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- Bauer, Michael, et al.
(author)
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Association between solar insolation and a history of suicide attempts in bipolar I disorder.
- 2019
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In: Journal of psychiatric research. - : Elsevier BV. - 1879-1379 .- 0022-3956. ; 113, s. 1-9
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Journal article (peer-reviewed)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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| 2. |
- Cakmakli, Gül Yalcin, et al.
(author)
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Spectral Analysis of Lithium Tremor
- 2021
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In: Archives of Neuropsychiatry. - : Turk Noropsikiyatri Dernegi. - 1309-4866. ; 58, s. 268-273
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Journal article (peer-reviewed)abstract
- Introduction: Lithium has proven efficacy in bipolar affective disorder (BAD) but induces tremor as a side effect in a quarter of patients. Lithium tremor (LT) shares some clinical characteristics of essential tremor (ET) and Parkinson’s disease tremor (PT), which might cause difficulties in differential diagnosis. Furthermore, current knowledge of LT is lacking detailed electrophysiological characterization. Here, we present detailed spectral attributes of accelerometric tremor recordings as a diagnostic tool for LT. Methods: 10 patients (7 males, 3 females) between ages of 29–68, who were on lithium for BAD for 2–12 years, were evaluated for hand tremor with the spectral analysis of accelerometric recordings with different postures. Tremor severity was rated clinically on WHIGET (Washington Heights-Inwood Genetic Study of Essential Tremor) scale. Results were analyzed in comparison to results of ET (n=19) and PT (n=19) patients from our database. Results: LT was most prominent at extensor postures with an average peak frequency (PF) of 8.0±0.3 Hz and an extremely low amplitude, high harmonic components and high noise level. The average PF of LT was similar to that of ET (7.3±0.4 Hz), but higher than that of PT (5.3±0.2 Hz) (p<0.0001). With weight loading, the PF of LT showed an increase of 1.3 Hz. Average amplitude of PT was higher than that of both LT and ET (p<0.0001); harmonic components of LT was comparable to PT whereas noise levels were similar to that of ET. Mean WHIGET score of LT (6.5±0.5) was significantly lower than that of ET (13.1±1) (p<0.0001). Conclusion: Electrophysiological features detected by accelerometry may help in differential diagnosis of LT from ET and PT. Keywords: Lithium tremor, accelerometry, tremorogram, peak frequency, harmonic components
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