Table 3.

Spearman rho correlation analyses between depression severity (as rated by the Patient Health Questionnaire-9, PHQ-9) and the positive emotion features expressed in status updates on Facebook (n=29) and Twitter (n=49). Twitter correlations are shown below the diagonal; Facebook correlations are shown above the diagonal. CIs are reported at 95% and shown in brackets.

Variable		1	2	3	4
1. PHQ-9a		−	.04 (−0.33 to 0.40)	.17 (−0.21 to 0.51)	−.04 −0.40 to 0.33
2. Average proportion		.02 (−0.26 to 0.30)	−	.79b (0.60 to 0.90)	.48c (0.14 to 0.72)
3. Variability (iSDd)		−.09 (−0.36 to 0.20)	.49b (0.24 to 0.68)	−	.61b (0.31 to 0.80)
4. Instability (time-adjusted MSSDe)		−.20 (−0.46 to 0.09)	.31c (0.03 to 0.54)	.48b (0.23 to 0.67)	−

^aPHQ-9: Patient Health Questionnaire-9.

^bP<.001.

^cP<.05.

^diSD refers to within-person variability.

^eMSSD: mean squared successive difference.