HCRT and insomnia measurement: Data such as these support the hypothesis that insomnia can be due to an inability of the brain to switch off wake-promoting systems such as the orexin system, as well as an inability to switch on sleep-promoting circuits with an instability of the flip-flop switch system (Palagini et al., 2023a; Plante et al., 2012; Palagini and Bianchini, 2022; Tang et al., 2017).