Table 2.

Overview of reviewed studies

Authors	Year	Sample size and study populations	Task	Results	Performance bias free
(A) Overview of subclinical OCD studies
Ashbaugh & Radomsky32	2007	152 HC	Repeated Checking Taska	↓ confidence high-checkers vs low-checkers	−
Ben Shachar et al.28	2013	47 HC; high and low OC tendencies	General Knowledge Task	== confidence high vs low OC tendencies	+
Coles, Radomsky & Horng33	2006	S1: 51 HC S2: 81 HC	Repeated Checking Taska	S1 & S2: ↓ confidence with repeated checking	+
Cuttler et al.38	2013	199 HC	Prospective Memory Task	↓ confidence undermined group	+
Fowle & Boschen37	2011	60 HC	Repeated Cleaning Taska	no increase in confidence for repeatedly cleaned items, increase in confidence for non-repeatedly cleaned items	+
Hauser et al.29	2017	40 HC; high and low OC tendencies	Global Motion Detection Task	↓ metacognitive efficiency high compulsive group	++
Lazarov et al.26	2012	38 HC; high and low OC tendencies	False Feedback Muscle Tension Task	↓ confidence high compulsive group	+
Radomsky, Gilchrist & Dussault35	2006	55 HC	Repeated Checking Taska	↓ confidence with repeated checking	+
Radomsky & Alcolado34	2010	62 HC	Repeated Mental Checking Taska	↓ confidence with repeated checking	−
Rouault et al.30	2018	S1: 498 HC S2: 497 HC	Perceptual Decision-Making Task	S1: no relationship OCD symptoms and confidence S2: no relationship OCD symptoms and confidence or metacognitive efficiency AD symptom dimension ↓ confidence and ↑ metacognitive efficiency, CIT symptom dimension ↑ confidence and ↓ metacognitive efficiency	++
Van den Hout & Kindt31	2003a	S1: 39 HC S2: 40 HC	Repeated Checking Taska	S1 and S2: ↓ confidence with repeated checking	+
Van den Hout & Kindt36	2003b	40 HC	Repeated Checking Taska	↓ confidence with repeated checking	+
Zhang et al.27	2017	S1: 30 HC S2: 32 HC	False Feedback Muscle Tension Task	S1 and S2: ↓ confidence high compulsive group	+
(B) Overview of clinical OCD studies
Boschen & Vuksanovic53	2007	15 OCD, 40 HC	Repeated Checking Taska	↓ confidence OCD vs HC ↓ confidence with repeated checking	+
Bucarelli & Purdon47	2016	30 OCD, 18 anxious controls	Repeated Checking Taska	== confidence OCD vs anxious controls	−
Cougle, Salkovskis & Wahl40	2007	39 OCD checkers, 20 OCD non-checkers, 22 anxious controls, 69 HC	Memory Task	↓ confidence OCD vs HC and anxious controls	−
Dar et al.59	2000	20 OCD checkers, 29 PD, 23 HC	General Knowledge Task	↓ confidence OCD vs HC	+
Dar58	2004	S1: 20 OCD checkers, 20 PD, 20 HC S2: 15 OCD checkers, 15 HC S3: 6 OCD checkers, 6 HC	General Knowledge Task	S1, S2, and S3: ↓ confidence OCD vs both control groups S1, S2, and S3: ↓ confidence with repeated checking	+
Foa et al.41	1997	15 OCD, 15 HC	Memory Task	↓ confidence OCD vs HC	+
Hermans et al.57	2008	16 OCD, 16 clinical controls, 16 HC	Repeated Actions Taska	↓ confidence OCD vs both control groups	−
Karadag et al.42	2005	32 OCD, 31 HC	Memory Task	↓ confidence OCD vs HC	+
Lazarov et al.60	2014	20 OCD, 20 anxious controls, 20 HC	False Feedback Muscle Tension Task	↓ confidence OCD vs HC and anxious controls	+
Macdonald et al.43	1997	10 OCD checkers, 10 OCD non-checkers, 10 HC	Memory Task	↓ confidence OCD checkers vs non-checkers and HC	+
McNally & Kohlbeck39	1993	12 OCD checkers, 12 OCD non-checkers, 12 HC	Reality Monitoring Task	↓ confidence OCD vs HC	+
Moritz et al.48	2006	17 OCD checkers, 10 OCD non checkers, 51 HC	Source Memory Task	== confidence OCD vs HC	+
