Chemosensory event-related potentials in alcoholism: a specific impairment for olfactory function.

Olfactory abilities are crucial in the development and maintenance of alcoholism, but while they have been widely explored in other psychiatric states, little is known concerning this sensorial modality among alcoholics. The present study explored the brain correlates of the olfaction deficit in alcoholism. Ten alcoholics and ten matched controls took part in psychophysical and electrophysiological olfactory testing. At behavioural level, we showed odor identification deficits in alcoholism, for orthonasal and retronasal testing. Electrophysiological data showed abnormalities (in latency and amplitude) for N1 and P2 olfactory components among alcoholics, which constitutes the first description of the cerebral correlates of olfactory impairments in alcoholism. This deficit appears associated with alterations in the brain structures responsible for the secondary, "cognitive" processing of odors. These results underline the need to take into account olfactory deficits in clinical practice and in studies exploring brain correlates of craving by means of alcohol odors.