Sleep and Emotional Processes Show Connection in New Study

Variations in sleep and emotional processes are closely related, according to to a new study publlished in Journal of Sleep Research.

An ecological momentary assessment reviewing the link between emotional and sleep alterations in patients with insomnia was conducted. This study is a secondary analysis of data obtained to create a screening questionnaire for a sleep program for parents with sleep and settling difficulties.

Former studies showed that more investigation was needed to understand how insomnia disorder interacts with emotional processes. Insomnia is the most common sleep disorder, and theoretical models of insomnia have shown that patients experience more cognitive activity during the night, which is negatively expressed, and link feelings of discomfort and stress with nights of poor sleep.

First, physiological (heart rate and heart rate variability) and subjective (sleep and emotions) parameters were monitored for 5 days in patients with insomnia disorder (n = 97), good sleepers under self-imposed sleep restriction (n = 41), and good sleepers with usual amount of sleep (n = 45). Next, the researchers reviewed differences in emotion regulation strategies and in valence and variability of emotional experiences. Over 5 days, patients with insomnia displayed greater sleep and emotional difficulties compared with both control groups.

Separate from group allocation, days with more negative emotions were linked with higher sleep alternations. Longer wake episodes at night and higher diurnal heart rate were associated with greater variations in emotion experienced during the day. Only in patients with insomnia was use of adaptive emotion regulation strategies associated with higher sleep efficiency.

Indicators of maternal depression were measured using the Edinburgh Postnatal Depression Scale (EPDS-10), a 10-item self-report measure. In the study sample, 38.4% of mothers reported EPDS-10 scores of 9 or higher, which may suggest significant depressive symptoms.

Using a more limited cut-off score of 13 or higher to avoid false negatives, 17.6% of mothers likely meet the diagnostic criteria of major depressive disorder. In this study, 52.6% of mothers averaged less than 7 hours of sleep per night. In line with recommended interpretations of sleep problems, 18.8% of children had less than 9 hours of sleep, 22.4% woke more than 3 times per night, and 57.9% had a nocturnal waking duration of less than 1 hour. Aligned with the use of cut-off criteria, 66.0% of children in this study, regardless of age, had a sleep problem (minor, 31.2%; moderate, 24.1%; major, 10.7%).

“Our findings showed that having a child with a sleep problem alone does not predict depression, but the effects of a child's sleep problem on maternal sleep duration and self-efficacy indirectly predict depression,” said the researchers.

The current data showed that when sleep is disrupted, emotional responses are changed. Longer awakening times during the night are linked with increased variations in emotional experience and report of stronger negative emotions. Longer sleep onset latencies (SOLs) are also associated with stronger negative emotions.

Sleep deprivation is linked with lower ability in choosing adaptive strategies to monitor emotional responses when distressed. Lastly, chronic insomnia is linked with alternations in various emotional functioning areas: core valence and intensity of affect and abilities in regulating emotional responses. Alternatively, patients displayed a positive association between daily use of adaptive emotion regulation strategies and report of strong positive emotions with better sleep efficiency.

The researchers noted, “This may suggest a protective effect of positive emotions and adaptive emotion regulation strategies on body functions and sleep processes.”

To the researchers’ knowledge, the present study is the largest conducted to date to include longitudinal associations between sleep and emotional processes and use of physiological and subjective data.

This study comes with some limitations. First, even though the researchers’ ecological momentary assessment (EMA) data were prospective, their analysis could only provide information on daily associations. Second, EMA-reviewed emotional processes have greater ecological validity and decreased biased recall compared with self-report questionnaire; nonetheless, their data were still necessarily based on participants’ perceptions.

“We suggest that aspects of emotional experience should be assessed in a clinical context when treating insomnia. Improving skills in emotion regulation may improve treatment outcomes,” concluded the researchers.

Reference

Baglioni, C, Johann, A F, Benz, F, et al. (2023). Interactions between insomnia, sleep duration and emotional processes: an ecological momentary assessment of longitudinal influences combining self-report and physiological measures. J Sleep Res. Published Online July 25, 2023. doi:10.1111/jsr.14001