182. An “antidepressant”

54s

BIOLPSYCHIATRY 1998;43:1S-133S

=56.3t14.5; controls =25.5*7.3, p=0.001; FTSD Beck Depression Inventory=29.1* 15.8;controls=2.2* 2.6,p= O.001).Binaurrdpresentation of 60 stimulieach of 60, 70, 80, 90 and 100dBin randomorder were administeredthrough headphones.EEG epochs containingthe evokedresponseswere averagedatler epochs containingartifact were excluded.AEPamplitudes,measuredmarmafly,wereplottedagainstthe intensities,and slopes were calculatedusing the least squaresmethod. We foundno differencebetweenthe PTSDand controlgroupsin AEP amplitudeor the AA slopes: both groups had primarilypositive AA slopes.Differencesbetweenthe findingsin this studyand those previouslyreportedmay relate to state-traitfactors.Becausethe AEPsvary with central serotonirractivities,SSRIpharmacotherapymay normalize abnormalsensoryprocessingin P’T.SD.

Thursday Abstracts

sponses (SCR) in 19 Vietnam veterans with Y1’SDand 20 normal comparisonsubjects in an auditory classical conditioningparadigm. Subjectsheard severaldifferent70dBtones throughheadphonesduring habituation.During20 conditioningtrials, the unconditionedstimulus (1OWB)was paired with one of the original tones (CS) for six presentations.Then the CS was presentedafone 12 times during the extinction phase. Results showed equivalent patterns of acquisition across groups but delayed and inconsistentextinction among PTSD patients.Significantlymore PTSDthan controlsubjectsfailed to reach the criterionfor extinction(X2 (1)=3.7, p