Disturbed sleep as a clinical marker of wish to die: A smartphone monitoring study over three months of observation

Empirical clustering to identify individuals for whom insomnia is more closely related to suicidal ideation

BACKGROUND

Although the effect sizes are modest, insomnia is consistently associated with suicidal thoughts and behaviors. Subgroup analyses can efficiently identify for whom insomnia is most relevant to suicidal ideation. To improve clinical case identification, the present study sought to identify subclusters of lifetime suicidal ideators for whom insomnia was most closely related to current suicidal ideation.

METHODS

Data on N = 4750 lifetime suicidal ideators were extracted from the Military Suicide Research Consortium's Common Data Elements. Data on sociodemographic characteristics, severity and history of suicidal thoughts and behaviors, and related clinical characteristics were clustered by unsupervised machine learning algorithms. Robust Poisson regression estimated cluster by insomnia associations with current suicidal ideation.

RESULTS

Three clusters were identified: a modest symptom severity cluster (N = 1757, 37.0 %), an elevated severity cluster (N = 1444 30.4 %), and a high severity cluster (N = 1549 32.6 %). In Cluster 1, insomnia was associated with current suicidal ideation (PRR 1.29 [1.13-1.46]) and remained significant after adjusting for sociodemographic and clinical covariates. In Cluster 2, insomnia was associated with current suicidal ideation (PRR 1.14 [1.01-1.30]), but not after adjusting for sociodemographic and clinical covariates. In Cluster 3, insomnia was associated with current suicidal ideation (PRR 1.12 [1.03-1.21]) and remained significant after adjusting for sociodemographic covariates, but not clinical covariates.

LIMITATIONS

Cross-sectional design, lack of diagnostic data, non-representative sample.

CONCLUSION

Insomnia appears more closely related to current suicidal ideation among modest severity individuals than other subgroups. Future work should use prospective designs and more comprehensive risk factor measures to confirm these findings.

Association between sedentary behavior and wish to die among adults aged ≥50 years: Findings from the Irish Longitudinal Study on Ageing

We investigated the association between sedentary behavior (SB) and wish to die (WTD; i.e., feeling that one would be better off dead or wishing for one's own death), and the extent to which this can be explained by sleep problems, depression, anxiety, loneliness, perceived stress, and social network in a nationally representative sample of adults aged ≥50 years from Ireland. Cross-sectional data from Wave 1 of the Irish Longitudinal Study on Ageing 2009-2011 were analyzed. WTD was defined as answering affirmatively to the question "In the last month, have you felt that you would rather be dead?" SB was used as a continuous variable (hours/day), and also as a categorical (< or ≥8 h/day) variable. Multivariable logistic regression and mediation analyses were conducted. Data on 8163 adults aged ≥50 years were analyzed [mean (SD) age 63.6 (9.1) years; 48.0% males]. Overall, ≥8 (vs. <8) hours/day of SB was associated with a significant 2.04 (95%CI = 1.50-2.76) times higher odds for WTD, while a 1-h increase in SB per day was associated with 1.11 (95%CI = 1.06-1.16) times higher odds for WTD. Mediation analysis showed that sleep problems, depression, loneliness, perceived stress, and social network explained a modest proportion of the association between SB and WTD (mediated percentage 9.3%-14.8%). The present cross-sectional study found that increasing or higher levels of SB is positively associated with WTD. Addressing the identified potential mediators may reduce WTD among people who are sedentary. However, future longitudinal and intervention studies are needed to make concrete recommendations.

Multidimensional variability in ecological assessments predicts two clusters of suicidal patients

The variability of suicidal thoughts and other clinical factors during follow-up has emerged as a promising phenotype to identify vulnerable patients through Ecological Momentary Assessment (EMA). In this study, we aimed to (1) identify clusters of clinical variability, and (2) examine the features associated with high variability. We studied a set of 275 adult patients treated for a suicidal crisis in the outpatient and emergency psychiatric departments of five clinical centers across Spain and France. Data included a total of 48,489 answers to 32 EMA questions, as well as baseline and follow-up validated data from clinical assessments. A Gaussian Mixture Model (GMM) was used to cluster the patients according to EMA variability during follow-up along six clinical domains. We then used a random forest algorithm to identify the clinical features that can be used to predict the level of variability. The GMM confirmed that suicidal patients are best clustered in two groups with EMA data: low- and high-variability. The high-variability group showed more instability in all dimensions, particularly in social withdrawal, sleep measures, wish to live, and social support. Both clusters were separated by ten clinical features (AUC = 0.74), including depressive symptoms, cognitive instability, the intensity and frequency of passive suicidal ideation, and the occurrence of clinical events, such as suicide attempts or emergency visits during follow-up. Initiatives to follow up suicidal patients with ecological measures should take into account the existence of a high variability cluster, which could be identified before the follow-up begins.

