Are lorazepam-induced deficits in attention similar to those resulting from aging?

The purpose of this experiment was to compare, in three tasks of attention, the impairment caused by lorazepam (1 and 2.5 mg) administered to young vo lunteers with the impairment that results from aging. Performance on digit cancellation (DC), digit-symbol substitution (DSS), and Paced Auditory Seri al Addition Task (PASAT) was significantly impaired by lorazepam (2.5 mg) a nd was significantly worse in the middle-aged group (mean +/- SEM, aged 58. 9 +/- 0.8 years) compared with the younger, IQ-matched group (20.7 +/- 0.2 years). However, there were interesting differences in the extent of impair ments among the three tests. In the DC test, lorazepam (2.5 mg) produced a significantly greater impairment than was seen in either the middle-aged me n or middle-aged women. However, in the DSS test, the middle-aged women wer e significantly more impaired than either the middle-aged men or the young volunteers tested after lorazepam (2.5 mg). In the PASAT, both the lorazepa m (2.5 mg) group and the middle-aged women were more impaired than the midd le-aged men. These results raise the important possibility of gender differ ences in age-related decline of attentional processes.