New research looks into dreams monitoring for suicide prevention
Changes in dreams could predict a suicidal crisis. This warning sign is particularly easy to look for in clinical practice.
Nightmares: the most reliable predictor of suicide risk
Over the past decade, there has been increasing research into the links between recurrent nightmares or insomnia and the risk of suicide.
There is a well-known association between nightmares and major depressive disorder. However, it is not clear whether nightmares are an independent risk factor for suicidal behaviour or whether this association is mediated by depression.
In 2011, a study1 showed that nightmares are the most reliable predictor of suicide risk, independently of other factors. The hypothesis was that, in addition to symptoms of insomnia, depression, anxiety, or post-traumatic stress disorder, the presence of nightmares may add further distress, leading to an increase in suicidal ideation.
In a later research study2, the same authors suggested that the duration of sleep disturbance is relevant in assessing suicide risk. For Professor of Psychology Michael R. Nadorff, lead author of the study, "insomnia and nightmares are more strongly associated with suicide risk the longer they last".3
In 2021, a large study4 involving more than 40,000 participants, with an average follow-up time of 19 years, concluded that nightmares have no influence on the incidence rate of suicide, but that they may reflect pre-existing depression.
Can nightmares predict suicidal behaviour?
Asking a patient about his or her dreams, and their possible modification is very easy to do. In the context of preventing a suicidal crisis, it would therefore be valuable for doctors to know whether nightmares can constitute a reliable warning signal.
This is supported by two recent studies. The first, from 2021, looked at adolescents leaving acute psychiatric care.5 An association between sleep disorders (such as ruminative thoughts before falling asleep and nightmares) and suicidal thoughts occurring the next day was demonstrated. These disorders can therefore be considered as a short-term risk factor for suicidal thoughts.
The second French study6 was published at the end of 2022 in The Journal of Clinical Psychiatry. It focused on the chronological evolution of nightmares, their content and intensity, during the months preceding a suicidal crisis.
Progressive dream impairment
In this naturalistic study of 40 suicide attempters, 80% of them (N=32) reported that they had experienced an alteration in their dreams before a suicidal crisis. For 21 people, these were nightmares, defined here as dreams so terrifying that they woke the person up (as opposed to dysphoric dreams or "bad dreams").
The authors were able to identify a chronological progression: the "bad dreams" present 4 months before the suicide attempt became nightmares 3 months before this crisis. Nine people reported that repeated suicide scenarios appeared in their dreams on average 45 days before the attempt.
Almost all of these patients (97.5%) had depressive symptoms. The vast majority of these symptoms were rated as moderate to severe. 60% of the participants reported insomnia and 92.5% of them had impaired sleep quality.
Implications for medical practice
For the lead author, psychiatrist and sleep physician Pierre A. Geoffroy, bad dreams are linked to suicide because the person's emotional response is similar whether asleep or awake.7
Geoffroy points out that there is currently no sufficiently reliable tool that can detect the warning signals of a suicidal crisis on its own. However, he believes that screening for dream alteration could be effective, particularly in an emergency context.
More generally, the detection of a suicidal crisis would be facilitated if doctors knew precisely which types of sleep disorders are particularly worrying. Thus, the classic questions such as "Do you sleep well" or "Are you undergoing insomnia" could be advantageously replaced by precise questions on the evolution of the nature of dreams and their content.
- Nadorff MR, Nazem S, Fiske A. Insomnia symptoms, nightmares, and suicidal ideation in a college student sample. Sleep. 2011 Jan 1;34(1):93-8. doi : 10.1093/sleep/34.1.93. PMID : 21203379 ; PMCID : PMC3001802.
- Nadorff MR, Nazem S, Fiske A. Insomnia symptoms, nightmares, and suicide risk: duration of sleep disturbance matters. Suicide Life Threat Behav. 2013 Apr;43(2):139-49. doi: 10.1111/sltb.12003. Epub 2012 Dec 28. PMID: 23278677; PMCID: PMC3609914.
- Sarah Fowler | The Clarion-Ledger. “MSU professor links nightmares to suicide risk”.
- Anna Karin Hedström, Rino Bellocco, Ola Hössjer, Weimin Ye, Ylva Trolle Lagerros, Torbjörn Åkerstedt. The relationship between nightmares, depression and suicide. Sleep Medicine, Volume 77, 2021, Pages 1-6. Link: doi.org/10.1016/j.sleep.2020.11.018.
- Glenn, C., Kleiman, E., Kearns, J., Boatman, A., Conwell, Y., Alpert-Gillis, L., & Pigeon, W. (2021). Sleep problems predict next-day suicidal thinking among adolescents: A multimodal real-time monitoring study following discharge from acute psychiatric care. Development and Psychopathology, 33(5), 1701-1721. doi:10.1017/S0954579421000699
- Geoffroy PA, Borand R, Ambar Akkaoui M, Yung S, Atoui Y, Fontenoy E, Maruani J, Lejoyeux M. Bad Dreams and Nightmares Preceding Suicidal Behaviors. J Clin Psychiatry. 2022 Nov 23;84(1):22m14448. doi: 10.4088/JCP.22m14448. PMID: 36416752.
- “Timing, Content of Bad Dreams May Help Predict Suicide” (November 2022)