Suicidal ideation was common (54%) among primary care patients prescribed treatment for depression but dropped to 30% post-treatment despite minimal clinician contact and the absence of an intervention focused on suicidal ideation. This reduction in suicidal ideation was evident regardless of sex and age. To our knowledge, this is the first study to document an association between iCBT for depression and reductions in suicidal ideation.
The benefits in reducing suicidal ideas are clear. Suicidal behaviour lies on a continuum from thoughts, through intent and planning, to attempt. In the general population it has been shown that 34% of people with ideas develop suicidal plans, and that these plans lead to suicide attempts in 72% of cases.15
That is, one in four people who report suicidal ideation will transition to a suicide attempt, most within the first year of ideation onset.21
Suicide attempts are significant predictors of subsequent completed suicide. Suicidal ideas are distressing and dangerous, and therefore an important target for treatment.
We have conducted two randomised controlled trials of our iCBT programme for depression.1
In the first trial, 33% of applicants were excluded due to suicidal ideation. In the second, 23% were excluded due to suicidal ideation. On the basis of the current results it is now difficult to justify excluding patients from clinical trials on the basis of their high suicidal ideation scores when iCBT can reduce them quickly and effectively.
Although the item from the PHQ-9 assessed the presence and frequency of suicidal ideation, it did not assess the intensity of the ideation, controllability, intention to act on thoughts, nor suicide plans or means. Evidence is also needed to understand whether the changes in suicidal ideation observed in this study are sustained over time. In addition, there was no control sample, meaning that treatment effects could be attributable to regression to the mean, spontaneous remission or placebo effects, rather than the intervention per se. The fact that benefits were observed among patients at different levels of baseline risk indicates that regression to the mean may not underlie treatment effects. However, it is not possible to fully examine the influence of these alternative factors on the outcomes of interest. It was also not possible to establish whether treatment effects were sustained over time due to the lack of follow-up data. Finally, the lack of formal exclusion criteria means that patients may have been using adjunctive treatments which contributed to the magnitude of treatment effects. While the limitations outlined above may be critical within the context of an efficacy trial, they are endemic to effectiveness research.
Both suicidal ideation and depressive symptomatology were reduced considerably following completion of a six-lesson iCBT course for depression. This is the first study to demonstrate this association in primary care. At present, it is routine to exclude patients with frequent suicidal ideation from participating in iCBT. This study provides evidence for change.