Performance impairment consequent to sleep loss: determinants of resistance and susceptibility

Purpose of review Five years ago, it was first demonstrated that there are considerable, stable individual differences in performance impairment due to sleep deprivation. The discovery of this new phenotype, which has been labeled 'trototype', led to a surge of research activity aiming to identify predictors. Recent findings Genes involved in the adenosinergic and circadian regulation of sleep have been identified as candidate predictors of individuals' resistance or susceptibility to performance impairment resulting from sleep deprivation. Furthermore, brain regions potentially involved in the expression of individual differences in vulnerability to sleep loss have been found. This research has provided new insights into the mechanisms underlying sleep/wake regulation and responses to loss of sleep. To date, however, it remains unknown how much of the phenotypic variability is explained by any of the putative predictors of trototype. Summary The existence of substantial, phenotypic individual differences in performance impairment consequent to sleep loss has important implications for fatigue risk management in operational settings and for the symptomology and treatment of sleep disorders, putting a premium on the discovery of reliable predictors.