Moderating effects of sleep difficulties on relations between posttraumatic stress disorder symptoms and positive memory count

Abstract

Objectives: Posttraumatic stress disorder (PTSD) severity relates to positive memory retrieval difficulties. One variable potentially influencing this relation is sleep difficulties. We examined moderating effects of sleep difficulties (duration and quality) on relations between PTSD severity and count of specific positive memories covarying for age, gender, and depression.

Methods: Participants were an Amazon Mechanical Turk-recruited trauma-exposed community sample of 205 respondents (M _age = 35.44; 61.40% women).

Results: Moderated regression analyses indicated significant interaction effects between sleep quality (b = 0.03; p = 0.036) and PTSD severity on specific positive memory count. Among individuals reporting better sleep quality, there were negative associations between PTSD severity and specific positive memory count (b = -0.04, SE = 0.02, p = 0.010). Similar results were obtained for PTSD's intrusion and arousal clusters.

Conclusion: Results support targeting sleep quality and PTSD severity to improve positive memory retrieval in PTSD and memory interventions, and the importance of considering sleep when examining links between PTSD and positive memory retrieval.

Keywords: count of specific positive memories; moderation analyses; posttraumatic stress disorder; sleep; trauma-exposed community sample.

Figure 1.

Moderating impact of sleep quality in the relation between PTSD symptom severity and specific positive memory count. Note. PSQI is the Pittsburgh Sleep Quality Index; PCL-5 is the Posttraumatic Stress Disorder Checklist for DSM-5; Simple slopes are shown at the mean and at +/− 1 standard deviation (SD) above and below the mean of sleep quality. For sleep quality, higher values indicate poorer sleep. Both the PSQI and PCL-5 were centered at the mean.

Figure 2.

Johnson-Neyman plot for probing the moderating effects of sleep quality on the association between PTSD symptom severity and specific positive memory count. Note. PSQI is the Pittsburgh Sleep Quality Index; PCL-5 is the Posttraumatic Stress Disorder Checklist for DSM-5; When PSQI Sleep Quality (centered) is outside the interval −0.16 to 11.11, the slope of PCL-5 Total Score and Positive Memory Count is p < .05. The range of observed values of PSQI Sleep Quality (centered) is −1.15 to 1.85.