Moritz et al.54	2007	28 OCD, 28 HC	Memory Taska	↓ confidence OCD vs HC under high responsibility	+
Moritz et al.49	2009a	43 OCD, 46 HC	Memory Task	== confidence OCD vs HC	+
Moritz et al.51	2009b	32 OCD, 32 HC	Memory Task	== confidence OCD vs HC	+
Moritz et al.50	2011	30 OCD, 20 HC	Memory Task	== confidence OCD vs HC	+
Moritz & Jaeger44	2018	26 OCD, 21 HC	Memory Task	↓ confidence OCD vs HC	+
Radomsky, Rachman & Hammond55	2001	11 OCD	Repeated Checking Taska	↓ confidence under high responsibility	−
Tekcan, Topçuoglu & Kaya52	2007	25 OCD checkers, 16 OCD non-checkers, 27 HC	Memory Task	== confidence OCD vs HC	+
Tolin et al.56	2001	14 OCD, 14 anxious controls, 14 HC	Repeated Memory Taska	↓ confidence OCD vs both control groups with repetition	+
Tuna, Tekcan & Topçuoglu46	2005	17 OCD, 16 subclinical checkers, 15 HC	Memory Task	↓ confidence OCD vs HC	−
Vaghi et al.61	2017	24 OCD, 25 HC	Predictive Inference Task	== confidence OCD vs HC	−
Zitterl et al.45	2001	27 OCD, 27 HC	Memory Task	↓ confidence OCD vs HC	−
(C) Overview of subclinical schizophrenia studies
Koren et al.65	2017	61 help seeking adolescents	Verbal Memory, Executive – and Social Functioning Tasks	Positive relationship self-disturbance and meta-cognitive control	+
Laws & Bhatt70	2005	105 HC	Memory Task	↑ confidence in errors high delusion-proneness ↓ discrimination high delusion-proneness	−
Mckay, Langdon & Coltheart68	2006	58 HC	Reasoning Task	↑ confidence high delusion-proneness	−
Moritz et al.71	2014	2008 HC	Visual Perception Task	↑ confidence in errors high paranoia ↓ discrimination high paranoia	−
Moritz et al.73	2015	2321 HC	General Knowledge Taska	↑ confidence in errors high paranoia, exaggerated with high competence or easy questions ↓ discrimination high paranoia, exaggerated with high competence or easy questions	−
Rouault et al.30	2018	S1: 498 HC S2: 497 HC	Perceptual Decision-Making Task	S1: No relationship SCZ symptoms and confidence S2: No relationship SCZ symptoms and confidence or metacognitive efficiency AD symptom dimension ↓ confidence and ↑ metacognitive efficiency, CIT symptom dimension ↑ confidence and ↓ metacognitive efficiency	++
Scheyer et al.66	2014	78 help seeking adolescents	Verbal memory, executive functioning and social functioning tasks	= = confidence high vs low psychosis-prone groups	+
Warman69	2008	70 HC	Decision-making task	↑ confidence high delusion-proneness	−
(D) Overview of clinical schizophrenia studies
Bacon et al.95	2001	19 SCZ, 19 HC	General Knowledge Taskb	= = confidence SCZ vs HC ↓ FOK ratings SCZ vs HC	−
Bacon & Izaute96	2009	21 SCZ, 21 HC	Memory Taskb	↓ FOK ratings SCZ vs HC	−
Bhatt, Laws & McKenna74	2010	25 SCZ, 20 HC	False-Memory Task	↑ confidence in errors SCZ vs HC ↓ discrimination SCZ vs HC	−
Bruno et al.93	2012	28 SCZ, 14 HC	Emotional and Non-Emotional WCST	= = discrimination SCZ vs HC, but ↓ metacognitive performance SCZ vs HC	+
Davies et al.92	2018	41 FEP, 21 HC	Perceptual Decision-Making Task	↓ meta-d’ FEP vs HC	++
Eifler et al.75	2015	32 SCZ, 25 HC	False-memory Task	↑ confidence in errors SCZ vs HC ↓ discrimination SCZ vs HC	−
Eisenacher et al.86	2015	34 at risk patients, 21 FEP, 38 HC	Verbal Recognition Task	↑ confidence in errors at risk and FEP vs HC ↓ discrimination at risk and FPE vs HC	+
Gaweda, Moritz & Kokoszka76	2012	32 SCZ, 32 HC	Source-Monitoring Task	↑ confidence in errors SCZ vs HC ↓ discrimination SCZ vs HC	−
