Individuals with higher loneliness reported shorter sleep duration at higher levels of avoidant attachment, though this was the only significant attachment × loneliness interaction found across sleep outcomes, and the effect was small in magnitude.
Key Findings
Results
Higher loneliness was associated with shorter sleep duration specifically at higher levels of avoidant attachment.
This was identified using ordinal logistic regression with attachment dimensions, loneliness, and their interactions as independent variables
The interaction remained significant after correction for multiple testing
The finding was replicated in a sensitivity analysis excluding participants who reported sleeping more than nine hours
The authors describe the moderation effect as 'small in magnitude'
Results
Attachment × loneliness interactions were not observed for sleep quality, sleep onset latency, or wake after sleep onset.
Four sleep outcomes were examined: sleep duration, sleep quality, time to fall asleep, and wake after sleep onset
The avoidant attachment × loneliness interaction for sleep duration was the only significant interaction in the adjusted models
Attachment anxiety did not significantly moderate the association between loneliness and any sleep outcome
The lack of significant interactions across most outcomes constitutes 'limited evidence' according to the authors
Methods
The study used a large secondary dataset of UK adults with no health conditions or impairments, drawn from the Touch Test Study.
The original sample consisted of N = 15,049 adult participants from the UK
The final analytic sample ranged from N = 11,901 to N = 11,916 across different sleep outcomes
Participants were originally recruited through opportunity sampling for a study measuring outcomes and attitudes towards touch
Individuals with health conditions or impairments were excluded from the analytic sample
Background
Attachment dimensions and loneliness have independently been associated with sleep outcomes prior to this study.
Lower attachment insecurity is generally related to better sleep
Lower loneliness is generally related to better sleep
Whether attachment dimensions and loneliness interact in relation to sleep had remained unclear before this study
The study was designed specifically to examine whether attachment anxiety and attachment avoidance moderated associations between loneliness and sleep outcomes
Conclusions
The authors concluded that attachment and loneliness may be relevant relational factors in sleep research, but the observed moderation effect was specific to sleep duration and small.
Avoidant attachment moderated the loneliness–sleep duration relationship while anxious attachment did not moderate any sleep outcome
The specificity of the effect to sleep duration (and not quality, onset, or wake after sleep onset) limits broader generalization
The authors used the phrase 'limited evidence' to characterize the overall pattern of findings
Both attachment and loneliness were framed as potentially relevant relational factors warranting further investigation in sleep research
What This Means
This research suggests that the relationship between loneliness and sleep is not the same for everyone — it may depend on a person's attachment style, particularly how avoidant they are in close relationships. Using data from over 11,000 UK adults, the study found that people who are both lonelier and more avoidant in their relationships (meaning they tend to be uncomfortable with closeness and prefer emotional distance) reported shorter sleep duration. This pattern held up even after accounting for other factors and applying statistical safeguards. Importantly, this interaction was not found for other aspects of sleep, such as sleep quality, how long it takes to fall asleep, or how often people wake up during the night.
The study did not find that anxious attachment — a style characterized by worry about relationships and fear of abandonment — changed how loneliness related to any sleep outcome. This suggests the way loneliness connects to sleep may be specifically tied to avoidant tendencies rather than relationship anxiety. However, the researchers caution that the effect they found was small and limited to sleep duration only, so it should not be overstated.
This research suggests that how people relate to others in close relationships, and how connected or isolated they feel, may both play a role in sleep health. Understanding these relational factors could be relevant for researchers and clinicians thinking about why some people sleep differently than others, though the findings here are preliminary and the effect sizes are modest. Future research with objective sleep measures and more diverse samples would help clarify these relationships.
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Samii J, Vafeiadou A, Rowe A, Kent C, Banissy M. (2026). Adult attachment, loneliness, and self-reported sleep outcomes: A secondary analysis of the Touch Test Study.. PloS one. https://doi.org/10.1371/journal.pone.0356812