Disturbances in sleep and affect are prominent features of bipolar disorder, even during interepisode periods. Few longitudinal studies have prospectively examined the relationship between naturally occurring sleep and affect, and no studies to date have done so during interepisode periods of bipolar disorder and using the entire set of "gold standard" sleep parameters. Participants diagnosed with bipolar I disorder who were interepisode (n = 32) and healthy controls (n = 36) completed diagnostic and symptom severity interviews, and a daily sleep and affect diary, as well as an actigraphy sleep assessment, for eight weeks (M = 54 days, ± 8 days). Mutual information analysis was used to assess the degree of statistical dependence, or coupling, between time series data of sleep and affect. As measured by actigraphy, longer sleep onset latency was coupled with higher negative affect more strongly in the bipolar group than in the control group. As measured by sleep diary, longer wakefulness after sleep onset and lower sleep efficiency were coupled with higher negative affect significantly more strongly in the bipolar group than in the control group. By contrast, there were no significant differences between groups in the degree of coupling between any measures of sleep and positive affect. Findings support the coupling of sleep disturbance and negative affect during interepisode bipolar disorder. Ongoing monitoring of sleep-affect coupling may provide an important target for intervention in bipolar disorder. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
[Show abstract][Hide abstract] ABSTRACT: Objective:
Sleep dysregulation is highly prevalent in bipolar disorders (BDs), with previous actigraphic studies demonstrating sleep abnormalities during depressive, manic, and interepisode periods. We undertook a meta-analysis of published actigraphy studies to identify whether any abnormalities in the reported sleep profiles of remitted BD cases differ from controls.
A systematic review identified independent studies that were eligible for inclusion in a random effects meta-analysis. Effect sizes for actigraphy parameters were expressed as standardized mean differences (SMD) with 95% confidence intervals (95% CI).
Nine of 248 identified studies met eligibility criteria. Compared with controls (N=210), remitted BD cases (N=202) showed significant differences in SMD for sleep latency (0.51 [0.28-0.73]), sleep duration (0.57 [0.30-0.84]), wake after sleep onset (WASO) (0.28 [0.06-0.50]) and sleep efficiency (-0.38 [-0.70-0.07]). Moderate heterogeneity was identified for sleep duration (I2=44%) and sleep efficiency (I2=44%). Post hoc meta-regression analyses demonstrated that larger SMD for sleep duration were identified for studies with a greater age difference between BD cases and controls (β=0.22; P=0.03) and non-significantly lower levels of residual depressive symptoms in BD cases (β=-0.13; P=0.07).
This meta-analysis of sleep in remitted bipolar disorder highlights disturbances in several sleep parameters. Future actigraphy studies should pay attention to age matching and levels of residual depressive symptoms.
[Show abstract][Hide abstract] ABSTRACT: Over the past decade, researchers have shifted focus from the manic and depressive episodes to the interepisode period in the study of sleep-wake disturbance in bipolar disorder. The objective of this systematic review was to compile and synthesize studies that employed sleep diary, actigraphy, polysomnography, and questionnaires to compare sleep-wake patterns in people with interepisode bipolar disorder or high-risk individuals vs. normal controls and/or people with primary insomnia. We searched key databases until June 2013. Our search identified 21 eligible studies, yielding 24 sleep-wake variables. A total of 531 people with interepisode bipolar disorder, 157 high-risk individuals, 678 normal controls and 67 adults with primary insomnia were evaluated. Using a random-effects model, our analyses suggest that adults with interepisode bipolar disorder appear worse than normal controls in most variables and comparable to adults with primary insomnia in certain aspects. Sleep onset latency, wake after sleep onset, and variability of sleep-wake variables were most consistently impaired in interepisode bipolar disorder. In comparison with controls, high-risk individuals were found to have higher variability in sleep efficiency and lower relative amplitude. The findings provide a foundation for the search for candidate endophenotypes and the development of novel interventions for bipolar disorder.
Sleep Medicine Reviews 06/2014; 20. DOI:10.1016/j.smrv.2014.06.006 · 8.51 Impact Factor
" sleep and circadian rhythms in patients with bipolar disorder ( Geddes and Miklowitz , 2013 ) . Therefore , we believe that it is unlikely that psychotropic drugs had a major influence . Our sample size is small ; however , it is of reasonable size for an actigraphic study and larger than the median for the previous studies cited ( median ¼40 ) ( Gershon et al . , 2012 ; Harvey et al . , 2005 ; Jones et al . , 2005 ; Kaplan et al . , 2012 ; Millar et al . , 2004 ; Mullin et al . , 2011 ; Ritter et al . , 2012 ; Salvatore et al . , 2008 ; St - Amand et al . , 2012 ) . We studied several markers of subjective and objective sleep . Although GLM is an appropriate method for assessing multiple , potentiall"
[Show abstract][Hide abstract] ABSTRACT: Introduction
Findings from actigraphic studies suggesting that sleep and circadian rhythms are disrupted in bipolar disorder (BD) patients have been undermined by methodological heterogeneity and the failure to adequately address potential confounders.
Twenty-six euthymic BD cases and 29 healthy controls (HC), recruited from University Paris-Est and matched for age and gender, were compared on subjective (Pittsburgh Sleep Questionnaire Inventory; PQSI) and objective (mean scores and variability in actigraphy) measures of sleep as recorded by over 21 consecutive days.
Multivariate generalized linear modelling (GLM) revealed significant differences between BD cases and HC for five PSQI items (total score and four subscales), four actigraphy variables (mean scores) and five actigraphy variability measures. Backward stepwise linear regression (BSLR) indicated that a combination of four variables (mean sleep duration, mean sleep latency, variability of the fragmentation index over 21 days, and mean score on PSQI daytime dysfunction sub-scale) correctly classified 89% of study participants as cases or controls (Chi-square=39.81; df=6; p=0.001).
The sample size (although larger than most actigraphy studies) and incomplete matching of cases and controls may have influenced our findings. It was not possible to control for potential effects of psychotropic medication or differences in employment status between groups.
When potential confounders of sleep and circadian profiles are adequately taken into account (particularly age, gender, daytime sleepiness, mood symptoms, body mass index, and risk of sleep apnoea), a selected subset of quantitative (mean scores) and qualitative (variability) features differentiated euthymic BD cases from HC.
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