Implicit cognition tests for the prediction of suicide risk of non-suicidal self-injury in individuals: A systematic review

Table 1 Characteristics of included studies

Ref.	Country	Aims of study	Sample	Age, mean ± SD	Gender distribution (female)	Test
Nock and Banaji[40], 2007	United States	Assessment of self-injurious thoughts using a behavioral test	n = 92: n (without NSSI) = 36; n (recent NSSI) = 53	17.10 ± 1.92	76.40%	SI-IAT
Brausch et al[26], 2022	United States	Examining NSSI features as motivational moderators in the relationship between hopelessness and suicide ideation	n = 420 (history of NSSI)	18.92 ± 1.38	80%	SI-IAT
Nagy et al[29], 2021	United States	An experimental investigation of the effects of self-criticism and self-compassion on implicit associations with NSSI	n = 233: n (with NSSI) = 76; n (without NSSI) = 161	19.37 ± 2.12	74.2%	SI-IAT
Powers et al[41], 2021	United States	Explicit and implicit measurement of NSSI in the prediction of concurrent and prospective self-injury	n = 421 (time 1); n = 324 (time 2)	18.92 ± 1.38 (time 1), 18.98 ± 1.38 (time 2)	82.7% (time 1), 82.1% (time 2)	SI-IAT
Glenn et al[32], 2016	United States	Implicit cognition about self-injury predicts actual self-injurious behavior: Results from a longitudinal study of adolescents	n = 662: With NSSI (n = 302), without NSSI (n = 360)	13.14 ± 0.7	57.7%	SI-IAT
Millner et al[21], 2018	United States	Implicit cognition as a behavioral marker of suicide attempts in adolescents	n = 71	14.8 ± 1.5	71.5%	D-IAT, S-IAT, SI-IAT
Glenn et al[27], 2017	United States	Implicit identification with death predicts change in suicide ideation during psychiatric treatment in adolescents	n = 276: With NSSI (n = 224), without NSSI (n = 52)	15.53 ± 1.34	71.0%	SI-IAT
Dickstein et al[34], 2015	United States	Self-injurious implicit attitudes among adolescent suicide attempters vs those engaged in NSSI	n = 136: With SI (n = 47), with NSSI (n = 46), controls (n = 43)	With SI: 15.85 ± 1.27; with NSSI: 15.24 ± 1.26; controls: 15.47 ± 1.29	With SI: 66.0%; NSSI: 84.5%; controls: 60.5%	SI-IAT
Cha et al[19], 2016	United States	Using implicit and explicit measures to predict non-suicidal self-injury among adolescent inpatients	n = 123: NSSI (n = 68), without NSSI (n = 55)	14.8 ± 1.5	71.5%	SI-IAT

NSSI: Non-suicidal self-injury; SI-IAT: Self-Injury Implicit Association Tests; D-IAT: Death Implicit Association Tests; S-IAT: Suicide Implicit Association Tests.

Table 2 Main findings regarding validity of implicit cognition test

Ref.	Test	Outcome	Timeframe	Main findings (with effect sizes and 95%CIs)
Nock and Banaji[40], 2007	SI-IAT	NSSI	Lifetime	Scores on the two versions were correlated (r = 0.50, n = 89, P < 0.001), and when entered simulate in the third step of the regression equation, the identity version continued to significantly predict self-injury (OR = 11.32, P = 0.02), whereas the attitude form of the test did not (OR = 2.87, P = 0.31)
Brausch et al[4], 2020	SI-IAT	SI	Lifetime	SI-IAT associated with suicide ideation (OR = 1.87, 95%CI: 1.23-2.85, P = 0.004)
Nagy et al[29], 2021	SI-IAT	NSSI	12 months	SI-IAT scores associated with NSSI history at both time points (P = 0.002) but not with frequency/recency (P > 0.05)
Powers et al[41], 2021	SI-IAT	NSSI frequency	6 months	Baseline SI-IAT predicted baseline NSSI (r = 0.32, P < 0.001) but not 6-month NSSI (r = 0.09, P = 0.12)
Glenn et al[32], 2016	SI-IAT	NSSI frequency	12 months	Implicit NSSI identification predicted 12-month NSSI (HR = 2.13, 95%CI: 1.34-3.38, P = 0.001)
Millner et al[21], 2018	D-IAT, S-IAT, SI-IAT	NSSI, SI	14 days	IATs showed good reliability (α = 0.78-0.82) but no predictive effect on suicide attempts (P = 0.23)
Glenn et al[27], 2017	SI-IAT	SI	12 months	Implicit death identification predicted discharge suicide ideation (β = 0.31, P < 0.001)
Dickstein et al[34], 2015	SI-IAT	SI	6 months	NSSI group showed stronger “cutting self” associations (Cohen’s d = 0.58, 95%CI: 0.19-0.97, P < 0.001)
Cha et al[19], 2016	SI-IAT	NSSI frequency	3 months	Controlling for NSSI history and prospective risk factors, SI-IAT scores predicted patients’ subsequent cutting behavior during their hospital stay (OR = 8.19, 95%CI: 1.56-42.98, P < 0.05)

CI: Confidence interval; SI-IAT: Self-Injury Implicit Association Tests; NSSI: Non-suicidal self-injury; OR: Odds ratio; D-IAT: Death Implicit Association Tests; S-IAT: Suicide Implicit Association Tests; HR: Hazard ratio.