College students have long been considered a population particularly affected by sleep difficulties. Previous studies have confirmed individuals with sleep disturbances may be at risk for development of depression. This study provides evidence in support of the hypothesis that sleep and specific aspects of depression are related. 147 students completed a demographic questionnaire, the Beck Depression Inventory-II (BDI-II), and a modified version of the Pittsburgh Sleep Quality Index (PSQI). 115 of these students participated in a second phase of the study, completing the National Sleep Foundation's Sleep Diary for two weeks and a second BDI-II. Results showed 43.5% of the sample reported having experienced depression for more than two weeks at some point in their lifetime and approximately 38% consistently reported trouble going to sleep or remaining asleep. Gender differences in depression correlated with the BDI sleep variable; when this item was removed from analysis, no gender differences in depression remained. The study identifies specific symptoms of depression most strongly related to sleep disturbances.. The results of this study have important real-world implications for both prevention and treatment of depression in college students..
Using mixed populations and different methodologies, a small body of evidence has accumulated suggesting a correlation between sleep loss and mood states, particularly depression. Sleep difficulties are specifically associated with depression in both college students and older adult populations (Moo-Estrella, Perez-Benitez, Solis-Rodriguez, & Arankowsky-Sandoval, 2005; Riemann, Berger, & Voderholzer, 2001; Weisman, Greenwald, Nino-Murica, & Dement, 1997; Ford & Kamerow, 1989). The direction of this relationship is not clear but most evidence suggests sleep problems put an individual at risk for later development of depression. Gillin's (1998) review suggests sleep complaints may be prodromal symptoms of depression and anxiety; the strongest evidence pointing to a link between at least two weeks' insomnia and subsequent depression. Ford and Kamerow (1989) found individuals with a history of sleep disturbances were more likely to meet diagnostic criteria for depression, anxiety disorders, and substance abuse than participants without a history of sleep disturbance. In their sample, 17% with insomnia and 17.5% with hypersomnia at a first interview were found to meet criteria for depression or anxiety by the second interview one year later.
Disturbances of sleep are typical for most people with depression and belong to the core symptoms of the disorder (Riemann, Berger, & Voderholzer, 2001), thus some studies may find correlations that are confounded due to sleep problems being listed on depression questionnaires. We could find no previous studies addressing this methodological problem.
As with all correlational data, the possibility exists that additional factors may account for the association between sleep difficulty and depression. But which specific symptoms of depression are related to and perhaps exacerbated by sleep problems? There is very little published research reporting attempts to tease out these specific factors in depression and their relation to sleep difficulties.
An early study by Beck, Lester, and Albert (1973) administered the Beck Depression Inventory (BDI) to over 200 people who had attempted suicide and found suicidal wishes correlated more strongly with cognitive items such as pessimism and sense of failure than with somatic symptoms like sleeping and eating problems. However, one of our studies (Brooks, Garrison, LaLonde, Quinones, & Bathija, 2003) with a college population found hours of sleep negatively correlated with the BDI item regarding suicidal thoughts as well as feelings of worthlessness. Emotional and cognitive reactions to stress were also ssociated with a greater number of sleep disturbances. …