Quality, Not Duration, Suggested as Optimal Intervention in Adolescent Sleep Health

Quality, as opposed to duration, was suggested as the optimal target for prevention and intervention in sleep health among adolescents, with potential efficacy cited in improving psychological functioning, according to study findings published in The Journal of Child Psychology and Psychiatry.

The impact of sleep duration on the psychological functioning of adolescents has been cited in a previous study as contributing to higher rates of depression, anxiety, impulsive behavior, and impaired cognitive performance. However, the researchers of the current study highlight that causality remains a significant issue of contention, with sleep quality also proving a notable factor.

As the study authors note, sleep and psychological problems could have common underlying causes, such as shared environmental influences or common genetic factors. To overcome this potential conflict, they analyzed twins, because prior twin studies on adults have shown that overlapping genes influence the association between sleep disturbances and anxiety, depression, and externalizing behaviors.

The researchers conducted a cross-sectional analysis on monozygotic twin pairs (n = 12,803; aged, 13-20 years; 42% male), utilizing a longitudinal discordant monozygotic co-twin design that classified twins as concordant or discordant for sleep duration and trouble sleeping.

“This design can evaluate whether monozygotic twin pairs differ and change over time with respect to sleep and psychological functioning,” explained the study authors. “Because monozygotic twins are genetically identical and growing up in the same family, the design enables [us] to rule out genetic and shared environmental influences when evaluating whether the duration and quality of sleep contribute to internalizing problems, externalizing problems, and subjective well-being.”

The causal effect of both sleep duration and quality on psychological functioning of adolescents served as the primary focus of the study, in which participants completed questionnaires on sleep and psychological functioning consistently over a 2-year interval. Concordant and discordant subgroups were compared regarding internalizing problems, externalizing problems, and subjective well-being.

In the study, impaired psychological functioning was associated with both short sleep and problematic sleep. After conducting a longitudinal analysis, the researchers found that an increase in sleep problems led to a significant increase of 52% in internalizing problem scores and 25% in externalizing problem scores compared with co-twins who remained without sleep problems (3% increase and 5% decrease, respectively). Conversely, psychological functioning did not worsen with decreasing sleep duration, highlighting the potential significance of sleep quality.

“We moreover found support for a bidirectional association between psychological functioning and sleep problems,” concluded the study authors. “Nevertheless, the findings suggest that interventions that primarily target sleep problems rather than sleep duration might be most effective in preventing emotional and behavioral problems in adolescents.”

Reference

Vermeulen MCM, Heijden KBVD, Kocevska D, et al. Associations of sleep with psychological problems and well-being in adolescence: causality or common genetic predispositions? J Child Psychol Psychiatr. Published online May 12, 2020. doi:10.1111/jcpp.13238