in a large case-control matched study of patients in the Veterans Health Administration database.
However, treatment for sleep disorders was correlated to a reduced risk for suicide attempts.
Todd M. Bishop, PhD
Todd M. Bishop, PhD, of the Center of Excellence for Suicide Prevention, Canandaigua (N.Y.) VA Medical Center, and the department of psychiatry, University of Rochester (N.Y.) Medical Center, and his colleagues wrote that suicide is the 10th most frequent cause of death in the United States, and “nowhere is the suicide rate more alarming than among military veterans, who after adjusting for age and gender, have an approximately 1.5 times greater risk for suicide as compared to the civilian population.”
Previous research has explored the link between sleep disturbances and suicide attempts. But less has been done to look at specific sleep problems, and little research has examined the role of sleep medicine interventions and suicide attempt risk.
The investigators conducted a study to establish the association between suicide attempts and specific sleep disorders, and to examine the correlation between sleep medicine treatment and suicide attempts. Their sample consisted of 60,102 veterans who had received care within the VHA between Oct. 1, 2012, and Sept. 20, 2014. Half of the sample had a documented suicide attempt in the medical record (n = 30,051) and half did not (n = 30,051). The overall sample was predominately male (87.1%) with a mean age of 48.6 years. More than half the sample identified as white (67.4%).
Suicide attempts, sleep disturbance, and medical and mental health comorbidities were identified via ICD codes and prescription records. The predominant sleep disorders studied were insomnia, sleep-related breathing disorder (SRBD), and nightmares. The first suicide attempt in the study period was determined to be the index date for the case-control matching.
Overall, sleep disturbances were much more prevalent among cases than controls (insomnia, 46.2% vs. 12.6%), sleep-related breathing disorder (8.6% vs. 4.8%), and nightmares (7.1% vs. 1.6%). A logistic regression analysis was undertaken to examine the relationship between specific sleep disorders and suicide attempts. Insomnia, nightmares, and SRBD were each associated with increased odds of a suicide attempt with the following odds ratios: insomnia (odds ratio, 5.62; 95% confidence interval, 5.39-5.86), nightmares (OR, 2.49; 95% CI, 2.23-2.77), and sleep-related breathing disorder (OR, 1.37; 95% CI, 1.27-1.48).
A second model included known drivers of suicide attempts (PTSD, depression, anxiety disorders, schizophrenia, bipolar disorder, substance use disorder, medical comorbidity, and obesity). But after controlling for these factors, neither nightmares (OR, 0.96; 95% CI, 0.85-1.09) nor sleep-related breathing disorders (OR, 0.87, 95% CI, 0.79-0.94) remained positively associated with suicide attempt, but the association of insomnia with suicide attempt was maintained (OR, 1.51; 95% CI, 1.43-1.59).
The question of the impact of sleep medicine interventions on suicide attempts was studied with a third regression model adding the number of sleep medicine clinic visits in the 180 days prior to the suicide attempt index date as an independent variable. The variables in this model were limited to insomnia, SRBD, and nightmares. The investigators found that “for each sleep medicine clinic visit within the 6 months prior to index date the likelihood of suicide attempt is 11% less (OR, 0.89; 95% CI, 0.82-0.97).”
The limitations of the study include the lack of information on sleep treatment modalities or medications provided during the clinic visits, and the overlapping of sleep disturbance with other mental health conditions, such as alcohol dependence and PTSD. In addition, “some insomnia medications are labeled for risk of suicidal ideation and behavior, so there is some chance that the medications rather than insomnia itself were associated with the increased suicidal behavior,” the investigators wrote.
In addition to an analysis of specific types of sleep disorders associated with suicide attempts, the study showed that treatment of sleep disorders may have an important role in suicide prevention. The investigators concluded: “Identifying populations at risk for suicide prior to a first attempt is an important, but difficult task of suicide prevention. Prevention efforts can be aimed at modifiable risk factors that arise early on a patient’s trajectory toward a suicide attempt.”
The study was supported by the VISN 2 Center of Excellence for Suicide Prevention, Canandaigua VAMC. The authors had no disclosures.
SOURCE: Bishop TM et al. Sleep Med. 2019 Jul 25. doi: 10.1016/j.sleep.2019.07.016.