Burden of Insomnia Among Individuals With Major Depressive Disorder: Cross-Sectional Observational Study.

Background: Insomnia is a common and persistent symptom in major depressive disorder (MDD), associated with poorer outcomes and reduced quality of life (QoL). Despite its prevalence, recent patient-reported data on the burden of insomnia symptoms in MDD remains limited. Objective: This study aimed to assess the burden of insomnia among individuals with MDD experiencing insomnia symptoms (MDDIS) and its impact on patient-perceived disease burden and QoL. Methods: A noninterventional, cross-sectional online study was conducted from October 2022 to February 2023 in adults with self-reported MDD and insomnia symptoms, residing in the United States or 1 of 5 European countries (EU5: France, Germany, Italy, Spain, and the United Kingdom). Participants completed validated questionnaires (Patient Health Questionnaire-9 [PHQ-9] for depression severity and Insomnia Severity Index [ISI] for insomnia severity) and provided data on demographics, clinical history, treatment experience, and perceptions. Descriptive statistics were used to summarize results, and subgroup analyses were conducted based on depression status and severity. Results: Among 1250 participants (United States: 500; EU5: 750), most were cisgender women (United States: 363/500, 72%; EU5: 637/750, 85%), aged ~48 years, and on average 13.4 years in the United States and 11.2 years in EU5 had passed since being diagnosed with MDD. Around 60% (United States: 312/500; EU5: 439/750) reported having moderate to severe insomnia symptoms. Most had used antidepressants (United States: 460/500, 92%; EU5: 646/750, 86%) at least 40% (United States: 198/500; EU5: 343/750) in both regions reported using sleep-related medications (over-the-counter sleep aids, dual-purpose medication, or sleep-specific medication). However, insomnia symptoms persisted, with around half of participants reporting 8 to 15 insomnia nights over 2 weeks. Insomnia symptom severity differed significantly according to depression severity and current depressive episode status. Nearly all participants reported negative consequences for daily functioning, including irritability, cognitive impairment, and reduced productivity, and approximately two-thirds identified sleep disturbances as having a major impact on their daily lives. Satisfaction with current treatments, particularly their effectiveness on sleep, was low, and 65%-71% (488/750-354/500) of participants expressed a desire for alternative therapies. Conclusions: Insomnia symptoms are highly prevalent and burdensome among patients with MDD, severely affecting daily life and perceived treatment success. Insomnia remains inadequately controlled despite high medication use. These findings emphasize the need for integrated treatment strategies targeting both mood and sleep symptoms. Given its role in depression relapse, suicidality, and treatment resistance, addressing insomnia symptoms in MDD should be a clinical priority.