270. Donepezil augmentation for cognitive impairment in euthymic bipolar patients

administered lateral orbitofrontal rTMS to 7 subjects with GAD. On separate days, subjects received right or left high frequency, right or left low frequency, or placebo rTMS in a counterbalanced, single blind, randomized order. Serial self-rated visual analogue scales measuring anxiety and mood were performed. We hypothesized that right high frequency rTMS would increase anxiety whereas right low frequency rTMS would decrease anxiety based on: (1) data suggesting that the orbitofrontal cortex is important in anticipatory anxiety; (2) studies of healthy volunteers and depressed patients as well as a single case report in a GAD patient suggesting that high frequency prefrontal rTMS temporarily increases anxiety, and (3) the theory that high and low frequency rTMS may have opposite effects on brain function. Preliminary analysis reveals that placebo stimulation significantly decreased anxiety during the hour after stimulation. Also, relative to placebo stimulation, a trend exists suggesting that all the active stimulation types were anxiogenic. There did not appear to be a significant difference in anxiety ratings between the active stimulation cells. These results do not support our hypothesis. In fact, they suggest that single session lateral orbitofrontal stimulation may be anxiogenic, regardless of hemisphere or frequency. Pain with the active stimulation cells may have confounded our results.