Sleep-Related Attentional Bias in Insomnia: Time to Examine Moderating Factors?

Daytime sleepiness in insomnia: Are we focusing on what truly matters?

Insomnia, the most prevalent sleep disorder, is commonly associated with other mental and somatic disorders, making it a significant health concern. It is characterized by nighttime symptoms and daytime dysfunction, with sleepiness being a potential criterion for the latter. Sleepiness is a normal physiological state that is typically experienced near usual bedtime, in normal circumstances. In insomnia, it seems somewhat logical the idea that there is significant daytime sleepiness. However, the topic has been the subject of various discussions in sleep medicine, with studies yielding contradictory and inconsistent results. In this article, we aim to critically examine daytime sleepiness in individuals with insomnia disorder and propose an alternative approach to addressing it, both in clinical practice and research settings. It is crucial to further investigate the role of daytime sleepiness in insomnia, particularly by focusing on sleepiness perception as a more relevant dimension to explore in majority of patients. It is plausible that certain insomnia phenotypes are objectively sleepy during the day, but more studies are necessary, particularly with well-defined clinical samples. The implications of assessing sleepiness perception in insomnia for clinical practice are discussed, and new avenues for research are suggested.

Sleep-related attentional bias in insomnia: The mediating role of arousal

BACKGROUND AND OBJECTIVES

Characterize the nature of attentional biases toward nocturnal and diurnal sleep-related stimuli in individuals with insomnia disorder. We investigated the contributing role of sleep-related attentional biases in insomnia severity and whether their effects on insomnia severity were mediated by arousal and valence levels of the presented stimuli.

METHODS

Sixty-four individuals with insomnia disorder and 70 controls completed two Posner spatial cueing tasks including both nocturnal (alarm clocks) and diurnal (fatigue) pictorial stimuli associated with neutral cues. Arousal and valence of the sleep-related stimuli were assessed using a 5-point Likert type scale.

RESULTS

Attention biases characterized by difficulty disengaging from and increased avoidance for daytime fatigue, and by difficulty disengaging from alarm clocks were observed in individuals with insomnia disorder compared to controls. On the whole sample, difficulty to disengage from diurnal and nocturnal sleep-related stimuli were related mostly to higher arousal rating of sleep-related stimuli and insomnia severity. Higher arousal rating for sleep-related stimuli mediates the relationship between difficulty disengaging and insomnia severity.

LIMITATIONS

The cross-sectional nature of the study.

CONCLUSIONS

We provide first initial evidence for an attentional bias characterized by on one side, avoidance for diurnal sleep-related stimuli and on other side, disengagement for both diurnal and nocturnal sleep-related stimuli in patients with insomnia. Disengagement difficulties for both diurnal and nocturnal sleep-related stimuli indirectly affected insomnia severity through arousal elicited by these stimuli. It appears important to develop and apply attentional bias modification training therapeutic interventions that can effectively reduce sleep-related arousal and attentional biases.

Evaluating the Modified Patient Health Questionnaire-2 and Insomnia Severity Index-2 for Daily Digital Screening of Depression and Insomnia: Validation Study

BACKGROUND

The Patient Health Questionnaire-2 (PHQ-2) and Insomnia Severity Index-2 (ISI-2) are screening assessments that reflect the past 2-week experience of depression and insomnia, respectively. Retrospective assessment has been associated with reduced accuracy owing to recall bias.

OBJECTIVE

This study aimed to increase the reliability of responses by validating the use of the PHQ-2 and ISI-2 for daily screening.

METHODS

A total of 167 outpatients from the psychiatric department at the Yongin Severance Hospital participated in this study, of which 63 (37.7%) were male and 104 (62.3%) were female with a mean age of 35.1 (SD 12.1) years. Participants used a mobile app ("Mental Protector") for 4 weeks and rated their depressive and insomnia symptoms daily on the modified PHQ-2 and ISI-2 scales. The validation assessments were conducted in 2 blocks, each with a fortnight response from the participants. The modified version of the PHQ-2 was evaluated against the conventional scales of the Patient Health Questionnaire-9 and the Korean version of the Center for Epidemiologic Studies Depression Scale-Revised.

RESULTS

According to the sensitivity and specificity analyses, an average score of 3.29 on the modified PHQ-2 was considered valid for screening for depressive symptoms. Similarly, the ISI-2 was evaluated against the conventional scale, Insomnia Severity Index, and a mean score of 3.50 was determined to be a valid threshold for insomnia symptoms when rated daily.

