Chronic mild stress-induced reductions in saccharin intake depend upon feeding status.

The consumption of a weak saccharin solution was examined in rats subjected to chronic mild stress (CMS). Intake of saccharin was reduced in stressed animals compared to isolated and group control animals but saccharin preference was not affected. Removal of water deprivation from the CMS schedule did not alter the effects of CMS upon saccharin intake. However, when food deprivation was omitted entirely from the CMS schedule the reduction in saccharin intake was eliminated. Similarly, in animals habituated to the full CMS procedure, reduction in saccharin intake was abolished by omitting food deprivation or by delaying the intake test for 24 h. Both CMS and food deprivation reduced water intake but had no effect on food consumed during the fluid-intake test. The presence of food deprivation during CMS appears to be a key factor affecting saccharin intake. Our data suggest that saccharin intake is not an appropriate measure of stress and anhedonia.