As with many disorders there is a formal set of diagnostic criteria for PTSD and symptom length of endurance and severity are weighed in as crucial to the diagnosis. (Vasterling & Brewin, 2005, p. 4) Neurobiological and Cognitive Effects

These outward symptoms and reports of the emotions that trigger them tend to be the most observable and therefore recorded aspects of the disease, yet it is also clear that much more is at work. A more modern take on PTSD, by the experts willing to look hard enough is that the traumatic event response may have to some degree created a neurobiological record creating in the brain a sort of hard wired response sequence for reacting to the event. Many experts now believe that it is these changes that create the enduring quality of the disiorder and make it much more difficult to treat than a simple short-term psychological reaction to witnessing or being involved in a traumatic event or events. (Vasterling & Brewin, 2005, p. 3)

There is a clear importance to note that observation is only a limited tool for diagnosing the severity of the disorder and understanding its enduring quality. When several sessions of cognitive or other psychological treatment fails to produce lasting results and appropriate responses to...

Researchers have done this with core diagnostic tools, such as functional MRI (fMRI) MRI and CT scan. These scans work to allow experts to compare a normal response to everyday stress or triggers to that of someone suffering PTSD and the results are often obvious. (Vasterling & Brewin, 2005, p. 64)
Conclusion

Recent and long-term research on PTSD has indicated behavioral and emotional reactions to PTSD are enduring in a great part because of the fact that there have been neurobiological changes in the brain of individuals who suffer from it. These changes cement the enduring quality of the disorder, and make it much more difficult to treat with simple cognitive or other non-pharmacological treatments. A better understanding of the neurobiological changes will likely lead to a greater emphasis on drug therapies and cognitive therapies that treat the disorder not as if it is all in ones' head or in their cognitive ability to control but as if it is an enduring biological reality that needs address to resolve.

References

Vasterling, J.J. & Brewin, C.R. (Eds.). (2005). Neuropsychology of PTSD: Biological, Cognitive, and Clinical Perspectives. New York: Guilford Press.