Agitation as a Moderator of the Relationship Between Insomnia and Current Suicidal Ideation in the Military

Abstract

Research has established a link between agitation and insomnia, both of which are considered to be risk factors for suicide. The present study aimed to investigate the moderating role of agitation within the relationship between insomnia and current suicidal ideation in a sample of U.S. military personnel. Consistent with hypotheses, the relationship between insomnia and current suicidal ideation was significant only at high levels of agitation. Results support previous findings indicating that both insomnia and agitation are suicide risk factors. These findings clarify the role of known risk factors in the pathway to suicide and may contribute to the advancement of suicide detection and prevention, as these factors may be more easily identified in individuals unwilling to admit thoughts of death and suicide, such as many military personnel.

Keywords:

• agitation
• insomnia
• military
• risk factors
• suicide

Notes

¹To ensure that results were not spuriously influenced by covariates, we re-ran our analysis without including any covariates. Results remained significant in the same direction.

²The amount of missing data varied from measure to measure in our sample, with a maximum of 20% missing (insomnia total scores missing due to sporadic missing items). Analyses indicated these data points were missing completely at random. To account for this, we re-ran our analyses using multiple imputation procedures. Results were unchanged, with the interaction of insomnia and agitation still significantly predicting suicidal ideation (b = .004, SE = .001; t = 3.11, p = .004).

³The DSI-SS is used less frequently as a measure of ideation than is the BSS. Furthermore, the inclusion of the DSI-SS in our safety protocol could have potentially spuriously influenced our results. To control for this, we re-ran our analyses using the first 19 items of the BSS as our outcome rather than the DSI-SS. The interaction of insomnia and agitation significantly predicted suicidal ideation as measured by the BSS (b = .008; SE = .001; p < .0001) and the association between insomnia and suicidal ideation again increased in magnitude from low (t = .57; p = .565) to mean (t = 3.13; p = .002) to high (t = 6.28; p < .0001) levels of agitation.

Additional information

Notes on contributors

Karin Fisher

Karin Fisher, Department of Psychology, University of Southern Mississippi, Hattiesburg, Mississippi, USA.

Claire Houtsma

Claire Houtsma, Department of Psychology, University of Southern Mississippi, Hattiesburg, Mississippi, USA.

Brittney L. Assavedo

Brittney L. Assavedo, Department of Psychology, University of Southern Mississippi, Hattiesburg, Mississippi, USA.

Bradley A. Green

Bradley A. Green, Department of Psychology, University of Southern Mississippi, Hattiesburg, Mississippi, USA.

Michael D. Anestis

Michael D. Anestis, Department of Psychology, University of Southern Mississippi, Hattiesburg, Mississippi, USA.