Associations between parental conflict and social and monetary reward responsiveness in adolescents with clinical depression

Abstract

Increased rates of depression beginning in adolescence are thought to be attributed in part to marked developmental changes in reward systems and interpersonal relationships. Blunted reward response has been observed in depression and this may be shaped in part by social experiences, raising questions about the combined associations of parental conflict, depression, and reward response in both social and monetary domains. The present study used the reward positivity (RewP), an event-related potential that indexes both monetary and social reward processing, to examine the unique and combined associations of parental conflict and depressive symptoms on reward responsiveness in adolescents with clinical depression (N = 70) 14–18 years of age (M = 15.81, SD = 1.46; 65.7% female). Results indicated that depressive symptoms interacted with maternal conflict in characterizing the RewP to social, but not monetary, rewards. Specifically, higher levels of current depressive symptoms and potentiated maternal conflict together were associated with an attenuated RewP to social rewards in this clinical sample. We found no significant effects of paternal conflict. This investigation highlights maternal conflict as an important environmental factor for reward responsiveness and also emphasizes the utility of examining social reward responsiveness in depression in order to better understand the impacts of contextual factors.

The prevalence of depression increases dramatically in adolescence compared to childhood (Kessler et al., 2001), which is thought to be due in part to developmental changes in the reward system and increased motivation to obtain more abstract rewards such as social acceptance (Davey et al., 2008). Indeed, adolescence is characterized by tremendous social interest and change, such that interpersonal relationships are especially influential (Smetana et al., 2006). Reward system function reflects one component of positive valence systems, a domain of the Research Domain Criteria (RDoC), that appears to be a core process underlying depression and other forms of psychopathology (Insel et al., 2010; Klawohn et al., 2021; Kujawa et al., 2020; Proudfit et al., 2015). Moreover, although depression may be related to withdrawal from emotional stimuli in both the positive and negative valence system domains (Bylsma, 2021; Bylsma et al., 2008; Rottenberg & Hindash, 2015; Weinberg et al., 2016), blunted reward responsiveness, specifically, has been demonstrated to be a key component of depression (Kujawa et al., 2020; Proudfit, 2015; Proudfit et al., 2015). In adolescence, there is evidence to suggest that reward responsiveness is especially related to social contexts (Blakemore & Robbins, 2012; Crone & Dahl, 2012; Telzer, 2016). Thus, the investigation of how blunted reward responsiveness emerges across development, and the contextual factors that may impact reward responsiveness, provides critical insights into depression in adolescence.

A reliable measure of reward responsiveness across development, at the neural level of the RDoC framework, is the reward positivity (RewP). The RewP is an event-related potential (ERP), meaning neurophysiological activity tied to a specific, time-locked event, measured in response to rewards versus losses (Foti et al., 2011; Proudfit, 2015). Depression is thought to be driven in part by a lack of reinforcers in the environment, which contributes to the development and maintenance of the disorder. Consistent with this, neuroscience research has indicated that youth and adults with elevated depressive symptoms exhibit a blunted reward response (Kujawa & Burkhouse, 2017; Nusslock & Allo, 2017), potentially reflecting less motivation to seek out rewards or more difficulty adjusting behavior to obtain rewards. A blunted RewP has been shown to predict the development of depressive symptoms in community samples of adolescents (Bress et al., 2013, 2015; Kujawa et al., 2019; Nelson et al., 2016). Further, blunted RewP has been associated with more chronic courses of depression in adults (Bowyer et al., 2019). However, research with adolescents with clinical depression is more limited, and it is unclear the extent to which the RewP may track with symptom dimensions in clinical populations or whether the RewP may be impacted by social contexts and experiences. Examining individual differences in RewP in a clinical sample of adolescents, especially when considering both monetary and social reward responsiveness, may inform empirically derived subsets of adolescent depression (e.g., those with blunted versus relatively intact reward responsiveness), with implications for treatment targets (Burkhouse et al., 2016, 2018).

