Table 2.

Meta-analyses results on the effect of psychological interventions on negative symptoms

Study	Control group	Participants, n	Model	Effect size	95% CI		P	I2, %
					Lower	Upper
Cognitive–behavioural therapy
Jones, 201844	TAU	729	FE	MD = −3.35, SMD = −0.49a	−3.84	−2.85	<0.001	72.19
	TAU	1087	FE	MD = −1.43, SMD = −0.17a	−1.94	−0.93	<0.001	84.37
	TAU	1436	FE	MD = −1.47, SMD = −0.16a	−1.94	−0.99	<0.001	89.01
	TAU	231	RE	MD = −4.11, SMD = −0.08a	−10.4	2.17	0.20	95.08
Jones, 201845	OPT	581	FE	d = −0.06	−0.32	0.20	>0.05	11.24
	OPT	45	RE	d = −0.08	−0.67	0.50	>0.05	0.00
	OPT	68	FE	d = −0.12	−0.36	0.59	>0.05	100
Jauhar, 201449	AC	−	RE	g = −0.13	−0.25	−0.01	0.03	47.70
Lutgens, 201731	CBT vs AC	−	RE	SMD = −0.34	−0.55	−0.12	0.00	73.60
Polese, 201942	TAU	800	FE	SMD = 0.08c	−0.06	0.21	0.286	0.00
Riehle, 202035	TAU	278	RE	g = −0.24	−0.47	0.004	−	0.00
	CR	238	RE	g = 0.12	−0.14	0.37	0.36	0.00
Sarin, 201164	OPT	461	RE	g = −0.10	−0.28	0.09	0.31	24.00
	TAU	318	RE	g = −0.21	−0.43	0.01	0.07	0.00
Turner, 201443	OPT	−	RE	g = 0.04c	−0.09	0.16	>0.05	0.00
Velthorst, 201517	TAU	2312	RE	g = 0.09c	−0.03	0.214	0.13	62.70
	TAU		RE	g = 0.16c	−0.10	0.41	0.23	−
Wykes, 200863	TAU	1268	RE	d = 0.44c	0.17	0.70	<0.05	118.1
Music therapy
Jia, 202048	TAU	775	RE	SMD = −0.61	−0.80	−0.42	<0.001	38.0
Geretsegger, 201747	TAU	177	FE	SMD = −0.55	−0.87	−0.24	<0.001	−
Acceptance and mindfulness-based
Cramer, 201638	TAU	111	RE	g = −0.27	−0.72	0.17	0.23	14.00
Hodann-Caudevilla, 202065	AC	506	RE	g = 0.40c	0.29	0.51	<0.01	82.50
Jansen, 202039	AC	1268	RE	d = −0.24	−0.44	−0.03	0.02	23.00
Liu, 202167	TAU	460	RE	g = −0.53	−0.72	−0.35	<0.001	0.00
	TAU	460	RE	g = −0.59	−0.78	−0.41	<0.001	0.00
Tonarelli, 201666	TAU	67	FE	SMD = 0.65c	0.17	1.13	0.008	0.00
Group
Burlingame, 202037	AC	4156 (total)	RE	g = 0.27c	0.15	0.40	<0.00	57.00
Orfanos, 201541	TAU	893	RE	d = −0.37	−0.60	−0.14	<0.00	59.80
	AC	783	RE	d = −0.09	−0.36	0.19	0.54	68.50
Social skills
Kurtz, 200850	AC	363	FE	d = 0.40c	0.19	0.61	<0.05	−
Lutgens, 201731	AC	−	RE	SMD = −0.31	−0.45	−0.17	<0.05	−
Turner, 201443	AC	3295	RE	g = 0.27c	0.01	0.53	<0.05	53.80
Turner, 201851	AC	−	RE	g = 0.19c	0.04	0.34	<0.05	18.65
Cognitive remediation
Turner, 201443	OTP	−	RE	g = −0.14b	−0.39	0.06	>0.05	40.99
Cella, 201736	AC	2511	FE	g = −0.34	−0.42	−0.27	<0.01	−
	AC	2511	RE	g = −0.35	−0.44	−0.25	<0.01	28
Lejeune 202153	AC	2581	RE	g = 0.16c	0.04	0.29	0.012	42.88
Family-based
Ma, 202054	TAU	158	RE	MD = −4.35, SMD = −0.53a	−5.62	−3.08	<0.05	31
Rodolico, 202252	TAU	2313	RE	SMD = −0.36b	−0.51	−0.21	<0.01	65
Lutgens, 201731	AC	−	RE	SMD = −0.19	−0.70	0.34	>0.05	−
Integrated
De Mare, 201855	TAU	217	FE	MD = −2.47	−4.11	−0.83	<0.01	0

AC, any comparator; d = Cohen's d; FE, fixed effects; g = Hedges’ g; MD, mean difference; OPT, other psychological therapies; RE, random effects; SMD, standardised mean difference; TAU, treatment-as-usual.

^a.SMD calculated see Supplementary Appendix 4 for details.

^b.Review presented negative value as favouring control condition.

^c.Review presented positive value as favouring experimental condition.