We congratulate Littlewood et al. for their important work showing that the relationship between nightmares and suicide is mediated in part by the psychological constructs of defeat, entrapment, and hopelessness.1 However, they err in asserting that no prior “work [has] elucidated the psychological mechanisms which underpin” the relationship between sleep problems and suicidal behaviors. Three years ago, our group reported in this same journal the results of a mediation path analysis regarding the relationship between insomnia and suicidal ideation.2 Consistent with Littlewood et al., we found that nightmares were an important factor mediating the role of insomnia in posing risk for suicidal ideation. We also found a near-significant trend for Dysfunctional Beliefs and Attitudes About Sleep in serving as a mediator between insomnia and suicidal ideation. Elsewhere we have also posed a series of psychological and biological mechanisms worthy of investigation in explaining the association between sleep problems and suicide.3 We also agree with Littlewood et al.'s statement of need for longitudinal studies of insomnia/nightmares/sleep problems as possible modifiable risk factors in suicide risk mitigation. Indeed, we are undertaking such as study now.4 The association between sleep problems and suicide has been described in more than 60 observational studies—it is time to move forward to interventional studies.5
This was not an industry supported study. The authors have indicated no financial conflicts of interest.
McCall WV. Mediators between sleep problems and suicide: response to Littlewood et al. J Clin Sleep Med 2016;12(6):929.
Littlewood DL, Gooding PA, Panagioti M, et al., authors. Nightmares and suicide in posttraumatic stress disorder: the mediating role of defeat, entrapment, and hopelessness. J Clin Sleep Med. 2016;12:393–9. [PubMed]
McCall W, Batson N, Webster M, et al., authors. Nightmares and dysfunctional beliefs about sleep mediate the effect of insomnia symptoms on suicidal ideation. J Clin Sleep Med. 2013;9:135–40. [PubMed Central][PubMed]
McCall W, Black C, authors. The link between suicide and insomnia: theoretical mechanisms. Curr Psychiatr Rep. 2013;15:389.
McCall W, Benca R, Rosenquist P, et al., authors. A multi-site randomized clinical trial to reduce suicidal ideation in suicidal adult outpatients with major depressive disorder: development of a methodology to enhance safety. Clin Trials. 2015;12:189–18. [PubMed]
McCall W Vaughn. Insomnia is a risk factor for suicide - what are the next steps? Sleep. 2011;34:1149–50. [PubMed Central][PubMed]