To date, most of the reward responsivity literature is focused on monetary reward tasks, but social reward may be particularly relevant given developmental changes in adolescence and the role of interpersonal relationships in depression. Ties between lack of social connectedness and internalizing psychopathology, most notably depression, have been demonstrated for decades (Fotti et al., 2006; Rohner & Britner, 2002) and previous work using the RewP has indicated that the motivational value of monetary and social incentives changes across development (Ethridge et al., 2017). Further, there is emerging evidence that low social, rather than monetary, reward responsiveness may be particularly related to depression in emerging adults (Pegg et al., 2021). Importantly, associations between depression and social reward responsiveness may depend in part on contextual factors. For example, Pegg and colleagues (2019) demonstrated that blunted social reward responsivity, measured by RewP, and greater social stress exposure interacted to characterize more depressive symptoms in emerging adults.

In addition to extending research on monetary reward to consider individual differences in social reward responsiveness, research on the contextual factors that shape reward responsiveness is needed. Experiences of positive emotions, and potentially reward responsiveness as well, are amplified in social interactions (Brown & Fredrickson, 2021), and parent-child relationships may be particularly important contexts for shaping the development of reward responsiveness. Prior research indicates that the combination of parental depression and low positive parenting in early childhood is associated with a more blunted RewP in late childhood, suggesting that aspects of the caregiving environment may moderate the effects of other risk factors on reward responsiveness (Kujawa et al., 2015). Across adolescence, parental relationships continue to play a key role in socioemotional development along with the increasing importance of peer relationships (Field et al., 2001; Hall-Lande et al., 2007; MacPhee & Andrews, 2006; Miller-Slough & Dunsmore, 2016). There is substantial work indicating that stress and depression are reciprocally related (Hammen, 2009), though how interpersonal stress relates specifically to reward responsiveness in adolescence is unclear. It may be that the iterative cycle of interpersonal conflict and depression fosters blunted reward responsiveness, raising questions about the independent and combined effects of aspects of parent-child relationships and depressive symptoms on RewP.

The primary aims of the present study were to examine the extent to which individual differences parent–child relationships are associated with reward responsiveness beyond or in combination with current depressive symptoms and to explore reward responsiveness in both the monetary and social domains. We focused on parental conflict as a proxy for relationships that are likely characterized by more interpersonal stress and less positive interactions and emotions. We examined these associations in a clinical sample of adolescents with depression, as it is currently unclear in the literature how the RewP tracks with symptom severity in clinical samples of youth. That is, we sought to examine the extent to which reward responsiveness varies as a function of depressive symptom severity and parental conflict in a sample already exhibiting clinically significant depression rather than examining risk for the development of symptoms. Moreover, examining reward responsiveness in a sample with clinical depression allows us to test the extent to which individual differences in a social context like parental conflict may be associated with reward responsiveness in a sample that would be expected to exhibit reduced reward responsiveness on average. We controlled for current anxiety symptoms in all analyses, as previous research has demonstrated that anxiety and depression symptoms may have opposite effects on reward and emotion ERPs (MacNamara et al., 2015; Proudfit et al., 2015; Weinberg et al., 2016). We hypothesized that greater parental conflict and higher depressive symptoms would be associated with blunted reward responsiveness, and that this association may be most apparent for social reward responsiveness. As an exploratory aim, we examined the effects of maternal and paternal parental conflict separately in relation to the RewP and depressive symptoms.

Method

Participants

Participants (N = 70) were adolescents 14–18 years of age (M = 15.81, SD = 1.46) with a current diagnosis of MDD and/or persistent depressive disorder (PDD) with at least moderate severity (> 4) on the Clinical Global Impression Scale (CGI; Guy, 1976). Participants were recruited through community and mental health clinics across two sites due to a relocation of the research lab (7.1% from Pennsylvania State College of Medicine and 92.9% from Vanderbilt University). Data from a subset of this sample completing the monetary reward task have been published previously (Pegg et al., 2020). Exclusion criteria included a diagnosis of mania, psychosis, intellectual or developmental disability, a substance use disorder severe enough to require treatment, or current use of antipsychotic medications and mood stabilizers. Current use of antidepressant medication was not exclusionary, and 36.92% of the sample endorsed current use of antidepressant medication. All were on stable dosages for the preceding 30 days to assessment. Participants were 65.7% female, 4.3% Hispanic/Latinx, 87.1% White/Caucasian, 4.3% Asian, 7.1% Black/African American, and 1.4% multiracial. Sample size was determined by a larger treatment study; post hoc power analysis revealed that the current analyses were powered at .62 to detect medium effects (f² = .15). Of the 70 participants enrolled, 66 completed the monetary reward task and 61 completed the social reward task. Three participants did not complete either parental conflict questionnaires and seven participants endorsed not having contact with their fathers and only completed the maternal conflict questionnaire.

