TABLE 1.

Descriptive statistics and correlation coefficients between t₁- and t₂-scores of all measures.

	COM_t1	COM_t2	ESC_t1	ESC_t2	CEI_t1	CEI_t2	BDI_t1	BDI_t2	Mean	SD	Range
COM_t1	(0.90) (0.88)	0.83	0.53	0.50	0.91	0.77	−0.42	−0.32	1.90	15.21	−36–36
COM_t2	0.80	(0.76) (0.77)	0.45	0.59	0.76	0.92	−0.43	−0.46	3.01	14.85	−35–36
ESC_t1	0.54	0.41	(0.89) (0.89)	0.73	0.82	0.63	−0.51	−0.39	0.02	11.33	−34–29
ESC_t2	0.51	0.57	0.72	(0.90) (0.90)	0.67	0.84	−0.50	−0.54	2.27	11.09	−33–28
CEI_t1	0.91	0.71	0.84	0.68	(0.91) (0.91)	0.81	−0.52	−0.40	1.92	23.29	−54–53
CEI_t2	0.76	0.91	0.61	0.85	0.79	(0.78) (0.81)	−0.51	−0.55	5.28	23.24	−66–62
BDI_t1	−0.36	−0.33	−0.41	−0.41	−0.43	−0.41	(0.89) (0.89)	0.68	27.05	10.75	9–58
BDI_t2	−‘0.34	−0.43	−0.37	−0.55	−0.39	−0.54	0.67	(0.94) (0.94)	13.91	11.84	0–55
Mean	2.22	2.80	−0.24	2.03	1.98	4.83	26.90	13.36	–	–	–
SD	14.08	14.14	11.30	11.50	22.47	22.98	10.36	11.52	–	–	–
Range	−36–35	−36–36	−32–30	−33–36	−68–59	−69–72	9–56	0–50	–	–	–

Analyses of the first (n₁ = 459) and second (n₂ = 468) sample.

Means, standard deviations, range of scores and Spearman’s Rank coefficients of the first sample are displayed above, of the second sample below the diagonal.

Internal consistencies (Cronbach’s alpha) are presented in the diagonal (upper line: first sample, lower line: second sample).

Bold-faced coefficients give the retest-reliabilities (interval on average 5 weeks).

BDI, depressive symptoms; COM, cognitive motivation; ESC, effortful self-control; CEI, cognitive effort investment; t₁, before treatment; t₂, after treatment.

For all coefficients p < 0.001 (Bonferroni-adjusted α = 0.0018).