0684 Effects of Transcranial Magnetic Stimulation (TMS) on Treatment of Intrusive Thinking in Insomniac Populations

Abstract Introduction Patients with clinical insomnia commonly report intrusive thinking (IT) as a common contributor to delayed sleep onset. Evidence suggests that the default mode network (DMN) may contribute this thinking. Therefore, we employed continuous theta burst (cTBS) repetitive transcranial magnetic stimulation (rTMS) modulate DMN activation, and thus reduce IT before sleep. Methods In counterbalanced cross-over design, active or sham cTBS was administered 20 participants insomnia, 8 males (Mage=31.63, SD=6.74) 12 females (Mage=23.75, SD=4.29), sessions separated by at least 5 days. To assess thoughts prior sleep, took Glasgow Content of Thoughts Inventory (GCTI). We utilized subscale GCTI measuring wakefulness. Higher scores indicate more persistent thoughts. conducted mixed ANOVA examine effects conditions on Results There medium effect size (ηp2 =.087) but no significant variance (p>.05) in average between (M=19.100, SD=5.349) (M=18.200, SD=4.502) Post-TMS sessions. interaction sex, TMS, administration (F(1,18)= 4.697; ηp2=.207; p=.044). then simple analysis females. condition reported post-TMS (F(1,7)= .628; ηp2=.082; p=.454). However, there for (F(1,11)= 5.894; ηp2=.349; p=.034). Post-hoc pairwise comparison revealed significantly greater (M=20.167, SD=5.68) compared pre-TMS (M=17.5, SD=5.73) during their session (p=.042). This not present (p>.05). Conclusion decrease relating wakefulness females, males, following TMS. Interestingly, also observed an increase condition, suggesting have developed expectations improvement been sensitized these cognitions when improved. These findings are encouraging improve IT, although preliminary data suggest differ Support (if any) W81XWH2010173