Chronotypes and circadian rest–activity rhythms in bipolar disorders: a meta‐analysis of self‐ and observer rating scales

Abstract

Objective Chronobiological models postulate that abnormalities in circadian rest/activity rhythms (CRAR) are core phenomena of bipolar disorders (BDs). We undertook a meta‐analysis of published studies to determine whether self‐ or observer ratings of CRAR differentiate BD cases from comparators (typically healthy controls [HCs]). Method We undertook systematic searches of four databases to identify studies for inclusion in random effects meta‐analyses and meta‐regression analyses. Effect sizes (ES) for pooled analyses of self‐ and observer ratings were expressed as standardized mean differences with 95% confidence intervals (CIs). Results The 30 studies meeting eligibility criteria included 2840 cases and 3573 controls. Compared with HC, BD cases showed greater eveningness (ES: 0.33; 95% CI: 0.12–0.54), lower flexibility of rhythms (ES: 0.36; 95% CI: 0.06–0.67), lower amplitude of rhythms (ES: 0.55; 95% CI: 0.39–0.70) and more disturbances across a range of CRAR (ES of 0.78–1.12 for general and social activities, sleep and eating patterns). Between study heterogeneity was high (I2 > 70%) and evidence indicated a potential publication bias for studies using the Biological Rhythms Interview of Assessment in Neuropsychiatry. Meta‐regression analyses suggested significantly larger ES were observed in studies using observer ratings or including BD cases with higher levels of depressive symptoms. Conclusion This meta‐analysis demonstrates that BD is associated with higher levels of self‐ or observer‐rated CRAR disturbances compared with controls. However, further studies should examine the respective performance of individual instruments when used alone or in combination, to clarify their applicability and utility in clinical practice.

Which Actigraphy Dimensions Predict Longitudinal Outcomes in Bipolar Disorders?

“…Other large-scale community cohort studies demonstrated associations between the amplitude and stability of circadian rhythms in BD [34]. Furthermore, systematic reviews and metaanalyses of cross-sectional studies of individuals with BD compared with healthy controls repeatedly suggest that circadian dysrhythmias are more common in patients, even in euthymia [16,35]. Nevertheless, there is still some debate about the state or trait nature of these abnormalities.…”

“…Second, chronobiological models offer a plausible explanation of the observed phenomenology of BD [15]. Third, several self-and observer-rated tools can be used to evaluate sleep quality, chronotypes or other aspects of sleep-wake patterns in clinical settings [13,16]. Fourth, studies have shown that these self-or observer-rated sleep disturbances assessed during inter-episode periods are associated with BD relapse or recurrence [17][18][19][20][21].…”

International e-Delphi Consensus Recommendations for the Assessment and Diagnosis of Circadian rest–Activity Rhythm Disorders (CARDs) in Patients with Cancer

“…Although the e-Delphi focused on RARs in patients with cancer, the recommendations highlight that disordered RARs can also occur in other clinical conditions. These include patients with neurodegenerative conditions (e.g., Parkinson's disease and Alzheimer's disease), psychiatric disorders (e.g., bipolar disorder), and respiratory disease (e.g., chronic obstructive pulmonary disease) [23][24][25][26]. Currently, evidence is insufficient Several factors highlighted in the recommendations modify circadian RARs to varying extents and should be considered during an assessment.…”

Bipolar Disorder, Circadian Rhythm and Clock Genes

“…Several studies analyzing circadian preferences of patients with bipolar disorder confirmed that patients with bipolar disorder prefer the evening type [ 51 - 54 ]. In a longitudinal follow-up study of patients with bipolar disorder, the evening type was associated with sleep disturbance regardless of mood episodes.…”