• Bibtex: @freichel2023
  • Bibliography: Freichel, R., & O’Shea, B. A. (2023). Suicidality and mood: The impact of trends, seasons, day of the week, and time of day on explicit and implicit cognitions among an online community sample. Translational Psychiatry, 13(1), Article 1. https://doi.org/10.1038/s41398-023-02434-1

Example citation

The interaction of reduced ideation, increased energy, and improved mood may put individuals within a high threshold of high risk of suicide during spring

My notes

We believe the most crucial finding from our analysis is the rise in negative mood and desire to die, especially among suicide attempters, occurring approximately three to four months before (December) the yearly seasonal peak of suicide attempts and deaths in spring and early summer.

Why is this? If someone is severely depressed during the winter, once spring comes they may get more energy faster than their mood improves. This means more energy to contemplate and plan suicide.


Decades of research have established seasonality effects on completed and attempted suicides, with rates increasing in spring. Little advancements have been made to explain this phenomenon, with most studies focusing almost exclusively on the number of suicide attempts and deaths. Using more than six years of data collected among a US, UK, and Canadian online community sample (N > 10,000), we used newly developed Prophet forecasting and autoregressive-integrated moving average time-series models to examine the temporal dynamics of explicit and implicit self-harm cognitions. We created three groups (past suicide attempters; suicide ideation and/or non-suicidal self-injury; no previous self-harm, suicidal thoughts, or behaviors). We found a general increase of negative self-harm cognitions across the six years and seasonality effects for mood and desire to die, particularly among those who previously made a suicide attempt. Negative explicit self-harm cognitions peaked in winter (December), with implicit self-harm showing a lagged peak of two months (February). Moreover, daily negative self-harm cognitions consistently peaked around 4–5 am, with implicit cognitions again showing a lagged effect (1-hour). Limitations include the volunteer sample not being representative and the cross-sectional nature of the data being unable to separate between-subject and within-subject structural trends in the time series. Our findings show that negative explicit and implicit cognitions precede the rise in suicidal behaviors in spring. We proposed a conceptual model of seasonal suicide risk that may offer fertile ground for theoretical advancements, including implications for clinical risk assessment and public policies regarding the availability of health services. PDF: freichel_2023_suicidality_and_mood_-_the_impact_of_trends,_seasons,_day_of_the_week,_and_time.pdf