The temporal dynamics of wish to live, wish to die, and their short-term prospective relationships with suicidal desire

The internal debate hypothesis (Kovacs & Beck, 1977) suggests that those at risk for suicidal thoughts and behaviors may experience fluctuations in both the wish to live (WTL) and wish to die (WTD). Previous research has investigated this hypothesis using various cross-sectional (Goods et al., 2019 [cf. Page & Stritzke, 2020]) and longitudinal methodologies (e.g., Bryan et al., 2016). No investigations have determined the within-day temporal dynamics of WTL and WTD using ecological moment assessment (EMA), however. N = 49 undergraduate university students recruited from a research participant pool from a large southeastern university in the United States with a lifetime history of suicide ideation completed the current 10-day EMA investigation. Results demonstrated that WTL, WTD, and resulting suicidal ambivalence (i.e., relatively equal WTL/WTD ratings) demonstrated similar within-person person variability; however, WTD scores appeared to demonstrate higher average variability compared to WTL and ambivalence scores. Although state WTL and WTD were concurrently related to state suicidal desire, only WTD prospectively predicted suicidal desire when controlling for the influence of the outcome variable at the previous timepoint. Ambivalence scores also prospectively predicted suicidal desire when controlling for suicidal desire at the previous timepoint. Results support the clinical and theoretical utility of separate WTL and WTD assessment. WTD was relatively stable within this sample but may be closely related to risk for future suicidal thinking. Changes in WTL may reduce state risk for suicidal desire but could be more trait-like in nature compared to WTD. Future research that investigates these hypotheses should consider the study limitations outlined.

Don't Miss the Moment: A Systematic Review of Ecological Momentary Assessment in Suicide Research

Suicide and suicide-related behaviors are prevalent yet notoriously difficult to predict. Specifically, short-term predictors and correlates of suicide risk remain largely unknown. Ecological momentary assessment (EMA) may be used to assess how suicidal thoughts and behaviors (STBs) unfold in real-world contexts. We conducted a systematic literature review of EMA studies in suicide research to assess (1) how EMA has been utilized in the study of STBs (i.e., methodology, findings), and (2) the feasibility, validity and safety of EMA in the study of STBs. We identified 45 articles, detailing 23 studies. Studies mainly focused on examining how known longitudinal predictors of suicidal ideation perform within shorter (hourly, daily) time frames. Recent studies have explored the prospects of digital phenotyping of individuals with suicidal ideation. The results indicate that suicidal ideation fluctuates substantially over time (hours, days), and that individuals with higher mean ideation also have more fluctuations. Higher suicidal ideation instability may represent a phenotypic indicator for increased suicide risk. Few studies succeeded in establishing prospective predictors of suicidal ideation beyond prior ideation itself. Some studies show negative affect, hopelessness and burdensomeness to predict increased ideation within-day, and sleep characteristics to impact next-day ideation. The feasibility of EMA is encouraging: agreement to participate in EMA research was moderate to high (median = 77%), and compliance rates similar to those in other clinical samples (median response rate = 70%). More individuals reported suicidal ideation through EMA than traditional (retrospective) self-report measures. Regarding safety, no evidence was found of systematic reactivity of mood or suicidal ideation to repeated assessments of STBs. In conclusion, suicidal ideation can fluctuate substantially over short periods of time, and EMA is a suitable method for capturing these fluctuations. Some specific predictors of subsequent ideation have been identified, but these findings warrant further replication. While repeated EMA assessments do not appear to result in systematic reactivity in STBs, participant burden and safety remains a consideration when studying high-risk populations. Considerations for designing and reporting on EMA studies in suicide research are discussed.

Differentiating the associations between sleep quality and suicide behaviors: A population-based study in China

BACKGROUND

Although the association between sleep problems and suicidal behaviors were found in many studies, their associations are not built until now. One of the reasons may be the identified differences among different suicide behaviors, which also implied that sleep quality may play different roles on these suicidal behaviors. However, absent study explores the possible distinguishing associations between sleep quality and different suicidal behaviors.

METHODS

This is a population-based study conducted in Hebei province, China. Totally, 21,376 valid questionnaires were analyzed in this study. Pittsburgh Sleep Quality Index (PSQI) was used to evaluate sleep quality. Suicidal behaviors, living alone, and social-demographic variables were assessed for all the participants.

RESULTS

The prevalence of suicidal ideation, plan, and attempt were 1.4%, 0.3%, and 0.2%, respectively. The PSQI scores were separately associated with suicidal ideation (OR=1.25, p<0.001), plan (OR=1.19, p<0.001), and attempt (OR=1.18, p<0.001). The similar results were also supported when we compared conditional suicidal behaviors with general population without any suicidal behaviors. However, when we compared suicide attempters with suicidal ideators (with or without suicide plan), the associations between PSQI scores and suicide attempt were not supported (OR=1.93, P>0.05 or OR=1.02, p>0.05).

LIMITATIONS

The cross-sectional design made us cannot get any causal relationships. The self-reported sleep quality may also produce some influence on the results.

CONCLUSION

The results imply us that improving sleep quality may be not effective to control further suicidal behaviors, when people have considered or planned to suicide. The findings also can be translated into the clinical and preventive practice for suicide control.