Social interaction moderates the relationship between depressive mood and heart rate variability: evidence from an ambulatory monitoring study.

OBJECTIVE: There is considerable evidence that depressive mood is related to lower parasympathetic control of the heart, thus increasing cardiovascular risk. However, little is known about social factors (e.g., social affiliation) that might moderate this relationship.
DESIGN: The authors examined whether cardiac autonomic control in healthy individuals with depressive symptoms could be altered by social interaction. Therefore, the authors conducted a 22-hr ambulatory monitoring study with a sample of 63 adults. MAIN OUTCOME MEASURES: Depression was assessed by questionnaire. Heart rate, heart rate variability (HRV), physical activity, and negative affect were recorded throughout one day via portable monitoring devices. RESULTS AND
CONCLUSION: Multilevel analyses revealed that depression was related to elevated negative affect and higher heart rate throughout the day. Moreover, there was a tendency toward lower HRV in individuals with higher depression scores. This association, however, was moderated by social context. When depressive participants were alone they evidenced lower HRV and higher negative affect, but not when they were engaged in social interactions with a partner, family members, or friends. These findings suggest that the relation between depression and cardiac autonomic control could be altered by social interaction, thus possibly buffering adverse health effects.