Information processing deficits in withdrawing alcoholics

Prepulse inhibition (PPI) of the acoustic startle response (a reduction in response to an intense, startling stimulus (the pulse) if preceded by 30-15 0 ms by a weaker, non-startling stimulus) is an established model to index information processing deficits in thought-disordered schizophrenic patient s. The present study aimed to investigate the influence of alcohol withdraw al on the PPI effect. Eight withdrawing alcoholic patients underwent testin g for PPI of the acoustic startle response (defined as percentage reduction of the response over pulse-alone stimulus; prepulses 15 dB above the backg round) on three occasions (1, 3 and 7 days following the last drink). The r esults demonstrated remarkably low levels of PPI on days 1 and 3, with this being very robust in three patients who had a history of delirium tremens; there was a trend towards normalization of PPI on day 7. This study, altho ugh preliminary, suggests strongly that there is a deficit in the filtering of sensory information in alcohol-dependent patients undergoing alcohol wi thdrawal. This was most apparent in those with a history of delirium tremen s. Further studies are needed to define the cause and chronicity of these d eficits.