Using daily diary data to examine the period prior to a suicide attempt: An observational single-case study

Background: Prevention of suicide is an important public health issue. Applying Exponential Weighted Moving Average (EWMA) control charts to time-intensive diary data could improve our understanding of the processes leading up to a suicide attempt (SA). We explored daily reports of multiple psychopathological domains, and particularly changes therein, during a period directly preceding a SA.

Methods: We applied an observational single-case study design on a diary data from one participant (female, age between 20 and 30 years) who attempted suicide (and survived) during participation in another study. This study included 90 daily reports of depression and anxiety symptoms, psychotic experiences, thought disturbances and a proxy for passive suicide ideation (feeling life is worthwhile). We used EWMA control charts to explore whether structural changes in these psychopathological domains preceded the upcoming SA. We first investigated the overall domains and then zoomed in on individual items.

Results: We detected increases in depression and anxiety symptoms, psychotic experiences, and passive suicide ideation in a time window of 6 days directly preceding the SA. Although no changes in the overall dimension of thought disturbances preceded the SA, two specific items, impulsive thoughts and persistent thoughts, did increase.

Conclusion: We found changes in daily reports of several (sub)dimensions of psychopathology prior to the SA. Our findings show how applying EWMA charts to diary reports may be helpful to detect signs of an upcoming SA. Improving our ability to timely signal risk for SA may inform strategies aimed at its prevention.