Procedure

Study procedures were approved by the Institutional Review Boards at Pennsylvania State College of Medicine and Vanderbilt University. Data were obtained as part of a treatment study, and the current investigation uses only the pre-treatment data. Before the initiation of study procedures, informed consent was obtained from parents and assent obtained from minor participants. Informed consent was obtained directly from participants who were 18 years old. Participants completed diagnostic clinical interviews and self-report measures during an initial intake assessment. Eligible participants completed the social and monetary reward tasks while electroencephalogram (EEG) was recorded during a second session. On average, the intake and EEG assessments were completed 9.36 days apart (SD = 7.84).

Measures

Diagnostic Interview.

The DSM-V version of the Schedule for Affective Disorders and Schizophrenia for School Aged Children 6–18 years (K-SADS; Kaufman et al., 2013) was administered by clinical psychology doctoral students or masters-level clinicians to determine participants’ current and lifetime diagnoses. All adolescent participants were interviewed and for minors, parents were also interviewed. Interviews were supervised and diagnoses were verified by a licensed clinical psychologist (Dr. Kujawa). For current depression diagnoses, 28.6% met criteria for joint MDD and PDD (i.e., chronic MDD), 24.3% met for MDD only, 32.9% met for PDD with intermittent major depressive episodes (MDE) including a current MDE, 8.6% met for PDD with intermittent MDE without current MDE, and 5.7% met for PDD without a history of MDE. The average age of onset for current depressive episodes was 12.88 years (SD = 2.29) with an average episode duration of 111.46 weeks (SD = 117.23; range = 3.00–676.00). Comorbid diagnoses included 55.7% with at least one anxiety disorder (including social anxiety, generalized anxiety, panic, specific phobia, and separation anxiety disorder), 17.1% with attention-deficit/hyperactivity disorder, 4.3% with oppositional defiant disorder or conduct disorder. To evaluate inter-rater reliability, a subset of 8 audiotaped interviews were reviewed and coded by an independent interviewer, who agreed with the original depression diagnosis in all cases (kappa = 1.0 for MDD diagnoses; kappa = 1.0 for PDD diagnoses).

Depressive Symptoms.

Participants completed the 33-item Mood and Feelings Questionnaire (MFQ; Angold et al., 1987) as a dimensional measure of depressive symptoms. Items assess the extent to which participants have experienced each symptom in the past two weeks and are rated on a scale of 0 (not true), 1 (sometimes true), or 2 (true). MFQ scores ranged from 4.0–61.0 (M = 34.53), and internal consistency was excellent (Cronbach’s α = 0.94).

Anxiety Symptoms.

To obtain a dimensional measure of anxiety symptoms, participants completed the 13-item Emotional Distress-Anxiety-Pediatric Item Bank subscale of the Patient Reported Outcomes Measurement Information System (PROMIS; Pilkonis et al., 2011). Items are rated on a 5-point rating scale from 1 (never) to 5 (almost always) based on the extent to which participants have experienced those feelings in the prior 7 days. Scores on the PROMIS ranged from 13–55 (M = 31.32), and internal consistency was excellent (Cronbach’s α = 0.93).

Parent–Child Conflict.

The degree of conflict with parents was measured using adolescents’ reports on the Child Behavior Questionnaire (CBQ; Prinz et al., 1979). The CBQ is a 20-item true/false scale assessing the general level of conflict between children and each parent in the past two weeks. True/false responses were scored as 1/0, and a total score for each parent was computed by summing the coded items, with higher scores reflecting greater levels of conflict. Maternal CBQ scores ranged from 0–19 (M = 4.91) with excellent internal consistency (Cronbach’s α = 0.91). Paternal CBQ scores ranged from 0–16 (M = 4.80) with good internal consistency (Cronbach’s α = 0.88).

Social Reward Task.

