Actigraphy and polysomnography (PSG) are two prominent methods for measuring sleep patterns, particularly in patients with bipolar disorder. Each method has its strengths and limitations, making them suitable for different contexts in sleep research and clinical practice. In this article, we are going to explain why Mindpax Miu.me relies on actigraphy data, rather than polysomnography.
Bipolar disorder is highly influenced by sleep patterns, as disruptions in circadian rhythms can trigger mood episodes. Sleep deprivation often precedes manic episodes, while excessive sleep can accompany depressive phases, indicating a direct relationship between sleep and mood regulation in these individuals. The Rest-Activity Regime (RAR) serves as an objective marker for monitoring this connection, as it quantifies activity levels and rest periods over time using wearable or digital devices. By capturing fluctuations in daily patterns, RAR provides insights into circadian stability or disturbances, helping clinicians detect early signs of mood shifts and tailor interventions to stabilize sleep-wake cycles, thereby improving symptom management.
Comparison of methods to track sleep patterns and quality
– Polysomnography (PSG): PSG is considered the “gold standard” for sleep measurement. It involves comprehensive monitoring of physiological functions during sleep, including brain activity (EEG), eye movements (EOG), and muscle activity (EMG). This method is typically conducted in a sleep laboratory, which can be costly and burdensome for patients due to the need for overnight stays and the complexity of the setup.
– Actigraphy: Actigraphy uses a wrist-worn device that records movement over extended periods, providing a continuous record of activity levels. This method is less invasive and allows for naturalistic monitoring in the patient’s home environment. Actigraphy primarily infers sleep based on periods of inactivity, making it more convenient for long-term studies.
Does actigraphy miss relevant sleep information for tracking BAP compared to PSG? Nope!
Research shows that actigraphy produces results comparable to those obtained from PSG. A study comparing both methods found high concordance (up to 90%) in estimating key sleep parameters such as total sleep time, sleep efficiency, and wake after sleep onset [1][2].
Actigraphy tends to yield lower estimates of sleep latency compared to PSG. This discrepancy may arise because actigraphy cannot detect all physiological aspects of sleep that PSG measures[4]. Additionally, while actigraphy is effective in assessing general sleep patterns, it may misclassify periods of low activity as sleep if the device is not worn properly or if the patient is inactive but awake.
Advantages of actigraphic wearable devices
Actigraphy offers several advantages over polysomnography (PSG) for measuring sleep patterns in patients with bipolar disorder. Here are the main benefits:
- Non-Invasiveness and Comfort: Actigraphy utilizes a small wrist-worn device that records movement, allowing patients to monitor their sleep patterns in a natural environment without the discomfort of multiple sensors attached to their bodies, as required in PSG [1][2].
- Continuous Monitoring: Patients can wear the actigraph continuously for extended periods (months or even years), facilitating long-term monitoring of sleep and activity patterns without the need for overnight stays in a lab [1][2].
- Lower Costs: Actigraphy is generally more affordable than PSG, which requires specialized equipment and trained personnel for conducting sleep studies in a clinical setting. This makes actigraphy more accessible for regular monitoring and research purposes [1][2].
- Real-World Data: Actigraphy captures sleep data in the patient’s everyday environment, providing insights into how daily life and external factors influence sleep patterns. This ecological validity is particularly important for understanding the context of mood fluctuations in bipolar disorder [1][2].
- Reduced Burden on Patients: Unlike PSG, which requires scheduled visits to a sleep clinic, actigraphy allows patients to collect data passively without disrupting their daily routines. This reduces the burden associated with sleep assessments, making it easier for patients to comply with monitoring [1][2].
- Identification of Patterns and Trends: Actigraphs can analyze and visualize trends in sleep and activity levels over time, enabling both patients and healthcare providers to identify changes that may signal mood episodes or other significant developments in the patient’s condition [2][3].
In summary, actigraphy presents a practical, cost-effective, and patient-friendly alternative to polysomnography for monitoring sleep patterns in individuals with bipolar disorder. Its ability to provide continuous, real-world data while maintaining high validity makes it an essential tool for both clinical practice and research in understanding the relationship between sleep disturbances and mood regulation in this population.
Sources
[1] Kaplan, K. A., Talbot, L. S., Gruber, J., & Harvey, A. G. (2012). Evaluating sleep in bipolar disorder: comparison between actigraphy, polysomnography, and sleep diary. Bipolar Disorders, 14(8), 870–879. https://doi.org/10.1111/bdi.12021
[2] Actigraphy In Psychiatry – Mindpax https://mindpax.me/en/actigraphy-in-psychiatry/
[3] Smith, M. T., McCrae, C. S., Cheung, J., Martin, J. L., Harrod, C. G., Heald, J. L., & Carden, K. A. (2018). Use of Actigraphy for the Evaluation of Sleep Disorders and Circadian Rhythm Sleep-Wake Disorders: An American Academy of Sleep Medicine Systematic Review, Meta-Analysis, and GRADE Assessment. Journal of Clinical Sleep Medicine, 14(07), 1209–1230. https://doi.org/10.5664/jcsm.7228
[4] Lehrer, H. M., Yao, Z., Krafty, R. T., Evans, M. A., Buysse, D. J., Kravitz, H. M., Matthews, K. A., Gold, E. B., Harlow, S. D., Samuelsson, L. B., & Hall, M. H. (2022). Comparing polysomnography, actigraphy, and sleep diary in the home environment: The Study of Women’s Health Across the Nation (SWAN) Sleep Study. SLEEP Advances, 3(1). https://doi.org/10.1093/sleepadvances/zpac001
