Table 2.

Studies using fMRI and Reward Tasks.

Study Characteristics					Early Stress Exposure Characteristics			Reward Task Characteristics			Results in ELS Group
											Neural response findings				Other findings
Author, year	Study N (N exposed)	Gender	Mean Age	Diagnosis or symptoms	Nature of exposure	Timing of exposure	Method to assess exposure	Reward phase/type	Task	Object
											Striatum*	mPFC	Amygdala	Other Areas and Striatal Subregions
Baranger, 2016	665 (-)	Both	19.6	7.8% met DSM-IV criteria for Axis I disorder, including alcohol use disorder	Abuse and neglect	<17 years	CTQ	Delivery	Reward-guessing task	Monetary	↑ ventral striatal reactivity to reward-related stimuli, NS after controlling for confounders				PER1 rs3027172 genotype interacted with ELS to predict both problematic drinking.
Birn, 2017	42 (23)	Both	20.5	NR	“Severe negative life events and circum-stances”	< 11 years	YLSI	Anticipation and delivery	MID	Monetary				↓posterior cingulate, middle temporal gyrus, lingual gyrus, right middle frontal gyrus and cerebellum in anticipation, but not delivery of reward vs no-reward	On separate gambling task, high childhood stress correlated with decreased latency to place bets, the choice of low probability targets, and failure to adjust behavior to feedback.
Boecker, 2014	162 (-)	Both	24.4	Lifetime ADHD symptoms	Early family adversity (low educational level, overcrowd-ing, parental psychiatric disorder, etc.)	3 months	Parent interview	Anticipation and delivery	MID	Monetary or verbal feedback	↓ during anticipation ↑during delivery of verbal, but not monetary, reward			↓ putamen, pallidum, left thalamus, left insula, left ACC and right anterior hippocampus during anticipation; ↑ bilateral insula, right pallidum and bilateral putamen during delivery of verbal, but not monetary, reward	↑ reaction time. No effect on number of win trials. ↓ contingent negative variation on EEG.
Boecker-Schlier, 2016	168 (-)	Both	24.5	None meeting DSM criteria	Childhood family adversity (low educational level, overcrowd-ing, parental psychiatric disorder, etc.)	<11 years	Parent interview	Anticipation and delivery	MID	Monetary and verbal	↓left ventral striatum during anticipation, ↑right ventral striatum during delivery in COMT Met homozygotes			↓ACC and left medial frontal gyrus during anticipation, ↑ACC during delivery in COMT Met homozygotes	↓EEG contingent negative variation signal during anticipation. No significant effect of adversity on reaction time.
Casement, 2014	120 (-)	Female	16	2.5% major depression	Social stressors (low parental warmth, peer victimiza-tion)	11–12 years	PCRS and PES	Anticipation	Reward-guessing task	Monetary	↑ for low parental warm	↑ for low parental warm ↓ for higher peer victimization	↑ for low parental warm	= OFC	Stress-related neural response to potential rewards correlated with depressive symptoms.
Casement, 2015	157 (-)	Male	20	NR	Cumulative stressful life events	15–18 years	LEQ and IPSI	Anticipation and delivery	Reward-guessing task	Monetary		↓ for anticipation and delivery			↑ cumulative stressful life events associated with more problematic alcohol use. mPFC response mediated association between stressful life events and later symptoms of alcohol dependence.
Dennison, 2016	59 (21)	Both	17	14% of maltreated sample met criteria for MDD	Abuse and neglect	<17 years	CTQ and CECA	Response to positive and neutral stimuli	Viewing social images	Socio-affective cues	↑			↑left NAcc, and left putamen for positive relative to neutral stimuli	Higher levels of reward response in left putamen associated with decreased depression in maltreated youth.
Dillon, 2009	44 (13)	Both	24.6	77% of ELS group met DSM-IV criteria for an Axis I disorder at some time	Abuse	≤13 years	AAI, TSS, CTS and protective services records	Anticipation	MID	Monetary				↓ left globus pallidus	↑ symptoms of anhedonia and depression. Rated reward cues less positively. ↑ reaction time. ↑ putamen volumes.
Goff, 2013	69 (38)	Both	9.9	33% in ELS group with clinically significant externalizing/internalizing symptoms	Previously institutional-ized	< 2 years	-	Viewing happy faces	Emotional faces task	Socio-affective cues	↓			↓ NAcc	↑ depression. Atypical NAcc development. Ventral striatum activation to happy faces negatively correlated with depression scores in ELS individuals.
Hanson, 2015	106 (-)	Both	13.8	Free of all psychopath-ology, except for anxiety disorders, at baseline	Emotional neglect	< 15 years	CTQ	Delivery	Reward-guessing task	Monetary	↓ to positive feedback = to negative feedback				↓ in this reward-related ventral striatum activity associated with ↑ symptomatology and partially mediated association between emotional neglect and subsequent depression.
Hanson, 2016	72 (-)	Male	26.3	High risk for long-term antisocial behavior	Parental loss, medical problems, other major life stressors	<Grade 12	Life Changes measure	Delivery	Card-guessing task	Monetary	↓ response to reward ↓ response to positive feedback = for negative feedback				Effect significant for stress during early, but not later, childhood. No association between ventral striatum activity and adult internalizing or externalizing symptoms.
Holz, 2017	171(-)	Both	25	Conduct Disorder	Childhood family adversity (low educational level, overcrowd-ing, parental psychiatric disorder, etc.)	<11 years	Parent interview	Anticipation	MID	Monetary and verbal	↓ventral striatum and dorsal striatum during anticipation				Conduct disorder partially mediated effects of adversity on brain activity. Negative relationship between reward dependence and adversity.
Mehta, 2010	23 (12)	Both	16	“Quasi-autism,” hyper-activity, cognitive impairment, disinhibited attachment	Romanian adoptees – previously institutional-ized	< 2 years	-	Anticipation	MID	Monetary	↓		=	↓ Caudate nucleus = Insula and thalamus	Adoptees did not recruit striatum during reward anticipation despite comparable performance accuracy and latency. Accuracy on MID task did not differ.
Morgan, 2014	120 (-)	Male	20	13% MDD or dysthymia, 14% history of substance dependence, 8% history of ASPD	Low maternal warmth and maternal depression	< 2 years	Observation during mother–child interactions and SCID with mothers	Anticipation and delivery	Reward-guessing task	Monetary	↑ for anticipation	↑ for anticipation
Takiguchi, 2015	36 (16)	Both	12.6	RAD	Abuse and neglect	< 12 years	CATS		Gambling task	Monetary	↓			↓NAcc and caudate	Earlier age of stress better predictor of decreased activity. Negative correlations between bilateral striatal activity and avoidant attachment. ↓ reaction time.

