Table 6.

Effect maintenance in the Master Your Mood group (n = 121).

Instrument	Baseline (t 0) Mean (SD)	12 weeks (t 1) Mean (SD)	24 weeks (t 2) Mean (SD)	t 0 − t 1			t 0 − t 2			t 1 − t 2
				t a	P value	d b	t	P value	d	t	P value	d
Depression (CES-D)c	32.5 (8.4)	19.3 (9.7)	18.3 (10.7)	13.3	<.001	1.57	9.4	<.001	1.69	1.0	.31	0.10
Anxiety (HADS)d	11.2 (3.6)	8.0 (3.9)	7.8 (3.8)	12.8	<.001	0.89	10.0	<.001	0.96	0.8	.42	0.06
Masterye	12.8 (3.4)	15.9 (4.1)	16.7 (4.1)	9.2	<.001	0.91	10.4	<.001	1.14	2.8	.006	0.19

^a df = 120.

^b Individual standardized effect sizes [d = (t 0 − t 1) /SDt0); d = (t 0 – t 2) /SDt0 ; d = (t 1 – t 2) /SDt1] with positive effect sizes indicating improvement.

^c Dutch version of the Center for Epidemiologic Studies Depression Scale [43].

^d Dutch version of the Hospital Anxiety and Depression Scale [47].

^e 5-item Mastery Scale [48]. Higher scores stand for higher sense of mastery; differences calculated as t 1 − t 0 , t 2 − t 0 , t 2 − t 1.