Table 2.

Results of linear mixed models.

	Estimate	t-Value	p-Value
A
Group	0.221	6.477	<0.001***
Age	−0.176	−2.908	0.007**
sin[2 × pi/24 × (t)]	−0.108	−24.935	<0.001***
cos[2 × pi/24 × (t)]	−0.087	−19.835	<0.001***
sin[2 × pi/12 × (t)]	−0.033	−7.638	<0.001***
cos[2 × pi/12 × (t)]	0.017	5.740	<0.001***
Group × sin[2 × pi/24 × (t)]	0.037	6.191	<0.001***
Group × cos[2 × pi/24 × (t)]	0.055	9.151	<0.001***
Group × sin[2 × pi/12 × (t)]	0.026	4.320	<0.001***
B
Group	−0.632	−5,981	<0.001***
Sex2	0.320	2,806	0.009**
sin[2 × pi/24 × (t)]	0.012	0.708	0.479
cos[2 × pi/24 × (t)]	−0.008	−0.464	0.642
sin[2 × pi/12 × (t)]	−0.025	−2,001	0.046*
Group × sin[2 × pi/24 × (t)]	−0.083	−3,403	<0.001***
Group × cos[2 × pi/24 × (t)]	−0.077	−3,125	0.002**

(A) Heart rate. Results are presented for significant terms of the linear mixed model predicting heart rate after log transformation, with random intercept. Sine and cosine terms are indicated for 24-h cycles and for 12-h cycles, respectively. Estimates for group and group × harmonic regression terms interactions are indicated for the depression group. (B) RMSSD. Results are presented for significant terms of the linear mixed model predicting RMSSD after log transformation, with random intercept. RMSSD, root mean square of successive differences. *P < 0.05; **P < 0.01; ***P < 0.001; ns, not significant. Bold values indicate significant results.