Gaweda et al.87	2018	36 at risk patients, 25 FEP, 33 HC	Source-Monitoring Task	↑ confidence in errors UHR and FEP vs HC ↓ discrimination UHR and FEP vs HC	−
Kircher et al.77	2007	27 SCZ, 19 HC	False-Memory Task	↑ confidence (more so in errors) SCZ vs HC	+
Köther et al.88	2012	76 SCZ, 30 HC	Emotion Recognition Task	↑ confidence in errors SCZ vs HC ↓ discrimination SCZ vs HC	−
Moritz & Woodward78	2002	23 SCZ, 15 HC	Source-Monitoring Task	↑ confidence in errors SCZ vs HC ↓ discrimination SCZ vs HC	−
Moritz, Woodward & Ruff79	2003	30 SCZ, 21 HC	Source-Monitoring Task	↑ confidence in errors SCZ vs HC ↓ discrimination SCZ vs HC	−
Moritz et al.80	2004	20 SCZ, 20 HC	False-Memory Task	↑ confidence in errors SCZ vs HC ↓ discrimination SCZ vs HC	−
Moritz et al.81	2005	30 SCZ, 15 HC	Source-Monitoring Task	↑ confidence in errors SCZ vs HC ↓ discrimination SCZ vs HC	−
Moritz & Woodward84	2006	31 SCZ, 48 psychiatric controls, 61 HC	Source-Monitoring Task	↑ confidence in errors SCZ vs both control groups ↓ discrimination SCZ vs both control groups	+
Moritz, Woodward & Rodriguez-Raecke82	2006	35 SCZ, 34 HC	False-Memory Task	↑ confidence in errors SCZ vs HC ↓ discrimination SCZ vs HC	−
Moritz, Woodward & Chen85	2006	30 FEP, 15 HC	Source-Monitoring Task	↑ confidence in errors FEP vs HC ↓ discrimination FEP vs HC	−
Moritz et al.83	2008	68 SCZ, 25 HC	False Visual Memory Task	↑ confidence in errors SCZ vs HC ↓ discrimination SCZ vs HC	−
Moritz et al.89	2012	23 SCZ, 29 HC	Emotion Perception Task	↑ confidence in errors SCZ vs HC ↓ discrimination SCZ vs HC	+
Moritz et al.91	2014	55 SCZ, 58 OCD, 45 HC	Perceptual Decision-Making Task	↑ confidence in errors SCZ vs HC ↓ discrimination SCZ vs HC	+
Peters et al.94	2007	23 SCZ, 20 HC	False-Memory Task	↑ confidence in errors HC vs SCZ ↓ discrimination SCZ vs HC	+
Peters et al.90	2013	27 SCZ, 24 HC	Emotional Memory Task	↑ confidence in errors SCZ vs HC ↓ discrimination SCZ vs HC	−
(E) Overview of subclinical addiction studies
Goodie100	2005	S1: 200 HC S2: 384 HC	General Knowledge Task	S1 & S2: ↑ overconfidence problem and possible pathological gamblers	−
Lakey, Goodie & Campbell101	2007	221 HC	General Knowledge Task & Iowa Gambling Task	↑ overconfidence problem and possible pathological gamblers	−
Rouault et al.30	2018	S2: 497 HC	Perceptual Decision-Making Task	S2: No relationship alcoholism symptoms and confidence or metacognitive efficiency AD symptom dimension ↓ confidence and ↑ metacognitive efficiency, CIT symptom dimension ↑ confidence and ↓ metacognitive efficiency	++
(F) Overview of clinical addiction studies
Brevers et al.102	2014	25 GD, 25 HC	Grammar Task	Disconnection confidence and accuracy GD	−
Le Berre et al.103	2010	28 AUD, 28 HC	Memory Taskb	↑ FOK judgments AUD vs HC	−
Mintzer & Stitzer105	2002	18 MMP, 21 HC	Memory Task	↑ confidence for errors MMP vs HC ↓ discrimination MMP vs HC	−
Moeller et al.104	2016	14 remitted CUD, 8 active CUD, 13 HC	Perceptual Decision-Making Task	↓ metacognitive efficiency active CUD vs remitted CUD and HC	++
Sadeghi et al.106	2017	23 MMP, 24 HC	Memory & Perceptual Task	↓ metacognitive efficiency MMP vs HC perceptual task, but not memory task	++
(G) Overview of subclinical depression/anxiety studies
Dunning & Story118	1991	S1: 164 HC S2: 259 HC	Future Prediction Task	S1 and S2: ↑ confidence depressed vs non-depressed	−
Quiles, Prouteau & Verdoux119	2015	50 HC	WCST, Digit Span, Memory Task and Emotion Recognition Task	No relationship confidence and depression/anxiety symptoms	−
