The serotonin transporter 5-HTTLPR polymorphism in the association between sleep quality and affect

Area of Science:

• Neuroscience
• Genetics
• Psychology

Background:

• A well-established link exists between sleep and emotional state (affect).
• Serotonin (5-HT) is crucial for regulating both sleep and mood.
• The serotonin transporter gene (5-HTTLPR) polymorphism influences serotonergic activity.

Purpose of the Study:

• To investigate if 5-HTTLPR genetic variation moderates the relationship between subjective sleep quality and next-day affect.
• To explore the role of serotonin in sleep and affect regulation.

Main Methods:

• Utilized a population-based sample of 361 ethnically homogenous adult female twins.
• Employed a five-day experience sampling method (ESM) protocol.
• Repeatedly assessed momentary negative affect, positive affect, and subjective sleep quality.

Main Results:

• A significant interaction was found between sleep quality and 5-HTTLPR genotype in predicting positive affect.
• Carriers of at least one S-allele showed a stronger association between sleep quality and positive affect compared to homozygous LL carriers.
• These findings suggest the S-allele of 5-HTTLPR amplifies the impact of sleep quality on subsequent positive affect.

Conclusions:

• The association between subjective sleep quality and positive affect is moderated by 5-HTTLPR genotype.
• Serotonin likely plays a role in the interplay between sleep and affect regulation.
• Results are preliminary and necessitate replication in larger, diverse cohorts.