The effects of severe sleep deprivation and subsequent recovery sleep on anxiety

Large-Scale Combat Operations (LSCOs) often involve severe sleep loss. To date, there has been little work on the extent to which anxiety is impacted by these conditions, and the rate at which recovery sleep reverses these effects. The aim of this study was to assess variations in anxiety across two consecutive nights of total sleep deprivation (TSD) and following one night of recovery sleep. Twenty-one healthy adults ranging from 18-33 years of age participated. Self-reported state anxiety was assessed using the Spielberger State Trait Anxiety Inventory (STAI-S). The STAI-S was administered at 1000, 1300, and 1600 over four days: 1) Baseline: day following one night of 8 hours time-in-bed (TIB), 2) TSD1: day following one night of TSD, 3) TSD2: day following two nights of TSD, 4) Recovery: day following 12 hours TIB after 62 hours of TSD. There was a significant main effect of Day, f(3,240) = 17.64, p < .0001. Post-hoc tests revealed that anxiety was significantly increased after one night of TSD compared to baseline and this further increased after two nights of TSD (p < .01). Anxiety level was restored to baseline following a single night of recovery sleep. These results demonstrate the adverse impact sleep loss has on state anxiety. Additionally, they also suggest that a single 12-hour TIB period is sufficient to reverse the adverse effect of acute, severe sleep deprivation on state anxiety - a finding that has implications for determining appropriate "recycle rates" (duration between missions) for Soldiers and others involved in continuous operations.