Sleep disorders and suicidal behavior. Article I: prevalence, impact, and associations

Suicidality and suicide has been associated with many risk factors, while recent clinical and epidemiological studies increasingly point to a potential link between sleep loss or sleep disturbances and suicidality. Considering the high suicide rate and high prevalence of sleep disorders (SD), we conducted this narrative review (1) to estimate the overall association between sleep disorders and suicidal behaviour (SB), (2), to identify a more specific relationship in patients with depression and (3)provide valuable information for clinical practice by exploring the risk difference between various SDand SB(i.e., suicidal ideation and behavior).The potential link between SDand SBhas been the subject of several meta-analyses. Only insomnia and nightmares were found to be statistically associated with an increased risk of suicide. Growing evidence suggests that insomnia is associated with SBindependent of well-established risk factors for suicide, such as depression and hopelessness. These associations generally remained even after adjusting for severity of depression. Insomnia remains an independent indicator of suicidal ideation, even taking into account the core symptoms of depression such as depressed mood and anhedonia. Further research is needed to clarify the specific mechanisms of SDon SB, and more well-designed trials are needed to reduce the risk of SBby improving sleep quality.A more detailed assessment of sleep problems and identification of specific risk domains in primary or secondary prevention of suicidality seem to be a future area of high importance.Assessment and treatment of individual sleep disturbances might represent a personalised preventive measure of suicidality and suicide. Thus, sleep disturbances may qualify as an individual treatable target of evidence-basedpersonalised medicine in the clinical routine as well as in suicide prevention programmes.