Cardiac Autonomic Balance Is Altered during the Acute Stress Response in Adolescent Major Depression—Effect of Sex

Figures

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  Figure 1. STROBE flow chart of the participants.

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  Figure 2. Time schedule of the study protocol.

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  Figure 3. The two-dimensional representation of the autonomic space (according to [10]). The • 0 intersection illustrates the mean position along parasympathetic and sympathetic dimensions. The reciprocity diagonal represents a dimension of reciprocally controlled autonomic divisions. Individuals in the reciprocal parasympathetic quadrant would have relatively high CAB scores, while individuals in the reciprocal sympathetic quadrant would have relatively low CAB scores. The coactivity diagonal represents the regulation dimension indexing the total autonomic activity. Individuals in the coactivation quadrant would have relatively high CAR scores, while individuals in the co-inhibition quadrant would have relatively low CAR scores. The location along the parasympathetic and sympathetic axes represents patterns of independent parasympathetic and sympathetic control. The individual quadrants represent • reciprocal parasympathetic, • reciprocal sympathetic, • co-activation and • co-inhibition modes.

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  Figure 4. (A–C) Distribution of cardiac beta-adrenergic sympathetic activity indexed by z score of left ventricular ejection time (−zLVET) and cardiac parasympathetic activity indexed by z score of spectral power in the high-frequency band of the heart rate variability (zHF-HRV) scores into autonomic space in MDD and control groups with respect to sex: (A) at rest; (B) during Go/NoGo task; (C) in recovery period (i.e., after Go/NoGo task). (D–F) Graphical representation of the parameters −zLVET and zHF-HRV (expressed as mean and SEM) into autonomic space across the MDD and control groups: (D) at rest; (E) during Go/NoGo task; (F) in recovery phase (i.e., after Go/NoGo task). MDD-total—full black circle, MDD-Boys—full blue squares, MDD-Girls—full red triangles, Controls-total—empty black circle, Controls-Boys—empty blue squares, and Controls-Girls—empty red triangles. MDD—major depressive disorder.

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  Figure 5. Cardiac autonomic balance (CAB) during complex stress protocol in MDD and control groups with respect to sex: 1—rest; 2—Go/NoGo task, 3—recovery period after Go/NoGo task; MDD-total—full black circle, MDD-Boys—full blue squares, MDD-Girls—full red triangles, Controls-total—empty black circle, Controls-Boys—empty blue squares, and Controls-Girls—empty red triangles; *** represents statistically significant differences in total MDD vs. total control group at level p < 0.001, ## represents statistically significant differences in MDD Boys group vs. control Boys group at level p < 0.01; ### represents statistically significant differences in MDD Boys group vs. control Boys group at level p < 0.001. MDD—major depressive disorder.

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  Figure 6. The correlation analysis of total CDI score and CAB in total group (i.e., MDD and control group together; black circles, black line), individually in boys group (blue squares, blue line) and individually in girls group (red triangles, red line); (A) at baseline, (B) during Go/NoGo task, (C) during recovery, (D) correlation analysis of total CDI score and CAR during recovery in total group (circles, black line) and individually in boys group (blue squares, blue line). CDI—Child’s Depression Inventory; CAB—cardiac autonomic balance; CAR—cardiac autonomic regulation.