Original ArticleReciprocal dynamics between self-rated sleep and symptoms of depression and anxiety in young adult women: a 14-day diary study
Introduction
Overwhelming evidence has shown that women are at greater risk for insomnia, depression, and anxiety compared with men [1], [2], [3], [4]. As evidence supports insomnia to be highly comorbid with depression and anxiety [1], [2] and that insomnia is etiologically tied to and persists following remission of depression and anxiety [2], [5], [6], [7], [8], it is critical to describe the manner in which sleep and affective symptoms relate to one another across time. In recent years, diary approaches have been used to provide more nuanced characterizations of the day-to-day mechanics between sleep and health indices [9], [10], [11], [12], while maximizing ecological validity. Though insomnia is endemic to depressed and anxious women,1 no study to date has used a diary approach to capture the manner in which poor sleep influences affective symptoms, which may, in turn, impact sleep the following night and so on. In addition, it is currently unclear if sleep problems are similarly related to depression and anxiety, or whether different sleep disturbances map onto depression and anxiety separately. Such information may offer insight into how co-occurring sleep and affective problems are developed and maintained.
Sleep complaints are common in the contexts of depression and anxiety [1], [13], [14]. Even so, it is unclear whether specific sleep issues differ between the two disorders, that is, if specificity exists between depression and anxiety in relation to sleep. Though difficulty falling asleep, insufficient sleep quantity, and overall poor subjective sleep quality (SQ) are common experiences among both depressed and anxious individuals, different sleep disturbances may be more likely to give rise to depression, whereas others may more commonly exacerbate anxiety. Given the high comorbidity rates between depression and anxiety [15], as well as the shared features between the two disorders resulting in overlapping items on measurement tools [16], [17], previous studies may have been at a methodological disadvantage to detect specificity between affective symptoms and sleep indices. Thus, using a transdiagnostic approach (assessing overlapping and unique dimensions of depression and anxiety) would allow for evaluating whether various sleep problems are differently related to depression and anxiety (eg, if short sleep is related to depression-specific symptoms, but unrelated to anxiety-specific symptoms), or if sleep complaints are similarly related to both disorders (eg, if overlapping features of depression and anxiety are associated with prolonged sleep latency).
Clark and Watson’s tripartite model of anxiety and depression [16], [17], [18] offers that the two disorders have common, overlapping features, as well as characteristics that make each disorder unique from the other (Fig. 1). General distress represents the shared features of depression and anxiety, including fear, sadness, low self-esteem, and feelings of being “keyed up” or “on edge.” Though fear and sadness may typically be associated with anxiety and depression, respectively, the general distress symptoms do not distinguish between the two disorders and give rise to high comorbidity rates. Specific to anxiety is anxious arousal, characterized by physiological hyperarousal symptoms, such as psychomotor agitation, muscle tension, and shortness of breath. Unique to depression is anhedonia, characterized by blunted positive affective, and diminished capacity for enjoyment and appetitive drive. As much of the research on comorbidity among depression, anxiety, and insomnia is based on studies using depression and anxiety measures focused on general distress and other correlated symptoms (eg, change in appetite or sexual functioning), disorder-specific symptoms and their relationships with these various aspects of nightly sleep have been overlooked. To best characterize the reciprocal dynamics between sleep disturbances and these affective symptoms, it is critical to describe these associations longitudinally, thus offering insight into etiological processes fueling comorbid clinical states.
Although poor sleep has been historically viewed as a symptom of psychiatric illness, a growing body of literature has revealed greater complexity of the directionality between sleep disturbance and affective disorders. Mounting evidence supports that sleep disturbance and insomnia often precede the onset of depressive disorders [2], [5], [6], [7], [8], [19], whereas other studies have demonstrated anxiety [2], [8], [14] and depression [14], [20] as risk factors for insomnia development. Moreover, the onset of insomnia is at times concurrent with that of anxiety and depression [2]. Taken together, pathological mood and sleep are closely related, and difficulties in one area can lead to problems in the other. Even so, much of this information is gleaned from macrolevel prospective studies and retrospective accounts. Though helpful and informative, these approaches do not offer insight into the comparatively microlevel, for example, day to day, relationships among depression, anxiety, and poor sleep. Thus, using a daily diary design to characterize the manner in which sleep disturbance the present night influences symptoms of depression and anxiety the next day, and how these affective symptoms during the wake period impact sleep the following night, would improve our understanding of how disordered states of sleep and mood are codeveloped and maintained over time. Importantly, by using a transdiagnostic approach, we can begin to tease apart the shared and unique associations between insomnia and depression and anxiety.