Notes: AAI, Adult Attachment Interview; ACC, anterior cingulate cortex; ADHD, attention-deficit/hyperactivity disorder; ASPD, antisocial personality disorder; CATS, Child Abuse and Trauma Scale; CS, conditioned stimulus; COMT, catechol-o-methyltransferase; CTQ, Childhood Trauma Questionnaire; CTS, Conflict Tactics Scale; DSM, Diagnostic and Statistical Manual of Mental Disorders; ELS, early life stress; fMRI, functional magnetic resonance imaging; IPSI, Interpersonal Problem Situations Inventory for Urban Adolescents; LEQ, Life Event Questionnaire for Adolescents; MDD, major depressive disorder; met, methionine; MID, monetary incentive delay; mPFC, medial prefrontal cortex; NAcc, nucleus accumbens; NR, not reported; NS, not significant; PCRS, Parent-Child Rating Scale; PES, Peer Experiences Scale; RAD, reactive attachment disorder; SCID, Structured Clinical Interview for DSM; TSS, Traumatic Stress Schedule; YLSI, Youth Life Stress Interview.

^*, Neural response findings included under striatum whenever subregions or whole striatum was activated

↑, higher relative to non-exposed subjects

=, same as non-exposed subjects

↓, lower relative to non-exposed subjects