Participants completed the Island Getaway task (Kujawa et al., 2014), which simulates social interactions between peers to measure participants’ neural responses to social feedback. Previous studies have shown that the task reliably elicits ERPs sensitive to social reward (i.e., peer acceptance feedback; Ethridge et al., 2017; Pegg et al., 2019). The task code is available at: https://github.com/Kodiologist/Survivor (branch: vanderbilt). At the beginning of the task, participants were instructed that they would be playing a game with 11 other adolescents participating in studies in other labs around the U.S. In reality, all co-players and responses were computerized. Participants’ goal was to be one of the 6 players who arrive at the “Big Island of Hawaii” without being kicked off by co-players. Prior to starting the task, participants provided a photograph of themselves that was used to create their player profile. Participants were asked to fill out questions about their name, age, hometown, school, and interests. Following the completion of their own profile, participants reviewed all co-players’ profiles, which were assembled by randomly assigning hometowns, ages, schools, interests, and stock photos designed to depict peers in a comparable age group.

Next, participants completed two practice voting rounds to become familiarized with the task. Participants were asked to either click to “keep” (accept) or “kick out” (reject) the co-player, and then saw how the co-player voted for them. After each vote, a fixation cross was shown for 1,000 ms, followed by co-player feedback lasting 2,000 ms, a blank screen for 1,500 ms, and then the profile of a new co-player. After the practice rounds, if participants voted faster than the designated decision-making time each co-player, a message appeared before the fixation cross saying “waiting for [co-player name] to vote” to increase participants’ beliefs in the interactive nature of the task. Participants were exposed to two types of feedback: a green thumbs up, which meant that the co-player voted to keep the participant in the game, indicating social acceptance/reward, and a red thumbs down, indicating that the co-player voted to kick the participant out of the game, indicating social rejection. After each of the first 5 rounds, a picture of a co-player who did not make it to the next round of voting was shown to the participants, and participants were prompted to answer a new poll question. Participants received approximately the same number of positive and negative votes across 51 trials. After the 6^th round, participants were told that they “won” and were among the 6 teens to get to the Big Island.

Monetary Reward Task.

In addition to the social reward task, participants also completed the Doors guessing reward task to measure monetary reward responsiveness (Bress et al., 2015; Kujawa et al., 2019), which is a validated and widely used task across development (Ethridge et al., 2017; Pegg et al., 2020; Proudfit, 2015). Participants were informed that they could win up to $5 in the task. On each trial, a pair of identical doors was presented, and participants were instructed to click either the left or right mouse button to choose which respective door had a reward behind it. Following their choice, a fixation cross was presented for 1,000 ms on the screen, followed by feedback that remained on the screen for 1,500 ms. Participants encountered two types of feedback: a green up arrow meaning that they chose correctly and won $0.50 (monetary reward), or a red down arrow indicating that they chose incorrectly and lost $0.25. After feedback for each round was presented, a fixation cross appeared for 1,000 ms followed by a screen with a statement prompting participants to click for another round. Participants completed 60 guessing trials, with 30 win and 30 loss trials that were presented in random order. At the end of the task, all participants won the full $5.

EEG Data Collection and Processing

Continuous EEG data were recorded with a 32-electrode cap using BrainProducts actiCHamp system (Munich, Germany). Facial electrodes were attached 1 cm above and below the left eye and 1 cm from the corners of each eye to measure electrooculogram from eye movements. The reference electrode for the facial electrodes was attached to the back of the participant’s neck, per the BrainProducts bipolar-to-auxiliary adapter design. The experimenter determined the correct positioning of the EEG cap according to the International 10/20 System. Conductive gel was applied to each of the electrodes, reducing impedance to approximately 10 kΩ. EEG data were referenced to Cz online and re-referenced offline to the average of the mastoid electrodes (TP9, TP10). A 1,000 Hz sampling rate was used to digitize recordings.

EEG data were analyzed using BrainVision Analyzer software (Brain Products, Munich, Germany). Data were band-pass filtered with cutoffs of 0.1 and 30 Hz and corrected for ocular movements according to approaches outlined by Gratton and colleagues (1983). Data were segmented 200 ms prior to and 800 ms following feedback. Faulty recordings at single electrode sites were interpolated using the signal from surrounding electrodes. For one participant with poor data at a mastoid electrode (TP10), data were interpolated at the mastoid prior to mastoid re-reference for the social reward task. Artifacts were removed using a semiautomated procedure according to the following criteria: voltage steps greater than 50 μV, maximum voltage difference of 175 μV, a minimal allowed amplitude of −200 μV and maximal allowed amplitude of 200 μV, and lowest allowed activity of 0.50 μV within 100 ms intervals, followed by visual inspection of the data to remove any remaining artifacts. ERPs were averaged separately across acceptance/win (reward) trials and rejection/loss (nonreward) trials and baseline corrected to the window 200 ms prior to feedback for both tasks. In accordance with previous studies, RewP was scored 250–350 ms at Cz for Doors (Foti & Hajcak, 2009; Pegg et al., 2020; Rappaport et al., 2019) and 275–375 ms at Cz for Island Getaway as the ERP tends to peak later in the social reward task (Ethridge et al., 2017; Rappaport et al., 2019). Unstandardized residual RewP (RewP to acceptance/win adjusting for RewP to rejection/loss) was calculated (Ethridge & Weinberg, 2018; Meyer et al., 2017). Monetary RewP and social RewP residual scores demonstrated excellent split-half reliability across odd/even trials, r_SB = .90 and r_SB = .94, respectively.

