Relationship between psychosomatic diagnoses and various autonomic indicators: which diagnoses have stronger...

Various diagnoses in psychosomatic medicine have been found to exhibit features of autonomic activity, primarily characterized by low parasympathetic activity. However, because depression, anxiety, and somatic symptoms often coexist, it remains to be clarified whether certain diagnoses are more strongly associated with autonomic activity than others. We also aim to explore whether the relationship between diagnosis and autonomic activity is through a top-down (from brain to autonomic nervous system) mechanism.

A total of 502 participants were included in this study. All participants underwent standardized diagnostic interviews. Seven indices about autonomic activity, including heart rate variability, skin conductance, and finger temperature, were collected in a resting state. We used multiple linear regression analyses to clarify the relationship between diagnoses and autonomic activity, adjusting for various diagnoses and demographic factors. We also examined whether quality of life (QOL) could serve as a mediator between the diagnoses and autonomic activity.

Major depressive disorder and obsessive-compulsive disorder were the diagnoses most significantly negatively associated with parasympathetic activity. Psychological factors affecting other medical conditions, adjustment disorder, and functional dyspepsia showed significant negative associations with sympathetic activity. Path analysis indicated that QOL could serve as a complete mediator between major depressive disorder and parasympathetic activity.

The results indicate that among the diagnoses commonly seen in psychosomatic medicine, the negative association between major depressive disorder and parasympathetic activity is relatively robust. Analyses incorporating QOL suggest that the relationship between depression and parasympathetic activity is more likely to operate through a top-down pathway.