Early indicators of vulnerability to depression: The role of rumination and heart rate variability.

BACKGROUND

Despite the evidence of increased levels of rumination and reduced heart rate variability (HRV) in depression, whether these measures can be considered early indicators of vulnerability to depression has yet to be investigated. Therefore, the present study aimed to investigate both levels of rumination and resting HRV in individuals with familial risk for depression that is the most reliable risk factor for the disorder.

METHODS

Rumination and vagally-mediated HRV were assessed using the Ruminative Response Scale and a smartphone-based photoelectric volumetric pulse wave assay, respectively, in 25 individuals who had family history of depression (but did not report current depressive symptoms), 15 individuals who reported depressive symptoms (but had no family history of depression), and 25 controls (without depressive symptoms and family history of depression).

RESULTS

Individuals with depressive symptoms and those with a family history of depression were characterized by higher levels of rumination and lower cardiac vagal control than controls.

LIMITATIONS

Given the small sample size, this study should be used to design larger confirmatory studies; the cross-sectional nature of the study does not allow discussing the results in terms of cause-effect relationships.

CONCLUSIONS

Our findings suggested that individuals at risk of developing depression, also in absence of depressive symptoms, are defined by defective self-regulation capacity that may lead to future depression episodes. Increased ruminative thoughts and reduced HRV may represent early indicators of vulnerability to depression. Effective prevention programs designed to reduce rumination and/or increase HRV may reduce the risk of developing a full-blown depressive episode.