Table 2. Comparison between all depressed (MDD-only and MDD+PTSD) and healthy control (HC) subjects.

Parameters	Estimate (bias)	SEM	t	p	95% CI boot
					Lower Limit	Upper Limit
Early Discounting (β)
HC	0.664 (0.007)	0.147	4.939	< 0.001	0.4133	0.9922
MDD	1.540 (-0.049)	0.372	6.148	< 0.001	1.074	2.479
Group differences in early discounting (β* g)
HC vs. MDD	0.876 (0.048)	0.398	3.081	0.002	0.3018	1.7999
Late Discounting over gains (δ)
HC	-0.012 (0.001)	0.012	-1.155	0.249	-0.0338	0.0126
MDD	0.042 (0.001)	0.013	2.999	0.003	0.0165	0.0681
Late Discounting over losses (δ* l)
HC	-0.022 (-0.000)	0.014	-1.739	0.083	-0.0501	0.0044
MDD	-0.046 (-0.000)	0.016	-2.798	0.005	-0.0773	-0.0138
Group differences in late discounting over gains (δ* g)
HC vs. MDD	0.054 (-0.000)	0.018	3.088	0.002	0.0187	0.0883
Group differences in late discounting over losses (δ* g* l)
HC vs. MDD	-0.023 (0.000)	0.021	-1.123	0.262	-0.0648	0.0181

Results from the best fitting quasi-hyperbolic model and bootstrap analysis showing parameter estimates for each group and group differences in early and late discounting over gains and losses.

β: early discounting, δ: late discounting, g: effect of group on discounting slope, l: effect of loss on discounting slope. Parameter estimates are shown together with their estimated bias based on bootstrap analyses (in parentheses), respective standard errors (SEM), t statistic, p values, and 95% confidence intervals from confirmatory nonparametric bootstrap analyses.

Parameter estimates reflect quasi-hyperbolic intertemporal choice functions for each group (β, δ and, δ * l). Interactions with the group dummy (g) reflect differences in slopes between groups for delays smaller than one year (β* g), as well as delays greater than one year in the domain of gains (δ* g) and losses (δ* g * l).