Table 2.

Childhood trauma and cognitive function in patients with established bipolar disorder, schizophrenia, psychosis and healthy participants.

Study	Participants (Patients/Healthy participants) N	Gender (Patients/Healthy participants) Male : Female	Age (Patients/Healthy participants) Mean/SD	Stress questionnaire	Cognitive domains and tests	Main findings – CT and cognitive performance
Patients with established bipolar disorder and healthy participants
Poletti et al., 2017	BD = 76 HP = 90	BD = 51 : 51 HP = 24 : 33	BD = 47.75 ± 11.58 HP = 29.60 ± 10.55	RFQ	•BACS for verbal memory, working memory, psychomotor speed and coordination, selective attention, semantic fluency, letter fluency •WCST for executive functions	•Significant effect of high levels of CT on poorer global cognitive ability across BD and HP groups •Significant effect of high levels of CT on poorer speed of processing in BD with opposite pattern in HP
Bucker et al., 2013	BP = 64 HP = 28	BP = 28 : 36 HP = 11 : 17	BP = 22.89 ± 4.36 HP = 22.78 ± 4.90	CTQ (28 – item version)	•NART and Kaufman Brief Intelligence Test for intellectual ability •TMT, Stroop Test and Color Naming Trials for processing speed and executive function •CVLT for attention and verbal memory •WMS-III for working memory •CANTAB for attention, working memory, executive function and nonverbal memory	•Poorer performance in memory for BP with CT in contrast to BP w/o CT •Poorer performance in memory for BP with CT in contrast to HP w/o CT •Significant negative correlation between greater number of CT events and poorer performance on memory in BP group •Significant negative associations between greater number of CT events and poorer performance on (i) executive functioning and (ii) memory in HP group
Marshall et al., 2016	BP = 233 HP = 90	BP w CT = 32 : 85 BP w/o CT = 42 : 74 HP w CT = 8 : 9 HP w/o CT = 28 : 45	BP w CT = 40.90 ± 11.40 BP w/o CT = 38.70 ± 13.10 HP w CT = 36.50 ± 14.20 HP w/o CT = 37.40 ± 14.10	CTQ (28 – item version)	•WASI for general cognitive ability •Go/No-Go Task for attention and inhibitory control	•Significant main effect of CT on executive function •Significantly negative correlation between present CT and reduced executive function in BP group
Patients with established schizophrenia and bipolar disorder
Aas et al., 2012b	SZ = 239 BP = 167	SZ + BP = 214 : 192	SZ + BP = 30.07 ± 3.00	CTQ (28 – item version)	•WASI for general cognitive function, perception, visuospatial abilities and verbal abilities •CVLT for verbal memory, verbal fluency and executive function •WMS-III for working memory	•Significant relationships between PA, sexual abuse, physical neglect and poorer performance on general cognitive ability and executive function in BP group •No significant relationships between emotional neglect and general cognitive ability, memory and executive function
Patients with psychosis and healthy participants
van Os et al., 2017	PSY = 1119 (SZ = 940) Siblings of PSYa = 1059 HP = 586	PSY = 850 : 269 Siblings of PSY1 = 487 : 572 HP = 270 : 316	PSY = 27.57 ± 7.95 Siblings of PSY1 = 27.83 ± 8.27 HP = 30.42 ± 10.58	CTQ (25-item version)	•Baseline: WAIS-III for general cognitive functioning •3 year follow-up: WAIS-III for general cognitive functioning •6 year follow-up: WAIS-III short-form for general cognitive functioning	•Negative association between higher scores of CT in HP and reduced general cognitive ability at 3 time points •No difference between groups for moderating effect of CT on time or general cognitive ability over 6 years
Patients with psychosis
Mansueto et al., 2017b	PSY = 532	PSY = 402 : 130	PSY = 27.61 (7.61)	CTQ (25-item version)	•WAIS-III for general cognitive ability •World Learning Task for verbal memory •CTQ for attention and vigilance •RST for reasoning and working memory	•PSY with CT performed worse on memory function than patients without CT.
Patients with established schizophrenia and healthy participants
Green et al., 2015	SZ = 617 HP = 659	SZ = 415 : 202 HP = 291 : 368	SZ = 39.65 ± 10.82 HP = 42.48 ± 13.58	CAQ (20-item version)	•WTAR for premorbid IQ •RBANS for immediate memory, delayed memory, attention, language, construction •WAIS for working memory •COWAT for executive functioning	•Significant main effect of childhood maltreatment and general cognitive ability for both SZ and HP groups separately.