Data Analysis

Data were statistically evaluated using SPSS General Linear Model software (Version 26; SPSS Inc., Chicago, IL) and the lavaan package in R (R Core Team, 2020; Rosseel, 2012). Analyses were conducted with full information maximum likelihood (FIML) to handle missing data. First, the Pearson correlation coefficient (r) was used to examine bivariate associations. Next, multiple linear regression analyses were conducted to test the unique and interactive effects of parental conflict and depressive symptoms on reward responsiveness. The first model focused on social reward responsiveness, such that (1) the social RewP was regressed onto depressive symptoms, maternal conflict, paternal conflict, and each of their interactions with depression (i.e., maternal conflict x depression and paternal conflict x depression) and (2) the monetary RewP was similarly regressed onto depressive symptoms, maternal conflict, paternal conflict, and each of their interactions with depression. All models controlled for current anxiety symptoms. All independent variables were centered before modeling. Local effect sizes (i.e, Cohen’s f²) are reported (Selya et al., 2012). Significant interactions were probed by examining the simple slopes at levels of parental conflict indicated by the Johnson-Neyman technique. The Johnson-Neyman technique was utilized to assess the region of significance to determine at which values of the moderator the association between depressive symptoms and RewP were significant (Johnson & Neyman, 1936). Figures were created for simple intercepts, simple slopes, and regions of significance based on the output from MLR 2-way interactions tool (http://www.quantpsy.org/interact/mlr2.htm; Preacher et al., 2006)¹.

Results

Descriptive Statistics

Table 1 presents means, standard deviations, and bivariate correlations between study variables. All participants met diagnostic criteria for MDD or PDD; bivariate associations included current self-reported depressive symptoms. Figure 1 presents the grand-averaged waveforms and scalp topographies for the RewP elicited from each task. Monetary RewP amplitude significantly varied as a function of outcome such that the RewP was more positive for wins versus losses (t (65) = −5.78, p < .001); as did the social RewP (i.e., accept versus reject), t (60) = −.288, p = .005. The residual RewPs elicited in each task did not share a significant association with each other or with age, p’s > .273. Neither the monetary RewP nor social RewP significantly differed by gender, t (54) = −1.16, p = .250; t (49) = .641, p = .525, respectively. Depressive symptoms were significantly, positively associated with anxiety symptoms, but not monetary or social RewP.

Table 1.

Descriptive statistics and bivariate correlations between study variables

	M	SD	1	2	3	4	5	6	7
1. Depressive symptoms	34.53	14.85	-
2. Anxiety symptoms	31.77	11.68	.58*	-
3. Maternal conflict	4.91	5.20	.20	−.01	-
4. Paternal conflict	5.29	4.95	.03	−.17	.21	-
5. Social RewP	.00	4.90	.14	.19	−.09	−.16	-
6. Monetary RewP	.00	3.51	.02	−.02	<.01	.09	.02	-
7. Age	15.81	1.45	.13	−.10	.04	.14	−.01	.09	-
8. Gender (% female)	65.71%	−	.10	.32*	−.24	−.15	−.07	.18	−.26

Note.

^*p < .01.

Social RewP and Monetary RewP represent unstandardized residual RewP to acceptance/win adjusting for RewP to rejection/loss, respectively.

Fig.1.

