120 patients were divided in experimental (depression-PTSD) and control (depression-only) group and evaluated using the following instruments: MADRS, HDRS-17 and QIDS-SR. The statistical analysis was performed by mean of Student t-test and Mann -Whitney U test.

Symptoms which differed most significantly between the two groups were: On MADRS instrument inner tension, sleep disturbances trouble concentrating, lassitude, inability to feel and pessimistic thoughts (p,0,001). On HDRS-17 instrument:: early, middle and late insomnia, agitation, work and activities (p < 0,001). On QIDS instrument: early, middle and late insomnia, concentration, interest and decision-making (p < 0,001).

The depression is accompanied by the increased activity of the brain centers engaged in the processing of emotional informations - the very regions that are “switched - off” in PTSD. Depressive symptoms comorbid to PTSD are not the results of the increased activation of the neural circuits by the two pathophysiological processes, but there is the case of differential engagement of neural networks in which stimulation from the lbrain structures responsible for generation of emotional input, increasingly arrives into the prefrontal brain structures, in which more intense and deeper emotional processing takes place causing more intense experience of emotional stimuli and bridging the connection from perceptual and cognitive contents up to affective and visceral centers of the organismus.