Table 1.

Evidence for altered noradrenergic function in PTSD^a

Physiological observations	Study results
Baseline/resting state measures
Increased resting heart rate and blood pressure	+/−
Increased resting urinary noradrenaline (norepinephrine) and adrenaline (epinephrine)	+
Decrease in basal and stimulated activity of cAMP	+/−
Decreased binding to platelet α2 receptors	+
Decrease in platelet MAO activity	+
Increased resting plasma noradrenaline or MHPG	+/−
Challenge test markers
Increased plasma noradrenaline with traumatic reminders/panic attacks	+
Increased heart rate and blood pressure response to traumatic reminders/panic attacks	+++
Increased orthostatic heart rate response to exercise	+
Increased symptoms, heart rate and plasma MHPG with yohimbine noradrenergic challenge	++
Differential brain metabolic response to yohimbine	+

^aThe evidence for altered noradrenergic functioning in PTSD is stronger in challenge test designs (i.e., incorporating threat responses, trauma reminders) in comparison to baseline/resting state studies

cAMP cyclic adenosine 3′5′-monophosphate, MAO monoamine oxidase, MHPG 3-methosy-4-hydroxyphenylglycol, PTSD post-traumatic stress disorder, +/− indicates an equal number of studies support this finding and do not support this finding, + indicates at least one study supports this finding and no studies do not support the finding, or the majority of studies support the finding, ++ indicates two or more studies support this finding, and no studies do not support the finding, +++ indicates three or more studies support this finding, and no studies do not support the finding