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| 2. |
- Bauer, M., et al.
(författare)
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Association between polarity of first episode and solar insolation in bipolar I disorder
- 2022
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Ingår i: Journal of Psychosomatic Research. - : Elsevier BV. - 0022-3999 .- 1879-1360. ; 160
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Circadian rhythm disruption is commonly observed in bipolar disorder (BD). Daylight is the most powerful signal to entrain the human circadian clock system. This exploratory study investigated if solar insolation at the onset location was associated with the polarity of the first episode of BD I. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area of the Earth. Methods: Data from 7488 patients with BD I were collected at 75 sites in 42 countries. The first episode occurred at 591 onset locations in 67 countries at a wide range of latitudes in both hemispheres. Solar insolation values were obtained for every onset location, and the ratio of the minimum mean monthly insolation to the maximum mean monthly insolation was calculated. This ratio is largest near the equator (with little change in solar insolation over the year), and smallest near the poles (where winter insolation is very small compared to summer insolation). This ratio also applies to tropical locations which may have a cloudy wet and clear dry season, rather than winter and summer. Results: The larger the change in solar insolation throughout the year (smaller the ratio between the minimum monthly and maximum monthly values), the greater the likelihood the first episode polarity was depression. Other associated variables were being female and increasing percentage of gross domestic product spent on country health expenditures. (All coefficients: P ≤ 0.001). Conclusion: Increased awareness and research into circadian dysfunction throughout the course of BD is warranted.
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| 3. |
- Bauer, M., et al.
(författare)
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Exploratory study of ultraviolet B (UVB) radiation and age of onset of bipolar disorder
- 2023
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Ingår i: International Journal of Bipolar Disorders. - 2194-7511. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundSunlight contains ultraviolet B (UVB) radiation that triggers the production of vitamin D by skin. Vitamin D has widespread effects on brain function in both developing and adult brains. However, many people live at latitudes (about > 40 N or S) that do not receive enough UVB in winter to produce vitamin D. This exploratory study investigated the association between the age of onset of bipolar I disorder and the threshold for UVB sufficient for vitamin D production in a large global sample.MethodsData for 6972 patients with bipolar I disorder were obtained at 75 collection sites in 41 countries in both hemispheres. The best model to assess the relation between the threshold for UVB sufficient for vitamin D production and age of onset included 1 or more months below the threshold, family history of mood disorders, and birth cohort. All coefficients estimated at P <= 0.001.ResultsThe 6972 patients had an onset in 582 locations in 70 countries, with a mean age of onset of 25.6 years. Of the onset locations, 34.0% had at least 1 month below the threshold for UVB sufficient for vitamin D production. The age of onset at locations with 1 or more months of less than or equal to the threshold for UVB was 1.66 years younger.ConclusionUVB and vitamin D may have an important influence on the development of bipolar disorder. Study limitations included a lack of data on patient vitamin D levels, lifestyles, or supplement use. More study of the impacts of UVB and vitamin D in bipolar disorder is needed to evaluate this supposition.
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| 4. |
- Bauer, M., et al.
(författare)
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Variations in seasonal solar insolation are associated with a history of suicide attempts in bipolar I disorder
- 2021
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Ingår i: International Journal of Bipolar Disorders. - : Springer Science and Business Media LLC. - 2194-7511. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Bipolar disorder is associated with circadian disruption and a high risk of suicidal behavior. In a previous exploratory study of patients with bipolar I disorder, we found that a history of suicide attempts was associated with differences between winter and summer levels of solar insolation. The purpose of this study was to confirm this finding using international data from 42% more collection sites and 25% more countries. Methods Data analyzed were from 71 prior and new collection sites in 40 countries at a wide range of latitudes. The analysis included 4876 patients with bipolar I disorder, 45% more data than previously analyzed. Of the patients, 1496 (30.7%) had a history of suicide attempt. Solar insolation data, the amount of the sun's electromagnetic energy striking the surface of the earth, was obtained for each onset location (479 locations in 64 countries). Results This analysis confirmed the results of the exploratory study with the same best model and slightly better statistical significance. There was a significant inverse association between a history of suicide attempts and the ratio of mean winter insolation to mean summer insolation (mean winter insolation/mean summer insolation). This ratio is largest near the equator which has little change in solar insolation over the year, and smallest near the poles where the winter insolation is very small compared to the summer insolation. Other variables in the model associated with an increased risk of suicide attempts were a history of alcohol or substance abuse, female gender, and younger birth cohort. The winter/summer insolation ratio was also replaced with the ratio of minimum mean monthly insolation to the maximum mean monthly insolation to accommodate insolation patterns in the tropics, and nearly identical results were found. All estimated coefficients were significant at p < 0.01. Conclusion A large change in solar insolation, both between winter and summer and between the minimum and maximum monthly values, may increase the risk of suicide attempts in bipolar I disorder. With frequent circadian rhythm dysfunction and suicidal behavior in bipolar disorder, greater understanding of the optimal roles of daylight and electric lighting in circadian entrainment is needed.
