Evaluation of Autonomic Nervous System, Saliva Cortisol Levels, and Cognitive Function in Major Depressive Disorder Patients

Table 4

Results of photoplethysmography.

Domains	Control group	MDD group	value
	Mean ± SEM	Mean ± SEM
Mean PP (mmHg)	33.31 ± 1.40	48.92 ± 0.78	<0.0001
SDPP (mmHg)	2.40 ± 0.41	8.31 ± 0.88	<0.0001

Note. Photoplethysmography showed mean PP and SDPP were significantly higher in MDD participants than control; high significant difference between the control and MDD group ; PPG: photoplethysmography; mean PP: mean of pulse pressure; SDPP: standard deviation of pulse pressure; mmHg: millimeters of mercury.