Table 2.

Analysis of main effects using the mixed-model L repeated measures analysis

Component	N*	Estimated least squares mean change scores of the PHQ-9†								Estimated differences of change scores (95% CI)	Effect size for Baseline-Week eight change scores‡ (95% CI)	Effect size for differences of change scores and their p values‡ (95% CI)	P value
		Week 1	Week 2	Week 3	Week 4	Week 5	Week 6	Week 7	Week 8
SM
Presence	544	−0.79	−1.31	−1.50	−1.86	−1.70	−1.75	−1.79	−1.88	0.19 (−0.29 to 0.67)	−0.65 (−0.78 to -0.53)	0.05 (−0.07 to 0.16)	0.44
Absence	549	−1.08	−1.34	−1.41	−1.48	−1.51	−1.67	−1.86	−2.07		−0.78 (−0.92 to -0.65)
BA
Presence	552	−0.85	−1.33	−1.42	−1.64	−1.60	−1.79	−1.85	−2.06	−0.17 (−0.65 to 0.31)	−0.73 (−0.86 to -0.60)	−0.04 (−0.16 to 0.08)	0.50
Absence	541	−1.01	−1.31	−1.49	−1.70	−1.61	−1.63	−1.79	−1.90		−0.70 (−0.84 to -0.57)
CR
Presence	544	−0.94	−1.05	−1.40	−1.60	−1.40	−1.47	−1.83	−2.02	−0.08 (−0.56 to 0.40)	−0.75 (−0.89 to -0.62)	−0.02 (−0.14 to 0.10)	0.74
Absence	549	−0.93	−1.60	−1.52	−1.74	−1.82	−1.95	−1.82	−1.94		−0.68 (−0.81 to -0.56)
AT
Presence	547	−0.75	−1.31	−1.30	−1.56	−1.71	−1.61	−1.73	−1.85	0.25 (−0.23 to 0.73)	−0.67 (−0.80 to -0.54)	0.06 (−0.06 to 0.18)	0.31
Absence	546	−1.12	−1.34	−1.62	−1.78	−1.50	−1.81	−1.91	−2.10		−0.76 (−0.89 to -0.63)
PS
Presence	546	−0.80	−1.38	−1.48	−1.63	−1.63	−1.74	−1.86	−1.91	0.14 (−0.34 to 0.62)	−0.71 (−0.84 to -0.57)	0.03 (−0.08 to 0.15)	0.56
Absence	547	−1.07	−1.27	−1.44	−1.71	−1.58	−1.69	−1.79	−2.05		−0.72 (−0.86 to −0.60)

*In a factorial trial design, all 1093 participants included in the analysis were randomly assigned 1:1 to either presence or absence of each component.

†Minus value indicates depression reduction.

‡We calculated effect sizes (standardised mean differences) using the baseline SD for within-group change score and the week 8 SD for group differences.

AT, assertion training; BA, behavioural activation; CIDI, Composite International Diagnostic Interview; CR, cognitive restructuring; PHQ-9, Patient Health Questionnaire-9; PS, problem-solving; SM, self-monitoring