Inactograms and objective sleep measures as means to capture subjective sleep problems in patients with a bipolar disorder

Abstract

Background Sleep problems are common in bipolar disorders (BDs). To objectively characterize these problems in BDs, further methodological development is needed to capture subjective insomnia. Aim To test psychometric properties of the Athens Insomnia Scale (AIS), and associations with actigraphy‐derived measures, applying modifications in actigraphy data processing to capture features of perturbed sleep in patients with a BD. Methods Seventy‐four patients completed the AIS and the Quick Inventory of Depressive Symptomatology, self‐report (QIDS‐SR‐16). Locomotor activity was continuously recorded by wrist actigraphy for ≥10 consecutive days. We computed the sleep onset/offset, the center of daily inactivity (CenDI), as a proxy for chronotype, and the degree of consolidation of daily inactivity (ConDI), as a proxy for sleep‐wake rhythm strength. Results AIS showed good psychometric properties (Cronbach's alpha = 0.84; test–retest correlation = 0.84, P<.001). Subjective sleep problems correlated moderately with a later sleep phase (CenDI with AIS rho = 0.34, P = .003), lower consolidation (ConDI with AIS rho = −0.22, P = .05; with QIDS‐SR‐16 rho = −0.27, P = .019), later timing of sleep offset (with AIS rho = 0.49, P = ≤.001, with QIDS‐SR‐16 rho = 0.36, P = .002), and longer total sleep (with AIS rho = 0.29, P = .012, with QIDS‐SR‐16 rho = 0.41, P = ≤.001). While AIS was psychometrically more solid, correlations with objective sleep were more consistent across time for QIDS‐SR‐16. Conclusions AIS and QIDS‐SR‐16 are suitable for clinical screening of sleep problems among patients with a BD. Subjective insomnia associated with objective measures. For clinical and research purposes, actigraphy and data visualization on inactograms are useful for accurate longitudinal characterization of sleep patterns.

Suicidal Ideation and Insomnia in Bipolar Disorders: Idéation suicidaire et insomnie dans les troubles bipolaires

“…We addressed this using recent open-source algorithms, which are device independent, have been validated against polysomnography, and we added use of a moving time window as described in detail previously. 26 Late sleep offset was found to associate with lifetime suicidality in our sample, consistent with results from a large Korean study. 32 This finding necessitates further work given the small number of patients with SAs in our data.…”

“…Our markers were selected based on the validation of actigraphy data with patient-reported sleep onset/offset and our preference to focus on inactivity rather than activity to mitigate confounders. However, to facilitate reproducibility, we have published algorithms for inactograms 26 and used open-source algorithms for the dimensional measures.…”

“…Upon entry into the study (V1), all participants were outfitted with GENEActiv actigraphy devices (ActivInsights) for measurement of (in)activity and were instructed to wear the devices continuously for 2 weeks. Sleep variables were produced from actigraphy data (for detailed methods and validation see references [26][27][28] ). Briefly, Center of daily inactivity (CenDI) describes the mean direction of inactivity, measured as the daily distribution of sleep in radian angle of the sleep vector.…”

“…We also calculated onset, offset, and total duration of sleep as described previously. 26,27 The standard deviations (SDs) of the aforementioned variables were also calculated to describe the degree of their day-to-day variation.…”

Actigraphic patterns, impulsivity, and mood instability in bipolar disorder, borderline personality disorder, and healthy controls

“…What worries us is that the sleep–wake cycle results of the BD group were comparable to that of healthy controls. This contrasts robust data from this population (2). Additionally, correlations performed between sleep variables, impulsivity, and mood were not statistically significant for the BD group.…”