Years ago, when I was on active duty, I was called to serve as the psychologist on a Root Cause Analysis (RCA). An RCA is a multidisciplinary systemic investigation into what happened leading up to a sentinel event, why it happened, and what could be done differently in future similar events. The sentinel event in this case was a recent suicide of a Service member at the installation. While every suicide is a unique loss, this loss crosses my mind frequently. The husband and his wife, who had two young children, had been having relationship difficulties. They returned home very late one night from a date night and began to argue. As the argument escalated, he took out his gun, and his wife rushed the children out of the room before he fatally shot himself. Although there were many precipitating factors, primarily including marital distress, I have often wondered – would it be different if this had happened during the day? Did he feel it was so late he had no one to call and nowhere to go? Was he tired and exhausted?
It was only relatively recently that a connection between sleep disturbance and suicide – including ideation, attempts, and deaths– was explored. Early studies found connections among both civilian and military-connected populations (Pigeon et al 2012; Ribeiro et al, 2012). Specific aspects of sleep disturbance that have so far been found to be relevant include difficulty falling and staying asleep, nightmares, and sleep variability.
A few years ago, a group of researchers out of the University of Pennsylvania began to wonder if part of the relationship between sleep disturbance and suicide risk had to do with being awake at night, particularly those very early morning hours – or very, very late night hours depending on your perspective – where the circadian rhythm hits a ‘trough’. It makes sense for a number of reasons. If you’re awake in the middle of the night, you may feel isolated and that you cannot reach out to anyone as your friends and family are likely to be asleep. Moreover, in that circadian trough, your frontal lobe function is decreased, making it harder to solve problems so they may seem too overwhelming to manage, and increasing the risk for impulsive actions. You may be up late due to substance use which in itself exposes one to risk factors. Despite these potentially problematic issues, early research surprisingly found no increased risk of suicide at night and instead found a higher number of suicides during the day.
But none of those studies realized that there are more people awake during the day than the night so of course the raw numbers would be higher. What if instead the risk of suicide across 24 hours was considered as a prevalence rate…that is, of the people awake at any given time, how many of those die by suicide?
With that consideration, data on thousands who had died by suicide was analyzed, and the peak frequency of suicide was actually found to occur at 2 a.m., with the highest times ranging between 12 and 4 a.m.. Frequency during daytime hours were relatively flat in comparison.
A similar study that same year that just evaluated patients with major depression and Bipolar Disorder found that very late night/early morning wakefulness, specifically pinpointed as at 4 a.m., was associated with increased suicidal ideation the next day (Ballard et al, 2016).
While there is no single solution to reducing the rate of suicide, it is clear that along with a multitude of other factors such as psychological co-morbidities, relationship stress, financial stress, social support, cultural and demographic background (see my colleague Erin Frick's blog on this topic here), and means availability, one factor that should be considered is nighttime wakefulness. Both population wide interventions such as the development of community resources available at night and individual interventions, such as Cognitive-Behavioral Therapy for Insomnia (CBT-I), could be considered as preventive strategies. If you are a clinician reading this who works with patients at elevated risk for suicide, I recommend you discuss with them how those late night hours could be a time of particular vulnerability. Also consider evaluating and treating any sleep disturbance with an evidence based approach such as CBT-I. More than simply the absence of wakefulness, sleep is a key element to our daily lives - improving sleep could be life-saving for those in distress.
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.
Diana Dolan, Ph.D., CBSM, is a clinical psychologist serving as a Senior Military Behavioral Health Psychologist with the Center for Deployment Psychology at the Uniformed Services University of the Health Sciences in Bethesda, Maryland.
Ballard, E.D., Vande Voort, J.L., Bernert, R.A., Luckenbaugh, D.A, Richards, E.M., Niciu, M.J., Furey, M.L., Duncan, W.C. & Zarate, C.A. (2016). Nocturnal wakefulness is associated with next-day suicidal ideation in major depression and bipolar disorder. Journal of Clinical Psychiatry 77(6): 825-831. doi:10.4088/JCP.15m09943
Perlis, M.P., Grandner, M.A., Brown, G.K., Basner, M., Chakravorty, S., Morales, K.H., Gehrman, P.R., Chaudhary, N.S., Thase, M.E., & Dinges, D.F. (2016). Nocturnal Wakefulness: A Previously Unrecognized Risk Factor for Suicide. Journal of Clinical Psychiatry 77(6): e726-e733.
Pigeon, W.R., Pinquart, M., Conner, K. (2012). Meta-analysis of sleep disturbance and suicidal thoughts and behaviors. Journal of Clinical Psychiatry 73(9): e1160-e1167.
Ribeiro, J.D., Pease, J.L., Gutierrez, P.M., Silva, C., Bernert, R.A., Rudd, M.D., & Joiner, T.E. (2012). Sleep problems outperform depression and hopelessness as cross-sectional and longitudinal predictors of suicidal ideation and behavior in young adults in the military. Journal of Affective Disorders 136: 743-750. doi:10.1016/j.jad.2011.09.049