Effect of diazepam on food consumption in rats.

Diazepam significantly increased milk consumption in rats that had never been exposed to this food before but not in rats trained to drink milk. Diazepam failed to increase lever-pressing for food reward except when this behavior had been previously suppressed by the simultaneous administration of electric shock. These data suggest that diazepam does not alter appetite, but enhances the expression of motivation suppressed by instinct or training.