Chronotype and time-of-day effects on mood during school day

Area of Science:

• Chronobiology
• Adolescent Psychology
• Sleep Science

Background:

• Existing research indicates a link between mood, time of day, and morningness-eveningness (M-E).
• Studies on adolescents are limited, necessitating further investigation into daily mood fluctuations within this demographic.
• Understanding these relationships is crucial for supporting adolescent well-being during the school day.

Purpose of the Study:

• To analyze daily mood fluctuations in adolescents within a naturalistic school setting.
• To investigate the relationship between chronotype (M-E preference), time of day, and mood during the school schedule.
• To determine if sleep duration influences the connection between chronotype and mood.

Main Methods:

• A sample of 655 adolescents (aged 12-16) participated in the study.
• Mood levels (pleasantness) were assessed three times daily during school hours (morning, midday, afternoon).
• Participants also reported their M-E preference and time in bed.

Main Results:

• Mood generally increased throughout the school day, irrespective of chronotype.
• Morning types reported better mood compared to other chronotypes.
• Evening types exhibited the lowest mood levels, and this was not explained by shorter sleep duration.

Conclusions:

• Adolescent mood naturally improves as the school day progresses.
• Morning-oriented adolescents tend to have better moods than evening-oriented peers.
• Shortened sleep duration does not appear to be the primary cause of lower mood in evening-oriented adolescents.