Rouault et al.30	2018	S1: 498 HCS2: 497 HC	Perceptual Decision-Making Task	S1: Negative relationship confidence levels and depression/anxiety symptoms S2: Negative relationship confidence levels and anxiety symptoms, no relationship with metacognitive efficiency AD symptom dimension ↓ confidence and ↑ metacognitive efficiency. CIT symptom dimension ↑ confidence and ↓ metacognitive efficiency	++
Soderstrom, Davalos & Vásquez117	2011	97 HC	Memory Taskb	↓ calibration based on JOL mildly depressed vs HC = = calibration based on JOL moderate depressed vs HC	−
Stone, Dodrill & Johnson116	2001	200 HC	General Knowledge Task	↓ confidence depressed group	+
(H) Overview of clinical depression/anxiety studies
Bucarelli & Purdon47	2016	30 OCD, 18 ANX	Repeated Checking Task	== confidence ODC vs ANX	−
Dar et al.59	2000	20 OCD checkers, 29 PD, 23 HC	General Knowledge Task	== confidence PD vs OCD and HC	+
Fieker et al.123	2016	45 MDD, 30 HC	Emotional Perception Task	Negative correlation confidence and depression severity	+
Fu et al.121	2005	15 MDD, 15 recovered MDD patients, 22 HC	Memory, General Knowledge, Perceptual and Social Judgment Task	↓ confidence MDD vs HC == confidence recovered MDD vs HC and MDD	−
Hancock, Moffoot & O’Carroll120	1996	14 MDD, 14 recovered MDD patients, 14 HC	General Knowledge Task	↓ confidence for correct answers in MDD vs HC == confidence recovered MDD vs HC	+
Lazarov et al.60	2014	20 OCD, 20 ANX, 20 HC	False Feedback Muscle Tension Task	↓ confidence OCD vs ANX and HC	+
Szu-Ting Fu et al.122	2012	23 MDD, 22 dysphoria patients, 32 HC	Memory Task	↓ confidence MDD vs HC and dysphoria	−
Tolin et al.56	2001	14 OCD, 14 ANX, 14 HC	Memory Task	↓ confidence ANX vs HC	+

This table shows a summary of all studies assessing confidence in the different psychiatric disorders included in this review. In the various subparts, studies using the following populations are described: (A) subclinical OCD, (B) clinical OCD, (C) subclinical schizophrenia, (D) clinical schizophrenia, E) subclinical addiction, (F) clinical addiction, (G) subclinical depression/anxiety, and (H) clinical depression/anxiety. The results are schematically represented with ↓ signaling a significant decrease, ↑ significant increase and == no differences. Regarding the performance bias, the signs indicate the following: ++ : Study used bias free measures such as meta-d’ and/or actively kept performance equal between groups (e.g. by using a staircase procedure), +: The assessed groups had equal levels of performance, −: Study did not use bias free measures and did not control for performance differences between groups, or did not report accuracy measures. For more information about the most frequently used tasks, see Table 1

HC healthy controls, OC obsessive-compulsive, OCD obsessive-compulsive disorder, AD anxious-depressive, CIT compulsive behavior and intrusive thought, PD panic disorder, SCZ schizophrenia, FEP first-episode psychosis, FOK feeling of knowing, GD gambling disorder, AUD alcohol use disorder, MMP methadone maintenance patients, CUD cocaine use disorder, ANX anxiety disorder, MDD major depressive disorder, S1 study 1, S2 study 2

^aThis study has taken into account moderators (i.e. OCD-relevant contexts, responsibility level or subjective competence)

^bThis study used a prospective confidence measure