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| 5. |
- Bauer, M., et al.
(författare)
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Solar insolation in springtime influences age of onset of bipolar I disorder
- 2017
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Ingår i: Acta Psychiatrica Scandinavica. - : Wiley. - 0001-690X .- 1600-0447. ; 136:6, s. 571-582
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Forskningsöversikt (refereegranskat)abstract
- Objective: To confirm prior findings that the larger the maximum monthly increase in solar insolation in springtime, the younger the age of onset of bipolar disorder. Method: Data were collected from 5536 patients at 50 sites in 32 countries on six continents. Onset occurred at 456 locations in 57 countries. Variables included solar insolation, birth-cohort, family history, polarity of first episode and country physician density. Results: There was a significant, inverse association between the maximum monthly increase in solar insolation at the onset location, and the age of onset. This effect was reduced in those without a family history of mood disorders and with a first episode of mania rather than depression. The maximum monthly increase occurred in springtime. The youngest birth-cohort had the youngest age of onset. All prior relationships were confirmed using both the entire sample, and only the youngest birth-cohort (all estimated coefficients P < 0.001). Conclusion: A large increase in springtime solar insolation may impact the onset of bipolar disorder, especially with a family history of mood disorders. Recent societal changes that affect light exposure (LED lighting, mobile devices backlit with LEDs) may influence adaptability to a springtime circadian challenge.
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| 7. |
- Bauer, Michael, et al.
(författare)
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Association between solar insolation and a history of suicide attempts in bipolar I disorder.
- 2019
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Ingår i: Journal of psychiatric research. - : Elsevier BV. - 1879-1379 .- 0022-3956. ; 113, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- In many international studies, rates of completed suicide and suicide attempts have a seasonal pattern that peaks in spring or summer. This exploratory study investigated the association between solar insolation and a history of suicide attempt in patients with bipolar I disorder. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area on Earth. Data were collected previously from 5536 patients with bipolar I disorder at 50 collection sites in 32 countries at a wide range of latitudes in both hemispheres. Suicide related data were available for 3365 patients from 310 onset locations in 51 countries. 1047 (31.1%) had a history of suicide attempt. There was a significant inverse association between a history of suicide attempt and the ratio of mean winter solar insolation/mean summer solar insolation. This ratio is smallest near the poles where the winter insolation is very small compared to the summer insolation. This ratio is largest near the equator where there is relatively little variation in the insolation over the year. Other variables in the model that were positively associated with suicide attempt were being female, a history of alcohol or substance abuse, and being in a younger birth cohort. Living in a country with a state-sponsored religion decreased the association. (All estimated coefficients p<0.01). In summary, living in locations with large changes in solar insolation between winter and summer may be associated with increased suicide attempts in patients with bipolar disorder. Further investigation of the impacts of solar insolation on the course of bipolar disorder is needed.
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| 11. |
- Omrani, Mohsen, et al.
