Introduction: Depression is pervasive throughout the world and is often associated with sleep disorders (SDs). Both disorders compromise cognition, emotional well-being, and general health. The extent of these relationships has not been clearly ascertained because of significant rates of under or inadequate diagnoses along with a multitude of intervening variables associated with disease symptomatology. Investigations are further constrained by difficulty in acquiring valid data from people whose diagnoses have included complete nocturnal polysomnography (NP) and multiple sleep latency tests (MSLT).

Method: We constructed an 111-item questionnaire to use in conjunction with NPS, MSLT, the Epworth Sleepiness Scale (ESS), and medical chart reviews of people referred for evaluation of SDs.

Results: We analyzed data from 620 people diagnosed with SDs (280 female, 340 males). Of these, 353 had a history of depression. Analyses of the depression versus no depression groups revealed numerous differences. For example, people with depression had higher rates of BMI, ESS total, time to fall asleep, stage 1 sleep, and spent less time in REM. The depression group was also more likely to have: choking sensations, breathing with mouth open, arm/leg jerks, sleep talking, difficulty waking, grinding teeth, nightmares, screaming awakenings, bizarre dreams, awakening feeling paralyzed, difficulty concentrating, memory problems, stress, anxiety, irritability, headaches, ADD/ADHD, diabetes, and to be diagnosed with abnormal sleep architecture and primary snoring.

Discussion: SD’s and depression are associated with prolific health problems. We hope identification of the complex relationship shared by these disorders will contribute to facilitating prevention, early diagnosis, and effective treatment modalities.