Platelet monoamine oxidase activity, ego strength, and neuroticism in soldiers with combat-related current posttraumatic stress disorder.

AIM To assess possible differences in platelet monoamino oxidase-B (MAO-B) activity, ego strength, and neuroticism in combat-experienced soldiers with or without current posttraumatic stress disorder (PTSD). METHOD The soldiers with current PTSD (N=36) and a control group of 34 healthy soldiers were matched in combat experience, time passed between combat experience and the study, demographic variables (age, marital status, education), and smoking status. Platelet MAO-B was assayed fluorometrically, ego strength was measured by the Croatian version of the Ego Identity Scale, and neuroticism by the N-scale from Eysenck's EPQ-R questionnaire. RESULTS Soldiers with combat-related current PTSD had lower platelet MAO-B activity than the control group (9.1+/-3.9 vs. 11.9+/-4.0; p<0.05), as well as lower ego-strength (86.3+/-8.3 vs. 108.6+/-13.4; p<0.05) and higher neuroticism (23.5+/-13.2 vs. 5. 9+/-4.7; p<0.05). There was no association of ego strength or neuroticism with platelet MAO-B activity. CONCLUSION Ego identity strength and emotional stability are associated with successful coping with combat trauma. The involvement of platelet MAO-B activity in biological basis of ego strength and neuroticism could not be demonstrated.