Relatively recent research has established sleep problems as an important predictor of elevated suicide risk. Specific aspects of sleep problems that are associated with greater suicide risk are not clear, but insomnia severity, insomnia duration, nightmare severity, and nightmare duration are possibilities. Since there are multiple dimensions of sleep that may play a role in suicide risk, more attention is needed to understand the mechanisms by which sleep influences one’s risk for suicide. The three studies summarized below elucidate the role that nightmares may play in suicide risk as well as the likelihood that individuals experiencing nightmares will inform their healthcare provider. These studies are an important addition to the body of research on the relationship between sleep and suicide risk as researchers attempt to narrow down the role that nightmares play--above and beyond factors such as insomnia and other mental health diagnoses.
The three studies below are listed separately in chronological order, briefly summarized, and a “Clinical takeaways” section follows.
Nardorff, M. S., Nazem, S., & Fiske, A. (2011). Insomnia symptoms, nightmares, and suicidal ideation in a college student sample. Sleep, 34(1), 93-98.
Due to the relationship between sleep problems and suicidal ideation and behavior which has been established in the recent past, the possibility of a link between nightmares and suicidal behavior has also been brought into question. Initial research suggests that nightmares, but not insomnia, are related to suicidal ideation independent of depressive symptoms and other Axis I disorders (this research was conducted when Axial distinctions were used). However, this earlier research did not control for PTSD symptoms or address whether nightmares work through the experience of PTSD or independently. Therefore, the following hypotheses were outlined in this study:
All hypotheses were supported, suggesting that both insomnia symptoms and nightmares are related to suicidal ideation but independently so. Importantly, nightmares, but not insomnia, were found to relate to suicidal ideation independent of depression, anxiety, and PTSD. This is important given that previously it was thought that nightmares may have operated through the larger experience of symptoms seen in PTSD.
Nadorff, M. R., Nazem, S., & Fiske, A. (2013). Insomnia symptoms, nightmares, and suicide risk: Duration of sleep disturbance matters. Suicide and Life Threatening Behavior, 43(2), 139-149.
There is evidence that both insomnia and nightmares are related to suicidal ideation, although their relationship to suicidal ideation differs. The relationship between insomnia and suicidal behaviors has been found to be completely mediated by depressive symptoms whereas nightmares have been found to be associated with elevated suicide risk independent of psychopathology. In an attempt to further clarify the relationship between insomnia symptoms, nightmares, and suicide risk, this study proposed that the duration of symptoms of insomnia and nightmares may be an important determining factor.
This study hypothesized the following:
All hypotheses were supported, suggesting that the duration of insomnia and nightmare symptoms should be considered when considering suicide risk as they both relate independently to risk. Another important finding in this study was the relationship between insomnia symptom duration and suicide risk after depression symptoms were controlled. Since previous research has found that the experience of current insomnia symptoms impacts suicide risk through depressive symptoms, these findings point to another mechanism at work when the duration of insomnia is considered. In other words, the research so far suggests that the chronic experience of insomnia symptoms relates to greater suicide risk above and beyond depression but current insomnia increases suicide risk through depression.
Nadorff, M. R., Nadorff, D. K., & Germain, A. (2015). Nightmares: Under-reported, undetected, and therefore untreated. Journal of Clinical Sleep Medicine, 11(7), 747-750.
Nightmares are not uncommon, with one statistic suggesting 14% of college students reporting a nightmare at least once per week. Also, nightmares are associated with mental health disorders such as PTSD as well as insomnia, anxiety, and depression. Recent studies have shown a relationship between nightmares and suicidal thoughts and behaviors. In spite of this, it appears that nightmares are under-reported by patients, undetected by healthcare providers, and therefore often untreated.
The purpose of this study was to explore what percentage of those who experience nightmares report them to their healthcare provider. In addition, the authors wanted to investigate reasons for the low rates of reporting nightmares.
The findings of the study revealed the following:
Clinical takeaways (in bold):
The three studies summarized here advance our understanding of some important aspects of sleep that relate to suicide risk. As previously believed, insomnia symptoms do contribute to suicide risk, but it may be that the duration of the symptoms of insomnia is a more important factor than the current report of symptoms. Therefore, assessing the duration of insomnia should be specifically addressed along with insomnia severity and other risk factors as part of a comprehensive suicide risk assessment. Nightmares, either alone or in combination with another mental health diagnosis, should be assessed. This is particularly important since most individuals are unlikely to report the experience of nightmares on their own unless the nightmares are severe. If present, specific nightmare treatment is likely indicated in addition to appropriate risk management and treatment of other problems.
Current insomnia symptoms’ relationship to elevated suicide risk is mediated by PTSD, depression, and anxiety. However, insomnia should be treated specifically nonetheless due to the consistent association between insomnia and mental health problems that have been linked to elevated suicide risk.
In summary, sleep problems are a relatively new risk factor on the horizon of the suicide risk literature compared to more familiar ones, such as hopelessness. A number of studies have shown that sleep is an important variable to consider and attend to in suicide risk assessments. However, we have much to learn in terms of the nuances of this, since sleep problems have many different expressions and correlates—nightmares being one of them. The studies above have helped advance the field in that we now have more information about a certain aspect of sleep difficulty—nightmares—to inform clinical practice.
The opinions in CDP Staff Perspective blogs are solely those of the author and do not necessarily reflect the opinion of the Uniformed Services University of the Health Science or the Department of Defense.
Regina Shillinglaw, Ph.D., is a Senior Military Internship Behavioral Health Psychologist with the Center for Deployment Psychology at the Uniformed Services University of the Health Sciences in Bethesda, Maryland. Dr. Shillinglaw is located at Wright-Patterson Medical Center in Ohio.