1. Excessive Daytime Sleepiness & Depression
Lauren Feder & Sarah Bourne

2. A Quick Recap Research Question Hypothesis
Is excessive daytime sleepiness a significant contributing factor in depression in female graduate students?
Hypothesis
We hypothesize that higher levels of excessive daytime sleepiness will lead to higher incident cases of depression in female graduate students.
Exposed (EDS)
Compare Outcomes between Groups
Unexposed (No EDS)
Follow over time
Measure Incident Depression
6 Months
12 Months
18 Months
24 Months
Initial Sample Cohort
(n= 552)

3. Data Collection Methods Collection Time Points Main Exposure Variable
Validated questionnaires (ESS & CESD-R) given during interviews
Collection Time Points
Initial exposure & outcome data will be collected at the beginning of the study, then at 6 months intervals
i.e. Collect at baseline, 6 mos, 12 mos, 18 mos, & 24 mos
Main Exposure Variable
Epworth Sleepiness Scale & self-reported number of hours of sleep per week
Main Outcome Variable
Centers for Epidemiologic Studies Depression Scale Revised
Anyone found to have depression will be referred to their schools’ health clinic and/or counseling services for further treatment

4. Data Analysis
For our main exposure, the final variable will be dichotomous
EDS – Yes or No
For our main outcome, the final variable will be dichotomous
Depression – Yes or No
The measure of association we will calculate is the risk ratio
With an overall sample size of 552, we would be able to detect a risk ratio of 1.8 with 80% power
Source population: MUSC, CofC, & CSU
Covariates will include age, SES, marital status, current medications, caffeine intake, and alcohol and/or illicit drug use

5. Limitations
Lack of generalizability outside of female graduate students
Time and expense of a prospective cohort study
Length of time between measuring for incident cases of depression
Possible recall and response biases
Length of study limited by typical length of graduate programs (~2 yrs.)

6. References
Fernandez-Mendoza J, Calhoun SL. Excessive daytime sleepiness: Age, sleep, mood, and metabolic modulation. In: Modulation of sleep by obesity, diabetes, age, and diet. College of Medicine, Pennsylvania State University, Hershey, PA, USA: Elsevier Inc.; 2015: /B
Hein M, Lanquart J, Loas G, Hubain P, Linkowski P. Prevalence and risk factors of excessive daytime sleepiness in major depression: A study with 703 individuals referred for polysomnography. Journal of Affective Disorders. 2019; 243: doi: /j.jad
Sausser L. New report shows major depression ‘surged,’ especially among adolescents and millennials. The Post and Courier. May 10, Available from: Accessed October 18, 2018.
National Institute of Mental Health. Depression. National Institute of Mental Health Website. Updated Accessed October 18, 2018.
Brody DJ, Pratt LA, Hughes JP. Prevalence of depression among adults aged 20 and over: United States, NCHS Data Brief. 2018(303):1.
Johns MW. A new method for measuring daytime sleepiness: The Epworth sleepiness scale. Sleep. 1991;14(6):
Eaton WW, Muntaner C, Smith C, Tien A, Ybarra M. The center for epidemiologic studies depression scale revised. Center for Innovative Public Health Research Web site. Updated Accessed October 18, 2018.