Effects of marijuana extract distillate and cannabidiol on variable interval performance as a function of food deprivation.

Lever-pressing rates plotted as a function of number of hours of food deprivation produces an inverted U curve, the activation performance curve. Since delta 9-tetrahydrocannabinol depresses the response rate on variable interval (VI) performance, it may be that the response depression reflects changes in this curve. Rats were tested VI performance at five levels of food deprivation and were treated with a vehicle control, marijuana extract distillate (MED) at 7.5 and 11.25 mg/kg, cannabidiol (CBD), at 15 mg/kg or combinations: 7.5 mg/kg MED + 15 mg/kg CBD and 11.25 mg/kg MED + 15 mg/kg CBD. MED produced a depression of VI performance which was greatest at low levels of deprivation. CBD did not depress performance. When CBD was conbined with MED, potentiation of depression occurred. The potentiation depression was not additive, but occurred at high levels of deprivation. It appears that MED depresses performance most at low levels of deprivation and that CBD potentiates the depression produced by MED at high levels of deprivation.