ERP waveforms and scalp topographies for monetary (a) and social (b) reward processing. Panel (a) presents the ERP waveform and scalp topography for the monetary RewP. Panel (b) presents the ERP waveform and scalp topography for the social RewP in μV

Depressive Symptoms, Parental Conflict, and Social and Monetary Reward Responsiveness

Regression model results are presented in Table 2. The social RewP was regressed onto depressive symptoms, parental conflict (separately for mothers and fathers), and their interactions while controlling for concurrent anxiety to assess the moderating role of maternal and paternal conflict on the association between depressive symptoms and the social RewP. The overall model accounted for 25% of the variance in the social RewP, R² = .24². Notably, the most variance was explained when considering the interaction of current depressive symptoms and maternal conflict. The remaining predictors’ effects in the model were smaller and non-significant, all p’s > .097. The Johnson-Neyman technique and simple slopes analyses revealed that at high levels (+1 SD) of maternal conflict, more depressive symptoms were associated with a blunted social RewP (t (63) = −3.34, p = .001), but depressive symptoms did not significantly relate to the social RewP at mean levels of maternal conflict, t (63) = −0.58, p = .561 (Figure 2). Surprisingly, at low levels (−1 SD) of maternal conflict, more depressive symptoms were associated with a larger social RewP, t (63) = 2.17, p = .034. These analyses revealed that depression had a significant effect on the social RewP when maternal CBQ scores were lower than 0.04 or higher than 7.58; in the current sample, maternal CBQ scores ranged from 0–19.

Table 2.

Results of regression analyses examining depression symptoms and parental conflict in predicting reward responsiveness in social and monetary domains

Outcome: Social RewP	B	SE (B)	CI low	CI high	β	z	p	f2
Depressive symptoms	−0.03	0.05	−0.13	0.07	−.10	−0.63	.530	−.01
Anxiety symptoms	0.09	0.06	−0.03	0.21	.21	1.49	.138	.04
Maternal conflict	0.09	0.13	−0.17	0.34	.09	0.66	.511	<.01
Paternal conflict	−0.17	0.15	−0.46	0.12	−.17	−1.16	.246	.01
Depression × maternal conflict	−0.03	0.01	−0.05	−0.01	−.43	−3.22	.001	.13
Depression × paternal conflict	0.02	0.01	>−0.01	0.04	.28	1.66	.097	.07
Outcome: Monetary RewP	B	SE (B)	CI low	CI high	β	z	p	f2
Depressive symptoms	0.01	0.04	−0.08	0.09	.03	0.18	.858	.01
Anxiety symptoms	−0.01	0.05	−0.11	0.08	−.05	−0.29	.773	.01
Maternal conflict	0.01	0.11	−0.22	0.22	.02	0.10	.923	.01
Paternal conflict	0.06	0.13	−0.18	0.31	.09	0.52	.606	.01
Depression × maternal conflict	0.00	0.01	−0.01	0.02	.07	0.46	.651	<.01
Depression × paternal conflict	0.00	0.01	−0.01	0.02	.08	0.40	.694	.01

Note. B = Unstandardized regression coefficients. β = standardized regression coefficients. CI = 95% confidence interval.

Fig.2.

a) Simple slopes of the association between depressive symptoms and social RewP as at low (−1 SD), mean, and high (+1 SD) levels of maternal conflict. The residual difference social RewP is the unstandardized residual RewP calculated by regressing the RewP to acceptance onto the RewP to rejection. Self-reported depressive symptoms were assessed via the Mood and Feelings Questionnaire (MFQ). Maternal conflict was assessed via the Child Behavior Questionnaire (CBQ). b) Johnson-Neyman regions of significance for the association between depressive symptoms and social RewP at varying levels of maternal conflict (centered and corresponding to observed values range: −4.91–14.09). Dotted lines indicate the regions of significance, such that significant values are outside of the indicated region. Red lines indicate the 95% confidence interval of the simple slope

For monetary reward responsiveness, the monetary RewP was regressed onto depressive symptoms, parental conflict (separately for mothers and fathers), and their interactions while controlling for concurrent anxiety to assess the moderating role of maternal and paternal conflict on the association between depressive symptoms and the monetary RewP. The overall model accounted for 2.4% of the variance in the monetary RewP, R² = .02. Neither maternal conflict nor paternal conflict interacted with depressive symptoms in predicting the monetary RewP³.

