials of antidepressant medications have shown varying success[1]. Moclobemide, a relatively new member of a different family of antidepressants (MAOI), has shown encouraging benefit in a small study[7] and will be moving on to double-blind controlled trial.
PRACTICE POINT Although response to antidepressant medication is variable, individual and certain families of drugs are showing promise |
Benefit can be expected from the proven behavioural therapies known as systematic desensitisation and flooding.
Prognosis is influenced by not only the severity of the traumatic event but also the occurrence of dissociative symptoms during the ordeal, and the client’s coping strategies and social supports[1].
PRACTICE POINT Obtain for expert review the pre-injury primary care and psychiatric records to characterise vulnerability and increase prognostic accuracy |
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