Sleep quality modulates emotions in anxiety and depressive disorders
A recent study by researchers from the University of Illinois at Chicago, US, shows that patients with social anxiety disorder (SAD), generalized anxiety disorder (GAD) and/or major depressive disorder (MDD) experience problematic sleep and dysregulated cognitive appraisal.
The study included 78 patients (mean age, 26.3 years) diagnosed with SAD, GAD or MDD. Fifty-eight patients (74 percent) with SAD (48.7 percent), GAD (26.9 percent) or MDD (24.4 percent) had problematic sleep expressed subjectively as a Pittsburgh Sleep Quality Index (PSQI) global score >5. [Depress Anxiety 2017, doi: 10.1002/da.22622]
Evaluation of association between PSQI and symptom severity revealed that the PSQI global score positively correlated with the Hamilton Depression Rating Scale (HAM-D) (r=0.44; p<0.001) and Hamilton Anxiety Rating Scale (HAM-A) (r=0.39; p<0.001).
The PSQI score is a 19-item questionnaire that assesses sleep subjectively, with higher scores indicating worse sleep.
In the study, a wrist-worn accelerometer to measure objective sleep quality via actigraphy was worn by patients for an average of 6 consecutive days and nights. Findings were consistent with insomnia, which is associated with sleep efficiency <85 percent, duration <6.5 hours, and/or wake after sleep onset (WASO) >30 minutes.
Also with actigraphy, HAM-D scores were negatively associated with sleep efficiency (r=-0.26; p<0.02), and positively correlated with WASO (r=0.25; p<0.03).
“The PSQI global score positively correlated with depression and anxiety, whereas for actigraphy, depressive symptoms negatively correlated with sleep efficiency and positively correlated with WASO. It is reasonable to expect that differences between the PSQI global score and actigraphy indices of sleep would occur at the neural level. Moreover, PSQI more closely relates to the psychological component of sleep symptoms,” the authors explained.
Affective ratings for Reappraise, Maintain and Look of the functional MRI (fMRI) emotion regulation task (ERT) showed a significant result [F(2,154)=200.24; p <0.001].
Subjective fMRI ERT results, combined with PSQI and sleep efficiency measured by actigraphy, showed negative association with dorsal anterior cingulate cortex (DACC) activation (p<0.01).
“The DACC is part of a network encompassing cognitive, motor, execution and related functional systems. Anxiety and depression are characterized by sleep and emotion dysregulation. Worse sleep, expressed as high PSQI scores, was linked with less appraise-related frontal activation [ie, negative DACC activity correlation],” the authors said.
“The negative relationship with sleep efficiency and DACC activity was not expected. However, reappraisal would probably be an effortful task requiring high DACC recruitment,” they added.
“Further study is necessary to understand interactions between subjective and objective sleep measures and DACC activity during emotion regulation,” the authors commented.
“Our research indicates that sleep might play an important role in the ability to regulate negative emotions in people suffering from anxiety or depression,” they concluded.