Abstract
OBJECTIVES: The rates of sleep related breathing disorders (SRBD) and treatment outcomes of depression were compared among insomnia patients who had stratified levels of hypnotic use during a 10-year follow-up (2001-2010). DESIGN: A nationwide population-based cohort study. SETTING: A nationally representative cohort of 1,000,000 enrollees. PARTICIPANTS: Data were collected from patients with major depressive disorder (MDD) and comorbid insomnia during January 2001 to December 2003 (study cohort N = 3,235). The mean dosage of hypnotics at baseline in the study cohort was calculated, and this information was used to categorize the cohort into three equal-sized groups based on levels of hypnotic dosage. MAIN OUTCOME MEASURES: Patient response to antidepressants during a period that extended from 1 year before to 1 year after the study (short-term outcome) and patient psychiatric and non-psychiatric visits and hospitalizations during follow-up (long-term outcome) were analyzed. RESULTS: High-dosage patients presented the highest rates of subsequent SRBD diagnosis (3.9%), compared to medium-dosage patients (2.2%) and low-dosage patients (2.0%) (P = 0.011). Significantly more patients in the high-dosage group were difficult to treat with antidepressants compared to the other 2 groups (8.7% vs. 4.1% vs. 3.0%, P < 0.001), and their long-term depression outcome was worse for most parameters. Logistic regression showed that high-dosage hypnotics predicted the development of SRBD later (OR 1.678 [CI, 1.051 to 2.680], P = 0.030). CONCLUSIONS: There is a reliable association between a history of high dosages of hypnotics, subsequent diagnosis of sleep related breathing disorder, and worse depression outcomes.