Emotional states in adolescents: time of day X chronotype effects while controlling for psychopathological symptoms and sleep variables

The current study was developed under the larger research project True Times - Morningness-eveningness and time-of-day effects on cognitive performances and emotional states: New lessons from children and adolescents- PTDC/PSI-ESP/32581/2017 and CENTRO-01-0145-FEDER-032581.The present study primarily aimed to investigate the interactive effect of chronotype and time of day on adolescent’s emotional states. Chronotype influences behaviour throughout the day, with variables such as mood exhibiting circadian rhythmicity. We also considered the influence of potential covariates, such as sleep variables and psychopathological symptoms. A total of 190 8th-grade students (53.7% males; mean age 13.47 ±.70) completed a two-part protocol: part one probing sleep (BaSIQS), chronotype (CSM), and psychopathological symptoms (SDQ); part two targeting emotional states (FS; STAIC-S; EAPNC), while manipulating the time of day (first and last hours of the school day). The hypothesized interaction failed to reach significance, despite correlational analyses and visual inspection of mean values suggesting some interactive effects. Time of day independently impacted positive emotional states, rising from morning to afternoon, and anxiety-state, which dropped. Chronotype independently influenced momentary mood (non-significant when sleep and psychopathological symptoms were controlled for), positive affect (non-significant when controlling for psychopathological symptoms), and anxiety (non-significant when sleep quality and psychopathological symptoms were controlled for). There were consistent effects of time of day, but its interaction with chronotype did not reach significance. Some associations between chronotype and emotional states seemed to be influenced by sleep and/or psychopathological symptoms.This work was supported by the European Regional Development Fund - FEDER [CENTRO-01-0145-FEDER-032581], through the program Portugal-2020 (PT2020) and the Regional Operational Programme in the Center, and the Portuguese Foundation for Science and Technology FCT - I.P./MCTES through national funds (PIDDAC) [PTDC/PSI-ESP/32581/2017]