Background: Studies in the northern and southern hemispheres consistently identified seasonal influences on monthly and semester suicide distribution. The variations of sunlight exposure in zones of increasing latitude has been suggested as one of the most plausible explanations for this phenomenon. Some recent studies in the northern hemisphere could not find seasonal asymmetries of suicides. The current study examines the monthly, seasonal and semester distribution of suicidal deaths in Chile and the influence of seasons in zones of low latitude as compared with regions of high or very high latitude, trying to determine if a seasonal pattern still exists in a country of the southern hemisphere. Methods: Monthly, seasonal and semester suicidal data over the period 1995–1999 were examined for the whole sample and for gender-specific subgroups in Chile. Four different latitudinal zones were analyzed separately, in order to investigate the effect of the photoperiod on suicide distribution. Results were analyzed by χ² tests for multinomials, as an overall measure of deviation. Results: We found a significant unimodal springtime peak for both genders in the global territory. Among the 4,710 male and 829 female suicides reported in this period there were no gender differences in the seasonal pattern of suicidal deaths. When divided into four different latitudinal zones, the regions with low latitude (north of the country) showed no significant differences, while central and southern zones (higher latitude) show a significant springtime pattern. In the extreme south of the country, no significant differences were found, probably due to the very small number of cases. Conclusion: The study confirms the existence of a unimodal springtime peak of suicides in Chile, but not in the zone of low latitude. Results support the notion that the seasonal impact on suicidal distribution is a function of photoperiod.

Background The consumption of psychotropic drugs without a medical prescription is a growing public health problem worldwide. Misuse or indiscriminate use involves several risks. Objective To determine sociodemographic factors and behaviors associated with the consumption of psychotropic drugs without prescription in Chile. Methods This is a descriptive study based on the data of the XI National Study of Drugs in the General Population in Chile, carried out in the population between 12 and 64 years old (n = 19 512) during 2014. Prevalence was estimated, and a multivariate logistic regression model was adjusted. Also, a multiple correspondence analysis was performed. Results The prevalence of psychotropic drug use was 2.3%. In the studied population, associated risk factors are female sex (odds ratio: 1.4; 95% confidence interval: 1.16 to 1.77); ages between 20-29 (odds ratio: 1.4; 95% confidence interval: 0.98 to 2.26) and 40-49 (odds ratio: 1.8; 95% confidence interval: 1.19 to 2.75); consumption of marijuana (odds ratio: 3.0; 95% confidence interval: 3.32 to 3.97), cocaine or crack (odds ratio: 3.7; 95% confidence interval: 2.45 to 5.70); tobacco (odds ratio: 1.4; 95% confidence interval: 1.17 to 1.78); alcohol (odds ratio: 1.3; 95% confidence interval: 1.11 to 1.73); and poor health perception (odds ratio: 1.8; 95% confidence interval: 1.51 to 2.28). Military personnel used more pain and cough medication; young women between 19 to 25 years old used stimulants; the population between 45 to 64 years had a bad perception of health associated with the use of tranquilizers; and men between 12 and 18 years used illicit drugs. Conclusions The prevalence found in the different groups is consistent with data reported in Latin America, showing the relationship between the use of non-prescription psychotropic drugs with sociodemographic factors, risk behaviors, and the identification of consumption profiles.