ArticlePsychological medicine2021
Fractal biomarker of activity in patients with bipolar disorder.
Article in Psychological medicine, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 papers, 1 of them a synthesis that pooled it.
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Who cites it
13 citing papers in PubMed, 1 synthesis or guideline pooled it, 16 citations in OpenAlex.
- Toward a Digital Future in Bipolar Disorder Assessment: A Systematic Review of Disruptions in the Rest-Activity Cycle as Measured by Actigraphy.Frontiers in psychiatry · 2022Pooled it
- Self images: an empirical enquiry into Rembrandt's self-portraits.Frontiers in psychiatry · 2026Article
- Fractal biomarker of daily activity for women with early onset depression.BMJ mental health · 2025Article
- Maximum and minimum activity in inpatient adolescents with Bipolar Disorders: Daily-Variability classification of actigraphy pattern with artificial intelligence.Psychiatry research communications · 2025Article
- Detecting the fractal physical activity pattern in aged adults with cerebral small vessel disease.Frontiers in aging neuroscience · 2025Article
- General spectral characteristics of human activity and its inherent scale-free fluctuations.Scientific reports · 2024Article
- Increased regional Hurst exponent reflects response inhibition related neural complexity alterations in pediatric bipolar disorder patients during an emotional Go-Nogo task.Cerebral cortex (New York, N.Y. : 1991) · 2024Article
- Advances in Understanding Fractals in Affective and Anxiety Disorders.Advances in neurobiology · 2024Review
- Altered Motor Activity Patterns within 10-Minute Timescale Predict Incident Clinical Alzheimer's Disease.Journal of Alzheimer's disease : JAD · 2024Article
- Automated analysis of activity, sleep, and rhythmic behaviour in various animal species with the Rtivity software.Scientific reports · 2022Article
- Complexity of Body Movements during Sleep in Children with Autism Spectrum Disorder.Entropy (Basel, Switzerland) · 2021Article
- An evidence map of actigraphy studies exploring longitudinal associations between rest-activity rhythms and course and outcome of bipolar disorders.International journal of bipolar disorders · 2020Review
- Classification of Actigraphy Records from Bipolar Disorder Patients Using Slope Entropy: A Feasibility Study.Entropy (Basel, Switzerland) · 2020Article
Corrections and comments
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Authors and funding
8 authors at 3 institutions in 2 countries.
Funding
Abstract
backgroundThe output of many healthy physiological systems displays fractal fluctuations with self-similar temporal structures. Altered fractal patterns are associated with pathological conditions. There is evidence that patients with bipolar disorder have altered daily behaviors.
methodsTo test whether fractal patterns in motor activity are altered in patients with bipolar disorder, we analyzed 2-week actigraphy data collected from 106 patients with bipolar disorder type I in a euthymic state, 73 unaffected siblings of patients, and 76 controls. To examine the link between fractal patterns and symptoms, we analyzed 180-day actigraphy and mood symptom data that were simultaneously collected from 14 patients.
resultsCompared to controls, patients showed excessive regularity in motor activity fluctuations at small time scales (<1.5 h) as quantified by a larger scaling exponent (α1 > 1), indicating a more rigid motor control system. α1 values of siblings were between those of patients and controls. Further examinations revealed that the group differences in α1 were only significant in females. Sex also affected the group differences in fractal patterns at larger time scales (>2 h) as quantified by scaling exponent α2. Specifically, female patients and siblings had a smaller α2 compared to female controls, indicating more random activity fluctuations; while male patients had a larger α2 compared to male controls. Interestingly, a higher weekly depression score was associated with a lower α1 in the subsequent week.
conclusionsOur results show sex- and scale-dependent alterations in fractal activity regulation in patients with bipolar disorder. The mechanisms underlying the alterations are yet to be determined.
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