Distinction of normal, depressed and PTSD phenotypes.

<p>(A) Normal, depressed and PTSD patients are distinguished in the stress-feedback-period parameter space. All three categories can be clearly distinguished with PTSD having a strong negative feedback (low K values). (B) Normal, depressed, and PTSD patients are distinguished in the stress-feedback-cortisol (nadir) concentration space. The cortisol concentration is found to be lower for PTSD, with low K (strong feedback) values in comparison to the normal. In (A) and (B), clearly the transition from Normal PTSD (moving towards low K in (A), low cortisol values in (B)), Normal Depression (moving towards high K values, high cortisol values), and Depression PTSD (moving towards a low K, low cortisol values) can also be distinguished. PTSD depression (moving towards a high K, high cortisol values) can also be distinguished.