Left superior temporal sulcus morphometry mediates the impact of anxiety and depressive symptoms on sleep quality in healthy adults

Abstract

Anxiety and depressive symptoms may predispose individuals to sleep disturbance. Understanding how these emotional symptoms affect sleep quality, especially the underlying neural basis, could support the development of effective treatment. The aims of the present study were therefore to investigate potential changes in brain morphometry associated with poor sleep quality and whether this structure played a mediating role between the emotional symptoms and sleep quality. One hundred and forty-one healthy adults (69 women, mean age = 26.06 years, SD = 6.36 years) were recruited. A structural magnetic resonance imaging investigation was performed, and self-reported measures of anxiety, depressive symptoms and sleep quality were obtained for each participant. Whole-brain regression analysis revealed that worse sleep quality was associated with thinner cortex in left superior temporal sulcus (STS). Furthermore, the thickness of left STS mediated the association between the emotional symptoms and sleep quality. A subsequent commonality analysis showed that physiological component of the depressive symptoms had the greatest influence on sleep quality. In conclusion, thinner cortex in left STS may represent a neural substrate for the association between anxiety and depressive symptoms and poor sleep quality and may thus serve as a potential target for neuromodulatory treatment of sleep problems.

Keywords: anxiety; depressive symptoms; magnetic resonance imaging (MRI); sleep quality; superior temporal sulcus (STS).

Fig. 1.

Results of mediation analysis of the association between anxiety, sleep quality (PSQI) and sleep quality–linked brain region after controlling for age, sex and education level. The upper three panels show (A) the negative correlation between cortical thickness of left STS and sleep quality, (B) the positive correlation between sleep quality and anxiety score and (C) the negative correlation between cortical thickness of left STS and anxiety score revealed by the partial correlation analysis. The lower panel (D) shows the results of the mediation analysis with a path diagram showing the strength of the associations whereby anxiety affects sleep quality through the thickness of the left STS. All data are standardized partial residuals after controlling for age, sex and education level. The indirect effect (c–c′ or a × b) was significant (for detailed information, see Supplementary Table S1).

Fig. 2.

Results of mediation analysis of the association between results of SAS and SDS sub-scores, sleep quality (PSQI) and sleep quality–linked brain region, after controlling for age, sex and education level. The upper, middle and lower rows, respectively, refer to (A) the somatic component of the SAS, (B) the affective component of the SDS and (C) the physiologic component of the SDS, which all show negative correlation with cortical thickness of left STS as shown in the left panels. Path diagrams of the mediation analysis are shown in the corresponding right panels. All data are standardized partial residuals after controlling for age, sex and education level. All indirect effects (c–c′ or a × b) were significant.

Fig. 3.

Exploratory commonality analysis using sub-scores of the somatic component of SAS, affective component and physiologic component of SDS with sleep-related items excluded as predictors and PSQI as outcomes. The upper, middle and lower rows, respectively, refer to (A) the somatic component of the SAS, (B) the physiologic component of the SDS and (C) the affective component of the SDS, which all show negative correlation with cortical thickness of left STS as shown in the left panels. Path diagrams of the mediation analysis are shown in the corresponding right panels. All data are standardized partial residuals after controlling for age, sex and education level. All indirect effects (c–c′ or a × b) were significant.