Suicide is a serious social and public health problem, estimated to cause the death of at least 720,000 people worldwide each year and a much larger number of those affected, including those who have suffered the irreparable loss of a loved one. In Spain last year at least 3,952 people died as a result of suicide, a figure that hides tragedies that no statistic can fully reflect.

Suicidal thoughts and behaviour and mortality from suicide particularly affect those suffering from certain mental disorders such as depression, psychosis or addictions, so an effective suicide prevention policy must include improving the detection and treatment of mental health problems that pose a greater risk of suicide. We also know that suicidal behaviours do not depend exclusively on individual characteristics that can be modified with clinical interventions, but are also associated with environmental and social determinants that require a public health approach that goes beyond a purely health care response.

Suicide mortality is known to be higher at certain times of the year and may be unevenly distributed across days of the week. The heterogeneous distribution of suicide deaths could be due to factors such as changes in atmospheric temperature or the length of day and night - which affect our biology and may modify the expression of some diseases - as well as to social or cultural factors that vary between countries. To better assess these temporal patterns in suicide mortality, the authors of the study published in the BMJ analysed data on more than 1.7 million fatal suicides recorded between 1971 and 2019 in 740 locations in 26 different countries. The researchers were able to find that, despite other important differences in the temporal patterns of suicide mortality between countries, there was a significant increase in the number of fatal suicides on Mondays compared to other weekdays, and lower proportions of deaths on weekends. An increase in fatal suicides was also observed on New Year's Day in most of the countries included in the study.

Beyond providing some interesting data on a serious problem such as suicide, the results of this study are of interest because they highlight the role of its social determinants. The authors outline some of the factors that could explain why there are more suicides on Mondays and New Year's Day, such as the ‘broken promise effect’ that many people experience when they are re-exposed to the stressful conditions of working life at the end of the weekend or after failing to keep the good resolutions that often mark the end of the year. Increased alcohol use and other variables strongly associated with suicide such as lack of social support and gender differences may also contribute to explain the temporal variations in mortality that this study seems to confirm.

Why is it important to study which days of the week or holiday periods have a higher risk of suicide? 'It is of great relevance to study the risk factors in order to carry out adequate prevention with a greater focus on the most vulnerable population. In this line, resource management could also benefit from the results, since it is possible to identify the times when more resources are required and to provide them to the population. Another relevant aspect of studying the day of the week with the highest risk of suicide is the possibility of rethinking our lifestyle in relation to the routines we have, both at an educational and work level. Returning to the issue of prevention and in line with the finding of an increased risk of suicide on holidays such as New Year, it can be of great help in developing prevention programmes and campaigns on these dates, as well as providing a greater number of tools and resources for care on these holidays to people who are at risk of suicidal behaviour’.

Is the study of good quality? ‘It is a good quality study because it includes the analysis of several countries with cultural differences, which helps us to reach more global and inclusive conclusions. It also looks at various time periods, which helps to take into consideration different historical moments, both in terms of social events and also the passage of time as people grow older. Another interesting feature of this study is the size of the sample: this article analyses 1,701,286 cases. Such a large sample in the field of suicide is to be welcomed, as it is not usually easy to collect and access these data due to the sensitivity of the subject and also because, in some cases, records are not kept in a clear, timely and adequate manner'.

Do you have any notable limitations? ‘I would like to highlight one of the main limitations mentioned by the authors; caution is needed when interpreting the results as, although they include many countries, it is not advisable to extrapolate them because it is necessary to take into consideration different cultural characteristics, different ways of relating, variability in dates of festivities, diversity of religions and beliefs, and a wide range of health systems, as well as different protocols for the collection of suicide data’.

It is important to know the days on which the risk of suicide increases because, in this way, preventive strategies can be put in place by health professionals or by the health system (through ICT or other strategies).
In order to do this, it is essential to have sufficient access and knowledge (and resources) to be able to act with these people who are at increased risk of suicide.

Is the studio of good quality? ‘It is'.

Does it have any notable limitations? ‘Suicide statistics are not very reliable. Not all cultures or countries or years are represented. There are ‘nitreal’ variations in suicide rates that are not taken into account. There are risk factors for suicidal behaviour, such as alcohol consumption, which may explain this relationship. From a public health point of view, limitations on the distribution and timing of consumption could help to reduce rates. There are more than 800,000 suicide deaths per year; this gives an idea of the representativeness of the study (only 4 % of the suicides that occurred in that time)'.