Association Between Insomnia Symptoms and Moderately Severe to Severe Depression in the US Adult Population Open Access

Szymanski, Keith (Summer 2018)

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Study Objective:  To evaluate whether each of the following International Classification of Sleep Disorders (ICSD) insomnia symptoms:  difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), or nonrestorative sleep (NRS) are predictive of moderately severe to severe depression [as determined by a PHQ-9 (Physician Health Questionnaire-9) score of >15].

Methods:   Retrospective cross-sectional study was conducted which included survey respondents representative of the US adult population.  Respondents with a PHQ-9 score were stratified into two groups:  PHQ-9 score < 4 (no or minimal depression) [NMD], PHQ-9 score > 15 (moderately severe to severe depression) [MSS].  Multivariate logistic regression was utilized to determine which specific insomnia symptoms were predictive of depression severity.

Results:  2,431 adults completed the survey.  The overall response rate was 80.4%.  51.6% of respondents were in the NMD group and 16.2% of respondents were in the MSS group. Individuals in the MSS group reported more insomnia symptoms (DIS, DMS, NRS), when compared to the NMD group (47.32% vs. 4.90%, p < 0.05), 53.93% vs. 9.53%, p < 0.05, 77.16% vs. 47.08%, p < 0.05, respectively).   DIS, DMS, and NRS were significantly associated with MSS (OR=5.20, 95% CI: 3.10-8.74, p < 0.05, OR=4.16, 95% CI: 2.66-6.52, p < 0.05, OR=1.89, 95% CI :1.37-2.61, respectively).

Conclusions:  All three insomnia symptoms were associated with depression severity.  Of particular interest is the high percent of individuals reporting nonrestorative sleep which can occur in the absence of other insomnia symptoms.  Increasing the awareness of all pertinent insomnia symptoms may aid clinicians in tailoring treatments plans to the specific needs of each patient.    

Table of Contents

Table of Contents

Introduction                                         1

Methods                                                2

            Participants                                3

            Variables and Measurement      3

            Analysis                                    4

Results                                                 5

Discussion                                          11

Conclusions                                        15

References                                           17

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