To address this gap in the literature and improve our understanding of the interplay between sleep and mental illness in women, the present study used a 14-day diary approach to characterize the manner in which daily experiences of general distress (shared symptoms of depression and anxiety), anxious arousal (anxiety-specific symptoms), and anhedonia (depression-specific symptoms) were associated with self-reported sleep-onset latency (SOL), total sleep time (TST), and SQ. Repeated daily assessments allowed for examining the relationships between sleep and affective symptoms in both directions. Broadly, we predicted cyclical relationships between affective symptoms and subjective sleep disturbance parameters such that both greater depression and anxiety would predict longer SOL, shorter sleep duration, and poorer SQ, which, in turn, would lead to greater depression and anxiety the following day. Investigation of specificity between sleep parameters and affective symptoms was largely exploratory.
Section snippets
Participants
The present study was part of a larger project on the topic of women’s mental health. One hundred and seventy-one female college students were recruited from psychology courses at a large Midwestern university and received course credit for their participation. Inclusion criteria were reliable Internet access and being free of antidepressants for at least the four weeks before and during participation. The local Institutional Review Board approved this study. All individuals provided written
Sample characteristics
The sample consists of young female adults (age: 20.07 ± 3.32 years) who were largely identified as Caucasian (81.5%), though some ethnic diversity was observed (13.3% African–American, 1.2% Latino or Hispanic, 2.3% Eastern Asian or Pacific Islander, and 1.8% “Other”). Participants reported an average TST of 7 h and 22 min (±52 min) with an average SOL of 21 min (±14 min). Overall, SQ was rated as “Fairly Good” (3.09 ± .37). Regarding baseline mood symptoms, 32.2% of the sample scored in the at
Discussion
Using a 14-day diary design, the present study characterized the correspondence of day-to-day changes in depression and anxiety symptoms to nightly variations in SOL, sleep duration, and SQ in a sample of young adult women. Results showed the relationships between sleep disturbance and affective symptoms to be reciprocal in nature (Fig. 2). Broadly, experiencing poor sleep, increased depression and anxiety symptoms during the day, which, in turn, presaged greater sleep difficulties the
Conflict of interest
The authors have declared no financial conflicts of interest.
The ICMJE Uniform Disclosure Form for Potential Conflicts of Interest associated with this article can be viewed by clicking on the following link: http://dx.doi.org/10.1016/j.sleep.2016.03.014.
References (35)
- et al.
Place of chronic insomnia in the course of depressive and anxiety disorders
J Psychiatr Res
(2003) - et al.
Insomnia as a predictor of depression: a meta-analytic evaluation of longitudinal epidemiological studies
J Affect Disord
(2011) - et al.
Primary insomnia: a risk factor to develop depression?
J Affect Disord
(2003) - et al.
Self-reported sleep disturbance as a prodromal symptom in recurrent depression
J Affect Disord
(1997) - et al.
The association of insomnia with anxiety disorders and depression: exploration of the direction of risk
J Psychiatr Res
(2006) - et al.
The impact of sleep on female sexual response and behavior: a pilot study
J Sex Med
(2015) - et al.
A seven day actigraphy-based study of rumination and sleep disturbance among young adults with depressive symptoms
J Psychosom Res
(2014) - et al.
Depression and anxiety complaints; relations with sleep disturbances
Eur Psychiatry
(2005) - et al.
A bidirectional relationship between anxiety and depression, and insomnia? A prospective study in the general population
J Psychosom Res
(2008) - et al.
The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research
Psychiatry Res
(1989)