Desmethylimipramine (DMI) counteracts learned helplessness in rats.

In a study of the mechanisms controlling the learned helplessness phenomenon, rats were exposed to either inescapable preshocks or control procedures, treated with one of three dosages of desmethylimipramine, and tested for later adaptive responding. This catecholamine modulator attenuated the deficits in escape responding that ordinarily follow prior exposure to inescapable preshocks, and it did so in a dose-dependent fashion. These findings support the position that the learned helplessness phenomenon is mediated by catecholamine changes.