Lj. Metzger et al., AUDITORY EVENT-RELATED POTENTIALS TO TONE STIMULI IN COMBAT-RELATED POSTTRAUMATIC-STRESS-DISORDER, Biological psychiatry, 42(11), 1997, pp. 1006-1015
This study attempted to replicate findings of abnormal auditory event-
related potentials (ERPs) in posttraumatic stress disorder (PTSD) in a
sample of Vietnam combat veterans, Veterans with combat-related PTSD,
divided into unmedicated (unmed-PTSD, n = 12) and medicated (med-PTSD
, n = 22) groups, and veterans without PTSD (non-PTSD, n = 10) complet
ed a three-tone ''oddball'' target detection task while ERPs were meas
ured. Individuals with comorbid panic disorder (PD) were excluded from
the primary analyses. Parietal P3 amplitude to the target tone was si
gnificantly smaller in unmed-PTSD compared to med-PTSD and non-PTSD gr
oups. These differences did not remain significant when an adjustment
was made for level of depression. Parietal P3 amplitude was also negat
ively correlated with state anxiety. Secondary analyses within the unm
ed-PTSD group indicated that participants with comorbid PD (n = 3) had
the largest parietal P3 amplitudes to target tones. Results are consi
stent with attentional or concentration deficits in PTSD and highlight
the importance of considering comorbid diagnoses, The absence of ERP
differences between med-PTSD and non-PTSD participants suggests that p
sychotropic medication may normalize these deficits. (C) 1997 Society
of Biological Psychiatry.