10. What are useful biomarkers?

No biomarkers are clinically useful or specific in diagnosing PTSD, assessing the risk of developing it, or charting its progression. Many biomarkers, however, are under study and they support a biologic basis of PTSD. Potential biomarkers currently under study include increased concentrations of corticotropin-releasing factor in the cerebrospinal fluid; low cortisol concentrations in the blood; measures of hyperarousal; delayed habituation to loud noises; panic attacks and flashbacks when noradrenergic systems are activated; alterations of brain structures, such as hyperactivation of the amygdala and hypoactivation of the prefrontal cortex when the person remembers trauma; and sleep disturbances, including nightmares of traumatic events. Reduced volume of the hippocampus might also be correlated with the development of PTSD. Preliminary evidence suggests that genetic factors might play a predisposing or modulating role in the development of PTSD.

American Psychiatric Association. 2000. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. Washington, DC: American Psychiatric Association.