CONCLUSIONS

This study is one of the first to propose a daily digital screening measure for depression and insomnia delivered through a mobile app. The modified PHQ-2 and ISI-2 were strong candidates for daily screening of depression and insomnia, respectively.

Sleep-related attentional and interpretive-bias in insomnia: A systematic review and meta-analysis

Cognitive models of insomnia highlight internal and external cognitive-biases for sleep-related "threat" in maintaining the disorder. This systematic review of the sleep-related attentional and interpretive-bias literature includes meta-analytic calculations of each construct. Searches identified N = 21 attentional-bias and N = 8 interpretive-bias studies meeting the inclusion/exclusion criteria. Seventeen attentional-bias studies compared normal-sleepers and poor-sleepers/insomnia patients. Using a random effects model, meta-analytic data based on standardized mean differences of attentional-bias studies determined the weighted pooled effect size to be moderate at 0.60 (95%CI:0.26-0.93). Likewise, seven of eight interpretive-bias studies involved group comparisons. Meta-analytic data determined the weighted pooled effect size as moderate at .44 (95%CI:0.19-0.69). Considering these outcomes, disorder congruent cognitive-biases appear to be a key feature of insomnia. Despite statistical support, absence of longitudinal data limits causal inference concerning the relative role cognitive-biases in the development and maintenance of insomnia. Methodological factors pertaining to task design, sample and stimuli are discussed in relation to outcome variation. Finally, we discuss the next steps in advancing the understanding of sleep-related biases in insomnia.

Strange themes in pandemic dreams: Insomnia was associated with more negative, anxious and death-related dreams during the COVID-19 pandemic

Dreaming and insomnia are important markers of distress in times of crisis. Here, we present a longitudinal, mixed-methods study examining changes in dreaming between individuals with and without insomnia symptoms and their relationship to mental health during the COVID-19 pandemic. A global survey examining insomnia symptoms, dreams and mental health was launched in April 2020 and followed participants over 12 months. Of 2240 participants, 1009 (45%) reported dream changes at baseline. A higher proportion of participants with new-onset insomnia reported dream changes (55%) than those with pre-existing insomnia (45%) or good sleepers (36%). Overall, thematic analysis identified key dream change themes of increased dream activity, with participants dreaming vividly, in high-definition, and with a strong negative charge. Themes around survival, adjusting to pandemic life, meaning-making and poor sleep quality were also noted. Linguistic Inquiry Word Count showed that individuals with insomnia used more negative words to describe their dream changes than good sleepers. Specifically, the new-onset insomnia group used more anxious and death-related words than those who slept well. Notably, all groups experienced a significant reduction in dream activity by 3-month follow-up. Lastly, dream changes were associated with worse mental health symptoms over time, and this effect was more pronounced in individuals with insomnia. Our results highlight that insomnia symptoms, especially new-onset insomnia, are associated with more negative dream changes during collective stressful events, potentially compounding daytime distress and mental health symptoms over time. During times of crisis, dreaming and insomnia may reveal an important target for mental health interventions.

Sleep-related monitoring on awakening mediates the relationship between insomnia-related interpretive bias and insomnia symptoms using the insomnia ambiguity paradigm

A number of studies have examined and confirmed the presence of a sleep-related interpretive bias amongst poor sleepers and individuals with insomnia using an insomnia ambiguity task. This study explored possible mechanisms underlying the relationship between interpretive bias and insomnia using the insomnia ambiguity task. More importantly, the possible mediating role of sleep-associated monitoring, sleep preoccupation, sleep anticipatory anxiety and generalized anxiety was also examined. A total of N = 176 participants were stratified into normal sleepers and those displaying insomnia symptoms. Participants completed an online version of the insomnia ambiguity task and questionnaire measures pertaining to sleep and anxiety. Data concerning task response time and time of testing were also collected. Individuals in the insomnia symptom group presented significantly higher sleep-related interpretive bias scores compared to normal sleepers. When sleepiness, sleep-associated monitoring, sleep preoccupation, sleep anticipatory anxiety and generalized anxiety were controlled for, only monitoring on awakening predicted sleep-related interpretive bias. Multiple mediation modelling demonstrated that sleep-associated monitoring on awakening mediated the relationship between interpretive bias and insomnia symptoms. The current outcomes are consistent with previous research, supporting the notion that insomnia is characterized by a disorder-consistent interpretive bias. Furthermore, monitoring for insomnia-consistent cues on awakening appears to mediate group differences in interpretive bias.