0323 Natural Evolution of Insomnia in Major Depressive Disorders

Abstract

Abstract Introduction Insomnia is a fairly common sleep disturbance affecting nearly one third of the general population. Although its predictive value for major depressive disorder (MDD) has been well documented, little is known about its role in the appearance of a first episode or in the recurrence. In this study, we examine the predictive value of insomnia symptoms in the incidence and recurrence of MDD. Methods In this longitudinal study, 2 interview waves were conducted between 2002 and 2015. The initial interviews (wave 1 [W1]) were carried out with 12,218 individuals aged ≥18 years from the general population in 8 US states. At follow-up 3 years later (wave 2 [W2]), 10,931 of the initial participants agreed to be interviewed again. Data were analyzed for the individuals who participated in both interviews (N=10,931). A diagnosis of MDD was made according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria. Insomnia symptoms were defined according to DSM-5 criteria A, C, and D for insomnia disorder. Results The 12-month prevalence of MDD was 9.5% (95% CI, 9.0%-10.0%) and 12.1% (95% CI, 11.5%-12.7%) in W1 and W2, respectively. Over the course of the study, 2.6% of participants experienced recurrence of depression (95% CI, 2.3%-2.9%). After adjusting for age, gender, race, and body mass index, participant characteristics in W1 that predicted recurrent MDD in W2 included early morning awakenings (EMA) (relative risk [RR], 3.2; 95% CI, 2.3-4.4), being dissatisfied with one’s sleep (RR, 2.8; 95% CI, 2.1-3.7), nocturnal awakenings (RR, 2.4; 95% CI, 1.8-3.2), and difficulty initiating sleep (DIS) (RR, 2.0; 95% CI, 1.5-2.9). MDD incidence was predicted by DIS (RR, 3.8; 95% CI, 2.5-5.9), being dissatisfied with one’s sleep (RR, 2.1; 95% CI, 1,4-3.2), and EMA (RR, 2.0; 95% CI, 1.2-3,2) at W1. Conclusion Insomnia symptoms appear to play an important part in predicting both the development of a first depressive episode as well as the recurrence of depression. Support (if any) Data analysis study were funded by Takeda Pharmaceutical Company.