Seasonal Changes and Decrease of Suicides and Suicide Attempts in France Over the Last 10 Years”.

Abstract

Introduction: The objective of this study was to examine the evolution of suicides and suicide attempts over the last 10 years in France. Methods: We analyzed the number of deaths by suicide and suicide attempts in metropolitan France (2009-2018) from French national databases, on a daily, weekly or monthly basis. Seasonal variation in suicide rates was modeled using a cosinor function. Based on this model, we determined the association of suicides and suicide attempts with geographic characteristics, age, gender, means used and psychiatric disorders. Results: The number of suicides and suicide attempts decreased over the last ten years in France (mean decrease of 14.49% and 11.69% per year). We observed a significant and recurrent seasonal pattern of suicides and suicide attempts in France, with a peak in spring. The suicide and suicide attempt rates were higher in the northern departments of France. Suicides were more frequent for men (75%) and middle-age individuals (45-54 years old), while suicide attempts were more frequent for women (62%) and young adults and middle-age individual (15-19 and 40-49 years old). Nearly two-thirds of the patients who attempted suicide suffered from comorbid psychiatric disorders. Mood disorders was the most frequent comorbid psychiatric disorder (54%). Voluntary drug intoxication was the most common means of suicide attempt (80%), and hanging was the most common means of suicide (54%).Conclusion: The number of suicides and suicide attempts decreased in France over the last 10 years, with large and recurrent seasonal variations. These findings could be used to alert and adjust prevention policies, as well as developing preventive strategies such as chronotherapeutics.

Effects of Intermittent Hypoxia and Electrical Muscle Stimulation on Cognitive and Physiological Metrics

“…This may be attributed to seasonal fluctuations, as the study took place during autumn and spanned a one-month duration. During this period, the day length was reduced by over two hours and the average temperature dropped by 8 • C. There is a growing body of evidence suggesting that seasonality can impact both biochemistry and cognitive measures [41,42]. Specifically, other studies have reported decreased serotonin levels among control groups during the autumn to winter transition, as observed in our study [43,44].…”

“…The signal was divided into periods of 1 s duration; periods with a signal amplitude above 100 µV were excluded. The spectral bands used for further signal processing were delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), beta-1 (12-18 Hz), beta-2 (18-30 Hz), and gamma (30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48).…”