Green et al., 2014	SZ = 617 HP = 659	SZ = 415 : 202 HP = 291 : 368	SZ = 39.65 ± 10.82 HP = 42.48 ± 13.58	CAQ (20-item version)	•WTAR for premorbid IQ •RBANS for attention and memory function •WAIS for executive function •COWAT for executive function	•Association between CT and cognitive performance not reported
McCabe et al., 2012	SZ = 408 HP = 267	SZ = 65.7 % male HP = 43.4 % male	SZ = 40.72 ± 11.07 HP = 39.27 ± 13.70	CAQ (20 item version)	•WTAR and WASI for general cognitive function	•Negative associations between number of CT events and general cognitive ability across SZ and HP groups •In HP group only: Negative associations between number of CT events and general cognitive ability
Patients with established schizophrenia
Ruby et al., 2017	SZ = 28	SZ = 20 : 8	SZ = 31.50 (9.70)	ETI	•WAIS-III for general cognitive ability •WMS-R for verbal and visual memory, attention and delayed recall •WCST for executive function •TMT for processing speed and visual attention •COWAT for verbal fluency	•No association between CT and cognitive function found
Li et al., 2017	SZ = 162	SZ = 58 : 104	SZ = 37.82 ± 10.16	CTQ (28 – item version)	•RBANS for immediate memory, visuospatial construction, language, attention and delayed memory	•Significant negative correlations between physical abuse, sexual abuse and CT with executive function. •Significant negative correlations between physical neglect with memory and executive function.
Kelly et al., 2016	SZ = 80	SZ = 56 : 24 Females with PA = 10 Females w/o PA = 14 Males with PA = 11 Males w/o PA = 45	Females with PA = 37.80 ± 10.80 Females w/o PA = 32.60 ± 11.90 Males with PA = 30.90 ± 7.70 Males w/o PA = 31.6 ± 9.80	CTQ (28-item version)	•RBANS for immediate memory, delayed memory, visuo-spatial construction, language and attention	•No significant differences for general cognitive ability and memory between the groups
Shannon et al., 2011	SZ = 85	SZ = 67 : 18	SZ = 41.10 ± 11.70	CTQ (28-item version)	•NART for premorbid IQ •WMS-III for verbal memory, working memory	•SZ with CT performed better on general cognitive ability than SZ w/o CT •SZ with CT performed worse on memory than SZ w/o CT •SZ with CT performed better on working memory than SZ w/o CT
Schenkel et al., 2005	SZ SZ = 40	SZ = 25 : 15 SZ with ACE = 10 : 8 SZ w/o ACE = 15 : 7	SZ = 41.90 ± 10.70	Medical charts and interview	•Shipley Institute of Living Scale Vocabulary Subtest for verbal intelligence •Hayling Sentence Completion Task for verbal processing speed and verbal inhibition •Brixton Spatial Anticipation Task for non-verbal problem-solving and sequencing skills •COWAT for verbal fluency •Contour Integration Test for visual context processing	•SZ with a history of abuse performed worse than SZ w/o a history of abuse on general cognitive ability •No significant correlations between history of abuse and executive function •In a factor analysis of hospitalizations, cognitive domains, childhood problems and clinical symptoms-childhood problems and greater clinical symptomatology with cognitive impairment were significant •Significant effect across groups for the association between reduced general cognitive ability with greater exposure to abuse
Lysaker et al., 2002	SZ = 36	SZ = 36 : 0	SZ = 46.00 ± 10.00	CAQ	•WAIS-III for premorbid intelligence and working memory	•No findings reported for relationships between trauma, general cognitive ability and executive function

Abbreviations: BACS, Brief Assessment of Cognition in Schizophrenia; BD, patients with bipolar disorder; CANTAB, Cambridge Neuropsychological Automated Test Battery; CATS, The Child Abuse and Trauma Scale, CAQ, Childhood Adversity Questionnaire; COWAT, Controlled Oral Word Association Test; CT, Childhood trauma; CTQ, Childhood Trauma Questionnaire; CVLT, California Verbal Learning Test; ETI, Early Trauma Inventory; HP, healthy participants; IQ, intelligence quotient; NART, National Adult Reading Test; PSY, patients with psychosis; RBANS, Repeated Battery for Assessment of Neuropsychological Status; RFQ, Risky Families Questionnaire; RST, Response Shifting Task; SD, Standard Deviation; SZ, Patients with schizophrenia; TMT, Trail Making Task; WASI, Wechsler Abbreviated Scale of Intelligence; WAIS-III, Wechsler Adult Intelligence Scale - III; WCST, Wisconsin Card Sorting Test; WSM-III, Wechsler Memory Scale; WTAR, Wechsler Test of Adult Reading.

^aNo psychiatric diagnosis.

^bOnly baseline data reported.