663 Improved Sleep After a Brief Intervention for Insomnia Mediates Improvements in Depression Symptoms During the COVID-19 Pandemic

Abstract

IntroductionThe COVID-19 Pandemic and mitigation efforts have led to drastic increases in acute insomnia symptoms, which left untreated may contribute to increased risk for other negative mental health outcomes, including depression. However, the impact of treating acute insomnia symptoms on future depression outcomes remains unknown. Moreover, whether sleep improvements as a result of an insomnia treatment mediate subsequent reduction of depression symptoms similarly remains unknown.MethodsAt this writing, 44 individuals experiencing insomnia symptoms (Insomnia Severity Index; ISI ≥ 10) that began during the COVID-19 pandemic have been randomized to receive a brief, telehealth Cognitive Behavioral Therapy for Insomnia (CBTI) waitlist control. Treatment was delivered in 4 sessions over a 5-week period. CBTI is the gold-standard behavioral intervention for chronic insomnia and has been applied successfully via telemedicine. Outcome measures were depressive symptoms as measured by the Patient Health Questionnare-9 (PHQ-9) minus the sleep item and insomnia symptom severity as measured by the ISI. Both outcome measures were collected at baseline (week 0), throughout treatment phase (weeks 2–6), and at the post-treatment (week 7). Linear mixed models determined the impact of treatment on depression and insomnia symptom severity. Mediation was tested using the MacArthur framework.ResultsThere was a significant Group x Time interaction, with CBTI leading to a greater rate of improvement in ISI (b = -1.14, p < 0.001) and PHQ-9 (b = -0.61, p = 0.002) than the control. Critically, the rate of improvement in insomnia symptoms to the last session of treatment, was associated with the subsequent improvement in depressive symptoms post-treatment (b = 2.06, p = 0.017). In contrast, depressive symptom improvement was not associated with insomnia symptom improvement (b = 4.28, p = 0.102).ConclusionThis preliminary data suggests that brief CBTI can reduce pandemic onset insomnia and other depressive symptoms. The preliminary mediation results further suggest that sleep may be an important treatment target for reducing situational depressive symptoms and supports the need to examine the physiological mechanisms of sleep using high-density EEG in a larger sample.Support (if any):