Chronic antidepressant counteracts the conditioned analgesia induced by a context previously associated with inescapable shock.

Rats exposed to a context previously paired with an inescapable shock session showed an increase in the paw lick and escape latencies in the hotplate test. This analgesic response was clearly reversed following chronic antidepressant drug administration. These findings indicate that chronic antidepressant treatment can influence the biological processes involved in the inescapable shock-induced conditioned analgesia.