Availability of learned helplessness test as a model of depression compared to a forced swimming test in rats

This study was designed to evaluate the antidepressant activity of various antidepressants using the learned helplessness test (LH) or the forced swim ming test (FS) in rats. Repeated treatment of the tricyclic antidepressants imipramine (10 mg/kg, p.o.), clomipramine (0.625 mg/kg, p.o.), amitriptyli ne (10 mg/kg, p.o.) and amoxapine (20 mg/kg, p.o.) reduced the number of es cape failures in the LH group, respectively. Repeated treatment of an atypi cal antidepressant, mianserin (2.5 and 5 mg/kg, p.o.), and one of the selec tive serotonin reuptake inhibitors (SSRI), fluvoxamine (1.25 mg/kg, p.o.), also reduced the number of escape failures in the LH group. In the FS, repe ated treatment of imipramine (5, 10 mg/kg, p.o.), amitriptyline (5, 10 mg/k g, p.o.) and mianserin (10 mg/kg) significantly decreased the duration of i mmobility time. On the other hand, repeated treatment of amoxapine (5-20 mg /kg), clomipramine (0.1325-1.25 mg/kg, p.o.) and fluvoxamine (0.3125-1.25 m g/kg, p.o.) failed to decrease the duration of immobility time in the FS gr oup. In conclusion, these results suggest that the LH group is sensitive to agents with a variety of antidepressant properties compared to the FS grou p in rats. Copyright 2001 (C) S. Karger AG, Basel.