(författare)
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Perturbation-evoked responses in primary motor cortex are modulated by behavioral context
- 2014
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Ingår i: Journal of Neurophysiology. - : American Physiological Society. - 0022-3077 .- 1522-1598. ; 112:11, s. 2985-3000
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Tidskriftsartikel (refereegranskat)abstract
- Corrective responses to external perturbations are sensitive to the behavioral task being performed. It is believed that primary motor cortex (M1) forms part of a transcortical pathway that contributes to this sensitivity. Previous work has identified two distinct phases in the perturbation response of M1 neurons, an initial response starting similar to 20 ms after perturbation onset that does not depend on the intended motor action and a task- dependent response that begins similar to 40 ms after perturbation onset. However, this invariant initial response may reflect ongoing postural control or a task- independent response to the perturbation. The present study tested these two possibilities by examining if being engaged in an ongoing postural task before perturbation onset modulated the initial perturbation response in M1. Specifically, mechanical perturbations were applied to the shoulder and/ or elbow while the monkey maintained its hand at a central target or when it was watching a movie and not required to respond to the perturbation. As expected, corrective movements, muscle stretch responses, and M1 population activity in the late perturbation epoch were all significantly diminished in the movie task. Strikingly, initial perturbation responses (<40 ms postperturbation) remained the same across tasks, suggesting that the initial phase of M1 activity constitutes a task- independent response that is sensitive to the properties of the mechanical perturbation but not the goal of the ongoing motor task.
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| 12. |
- Qin, Rennie X., et al.
(författare)
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Building sustainable and resilient surgical systems : A narrative review of opportunities to integrate climate change into national surgical planning in the Western Pacific region
- 2022
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Ingår i: The Lancet Regional Health. Western Pacific. - : The Lancet Publishing Group ; Elsevier. - 2666-6065. ; 22
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Forskningsöversikt (refereegranskat)abstract
- Five billion people lack access to surgical care worldwide; climate change is the biggest threat to human health in the 21st century. This review studies how climate change could be integrated into national surgical planning in the Western Pacific region. We searched databases (PubMed, Web of Science, and Global Health) for articles on climate change and surgical care. Findings were categorised using the modified World Health Organisation Health System Building Blocks Framework. 220 out of 2577 records were included. Infrastructure: Operating theatres are highly resource-intensive. Their carbon footprint could be reduced by maximising equipment longevity, improving energy efficiency, and renewable energy use. Service delivery Tele-medicine, outreaches, and avoiding desflurane could reduce emissions. Robust surgical systems are required to adapt to the increasing burden of surgically treated diseases, such as injuries from natural disasters. Finance: Climate change adaptation funds could be mobilised for surgical system strengthening. Information systems: Sustainability should be a key performance indicator for surgical systems. Workforce: Surgical providers could change clinical, institutional, and societal practices. Governance: Planning in surgical care and climate change should be aligned. Climate change mitigation is essential in the regional surgical care scale-up; surgical system strengthening is also necessary for adaptation to climate change. Copyright Crown Copyright (C) 2022 Published by Elsevier Ltd.
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| 13. |
- van Zessen, R., et al.
(författare)
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Cue and Reward Evoked Dopamine Activity Is Necessary for Maintaining Learned Pavlovian Associations
- 2021
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Ingår i: Journal of Neuroscience. - : Society for Neuroscience. - 0270-6474 .- 1529-2401. ; 41:23, s. 5004-5014
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Tidskriftsartikel (refereegranskat)abstract
- Associating natural rewards with predictive environmental cues is crucial for survival. Dopamine (DA) neurons of the ventral tegmental area (VTA) are thought to play a crucial role in this process by encoding reward prediction errors (RPEs) that have been hypothesized to play a role in associative learning. However, it is unclear whether this signal is still necessary after animals have acquired a cue-reward association. In order to investigate this, we trained mice to learn a Pavlovian cue-reward association. After learning, mice show robust anticipatory and consummatory licking behavior. As expected, calcium activity of VTA DA neurons goes up for cue presentation as well as reward delivery. Optogenetic inhibition during the moment of reward delivery disrupts learned behavior, even in the continued presence of reward. This effect is more pronounced over trials and persists on the next training day. Moreover, outside of the task licking behavior and locomotion are unaffected. Similarly to inhibitions during the reward period, we find that inhibiting cue-induced dopamine (DA) signals robustly decreases learned licking behavior, indicating that cue-related DA signals are a potent driver for learned behavior. Overall, we show that inhibition of either of these DA signals directly impairs the expression of learned associative behavior. Thus, continued DA signaling in a learned state is necessary for consolidating Pavlovian associations.
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