Репозиторий Университета

© 2020 Elsevier Ltd Research on individual differences in the fields of chronobiology and chronopsychology mostly focuses on two – morning and evening – chronotypes. However, recent developments in these fields pointed at a possibility to extend chronotypology beyond just two chronotypes. We examined this possibility by implementing the Single-Item Chronotyping (SIC) as a method for self-identification of chronotype among six simple chart options illustrating the daily change in alertness level. Of 2283 survey participants, 2176 (95%) chose one of these options. Only 13% vs. 24% chose morning vs. evening type (a fall vs. a rise of alertness from morning to evening), while the majority of participants chose four other types (with a peak vs. a dip of alertness in the afternoon and with permanently high vs. low alertness levels throughout the day, 15% vs. 18% and 9% vs. 16%, respectively). The same 6 patterns of diurnal variation in sleepiness were yielded by principal component analysis of sleepiness curves. Six chronotypes were also validated against the assessments of sleep timing, excessive daytime sleepiness, and abilities to wake or sleep on demand at different times of the day. We concluded that the study results supported the feasibility of classification with the 6 options provided by the SIC.

© 2020 Elsevier Inc. Dysfunction in the circadian system has been linked to emotion regulation and mood disorders with genetic variation in clock genes as likely contributors. Here, we focused on endophenotypes of affective processing and investigated in two independent samples of healthy individuals (n1=99, n2=108) whether genotypes of a functional single nucleotide polymorphism (SNP) in the gene encoding CLOCK (CLOCK T3111C, rs1801260) differed in physiological responses to emotional stimuli. Both samples underwent an emotional startle paradigm with startle responses being measured via EMG. In the second sample, skin conductance responses as well as corrugator and zygomaticus activity were also assessed. In both samples, CLOCK T3111C was associated with overall startle responses to loud noise bursts with T/T homozygotes showing consistently more marked responses. However, in the all-female second sample, the effects of CLOCK on skin conductance responses to the same loud noise bursts depended on hormone status: similar to the startle results, in free-cycling women T/T homozygotes showed more pronounced skin conductance response (SCR) compared to C allele carriers. The opposite was true for women using combined oral contraceptives (COC). A further CLOCK × hormone status interaction effect was found for corrugator activity. In free-cycling women, T/T homozygotes presented with less corrugator activity to affective pictures compared to C allele carriers, while the opposite pattern emerged for COC users. The findings emphasize the potential role of CLOCK for affect and mood.

© 2020 Elsevier Inc. Dysfunction in the circadian system has been linked to emotion regulation and mood disorders with genetic variation in clock genes as likely contributors. Here, we focused on endophenotypes of affective processing and investigated in two independent samples of healthy individuals (n1=99, n2=108) whether genotypes of a functional single nucleotide polymorphism (SNP) in the gene encoding CLOCK (CLOCK T3111C, rs1801260) differed in physiological responses to emotional stimuli. Both samples underwent an emotional startle paradigm with startle responses being measured via EMG. In the second sample, skin conductance responses as well as corrugator and zygomaticus activity were also assessed. In both samples, CLOCK T3111C was associated with overall startle responses to loud noise bursts with T/T homozygotes showing consistently more marked responses. However, in the all-female second sample, the effects of CLOCK on skin conductance responses to the same loud noise bursts depended on hormone status: similar to the startle results, in free-cycling women T/T homozygotes showed more pronounced skin conductance response (SCR) compared to C allele carriers. The opposite was true for women using combined oral contraceptives (COC). A further CLOCK × hormone status interaction effect was found for corrugator activity. In free-cycling women, T/T homozygotes presented with less corrugator activity to affective pictures compared to C allele carriers, while the opposite pattern emerged for COC users. The findings emphasize the potential role of CLOCK for affect and mood.

© 2018, Media Sphera Publishing Group. All rights reserved.  Objective. To assess the prognostic significance of biological rhythms in depression on the example of the individual chronotype. Material and methods. One hundred patients (women 68%), aged 18—77 years, mean age 48±16, were examined before and after 8 weeks of treatment. The Morningness-Eveningness Questionnaire (MEQ) was used. Treatment response (a decrease of 50% in total MADRS scores to the 8 th week of treatment) and dynamics of depression severity (dMADRS; R) were assessed. Results and conclusion. Evening chronotype was found to be associated with poor prognosis. TCAs and SSRIs were more effective in eveningness, other antidepressants—in morningness. MEQ changes during and after treatment may reflect the resynchronizing activity of antidepressants.