Discussion

The primary aim of the present study was to examine the main and interactive effects of parental conflict and depressive symptoms on both social and monetary reward responsiveness in a clinical sample of adolescents with depression. Further, we examined the extent to which effects were specific to the social versus monetary reward. Results indicated that depressive symptoms interacted with maternal conflict in uniquely characterizing the RewP to social rewards. Specifically, higher levels of depressive symptoms and potentiated maternal conflict together were associated with an attenuated social RewP in this clinical sample. In contrast, parental conflict and depressive symptoms were not associated with the monetary RewP, suggesting specificity in the effects of maternal conflict on reward processing in the social domain. The current results in a clinical sample did not demonstrate a significant bivariate association between depressive symptoms and the RewP to monetary or social rewards. Similarly, measures of parental conflict were not significantly associated with the RewP.

The current results provide insight into potential factors shaping reward responsiveness among adolescents with depression. Interestingly, when considering the cumulative effects of depression symptoms and parental conflict, significant effects were specific to social reward responsiveness, supporting previous work that suggests the potential importance of considering social and monetary reward responsiveness separately (Distefano et al., 2018; Ethridge et al., 2017; Nelson & Jarcho, 2021; Pegg et al., 2021). For example, recent work demonstrated that previous peer victimization, especially victimization in early childhood, specifically relates to blunted social reward responsiveness, and not monetary reward responsiveness, in adolescence (Rappaport et al., 2019). Indeed, social motivation is particularly salient in adolescence and thus blunted social reward responsivity may be more salient in relation to depressive symptomatology during this period (Davey et al., 2008; Kujawa & Burkhouse, 2017; Pegg et al., 2019). Previous work has demonstrated that blunted social reward responsiveness and greater lifetime social stress together relate to greater depressive symptoms (Pegg et al., 2019) and the current study suggests that conflict in the parent–adolescent, and more specifically mother–adolescent, relationship interacts with depressive symptoms to predict social reward responsiveness.

Current depression symptoms and maternal conflict may be indices of state contextual factors that influence social reward responsiveness in combination. The current results are broadly consistent with previous work demonstrating that positive parental relationships are protective against adolescent depression (Field et al., 2001; Hall-Lande et al., 2007; MacPhee & Andrews, 2006; Miller-Slough & Dunsmore, 2016; Sentse et al., 2010) and that parent–offspring conflict is a salient social stressor in adolescence (Alaie et al., 2020; Marmorstein & Iacono, 2004; Nunez-Regueiro & Nunuez-Regueiro, 2021). Here, the combination of high levels of maternal conflict and more depressive symptoms were related to blunted social reward. This pattern is important in consideration of cyclical models of depression relapse and maintenance, particularly Hammen’s (2009) model wherein depressive symptoms may stem from interpersonal conflict and perpetuate future interpersonal conflicts. The present results suggest that this cycle may be further detrimental in that it is associated with blunted social reward responsiveness, which may be a key process underlying depression. Previous work has also demonstrated that a reduced RewP is associated with stress generation (Mackin et al., 2019), further supporting the notion that social conflict, depressive symptoms, and reward responsiveness may be associated in cyclical patterns. Surprisingly, at low levels of maternal conflict, greater depressive symptoms related to enhanced social reward responsiveness. Although this finding was unexpected, perhaps more positive social interactions (i.e., less conflict) shape increases in seeking out social rewards during difficult times (i.e., more depressive symptoms). Previous work supports this hypothesis in suggesting that relationships characterized by greater joint positive affect also amplify individual positive affective experiences (Brown & Fredrickson, 2021).

Further, we found significant effects of parental conflict on reward responsiveness for relationships with mothers but found no significant effect with fathers. Previous research suggests that this may be due to mothers serving as the primary providers of emotion socialization, such as opportunities for modeling emotional expressiveness, learning emotional labeling and understanding, and provision of recognition and reward for displays of various emotions (Brand & Klimes-Dougan, 2010). Thus, conflict in the mother–adolescent relationship may be particularly stressful or impactful to emotion experiences and emotion regulation development. Fathers also likely serve an important role in adolescent emotion socialization; however, 12% of the current sample reported being estranged from their fathers, which may have limited power. Critically, there is mounting work suggesting the need for parent–child relationship processes to be better integrated in the RDoC framework (King et al., 2021), and the current investigation supports that this is an important consideration in adolescent depression.

In addition to supporting calls for parent–offspring relationship processes to be better integrated in the RDoC framework (King et al., 2021), the current investigation also provides further understanding of the RDoC positive valence systems domain. Specifically, the RewP is thought to reflect the initial response to reward subconstruct of reward responsiveness and is measured at the physiological level of the matrix, with some insight into circuits given prior evidence that it reflects neural activation in the ventral striatum, ventromedial prefrontal cortex, midcingulate, and anterior cingulate cortex (Becker et al., 2014; Carlson et al., 2011; Foti et al., 2014; Liu et al., 2014). Given the focus on social reward, the current investigation examines the intersection of the affiliation and attachment subdomain in the social processes domain and initial reward response subdomain in the positive valence systems domain. Previous research demonstrated associations between low reward response and stress in predicting the emergence of psychiatric symptoms (Corral-Frias et al., 2015; Dennison et al., 2016; Goldstein et al., 2020; Kujawa et al., 2016, 2019, 2020; Sandre et al., 2019), and the current investigation suggests that these are complex and possibly cyclical associations. Overall, these findings contribute to RDoC advancements in investigating developmental and environmental influences (e.g., parent–adolescent conflict) on neural system functioning (e.g., RewP) (Mittal & Wakschlag, 2017).

Future investigations should consider repeated measures of conflict, symptoms, formal diagnoses, and reward responsiveness to more fully elucidate how these associations emerge across time and development. Longitudinal studies are needed to assess the possible bidirectional or cyclical relations and may offer further support for the proposed developmental models of social stress, reward responsiveness development, and depression cycles previously suggested. Currently, it remains unclear the associations across development and the degree to which each of these processes influence each other across time.

Perhaps demonstrating the complexity of these associations, the current results did not demonstrate a significant bivariate association between depressive symptoms and the RewP to monetary or social rewards. This may be because all of the participants in this sample were clinically depressed, and thus a bivariate association is examining heterogeneity within depression rather than the full range of possible depressive symptomatology across community samples. Of note, too, is the discrepancy between adolescent-reported depression symptoms and clinical interview with adolescent and parent diagnoses. Previous work has also demonstrated that the RewP—depressive symptoms link is small and not always observed (e.g., Ait Oumeziane & Foti, 2016; Burani et al., 2021; Hager et al., 2022), likely due in part to the need to consider other risk factors and moderating variables as done in the present investigation.

Strengths of the current study include the focus on adolescents with clinical depression and use of multimethod assessment including EEG measures of monetary and social reward, clinical interviews of psychiatric diagnoses, and self-report measures of current symptomatology and parental conflict. Assessing self-reported current depressive symptoms in a sample of adolescents with clinical depression enabled a dimensional approach to investigating current symptoms. One of the limitations of this study is the reliance on adolescent self-report, particularly for parental conflict; results may have varied if also taking into account parent report, and future investigations could consider including both adolescent and parent reports on conflict to assess cognitive biases or reporter mismatch. Relatedly, a second limitation is that the measurement of parent–adolescent relationship quality focused on conflict. While conflict is an important dimension of social relationships, it is not the only aspect relevant and future research is needed looking at more specific dimensions across development. A third limitation is the relatively small sample, which limits power and may have increased the likelihood of type II errors, decreasing the interpretability of null findings. The present sample was also composed predominantly of adolescents who identified as White and thus underrepresented many racial and ethnic minority groups. Family and parental conflict have been identified as important social stressors across nationally representative samples (Nunez-Regueiro & Nunuez-Regueiro, 2021). Further, research on mean RewP amplitudes (Hill et al., 2018) and the relation between the RewP and depression (Harold et al., in prep) have not revealed systematic differences amongst over- and under- represented groups. However, there are demonstrated differences in depressive symptom trajectories across racial and ethnic groups (Brown et al., 2007; Sen, 2004), and the lack of representativeness limits the generalizability of the present findings.

In conclusion, the current study builds on the large reward, social processes, and depression literatures by assessing the roles of monetary versus social reward responsiveness and parental conflict in adolescence, a developmental period particularly marked by social motivations. This investigation contributes to the understanding of adolescent depression, specifically highlighting maternal conflict as an environmental factor related to reward responsiveness in combination with current symptomatology. Given the role of maternal conflict, results suggest interventions focused on family processes may be particularly beneficial in reducing the ties between current symptoms and blunted reward responsiveness. Future investigations can build on this work by identifying how and when to most effectively target these processes when working with adolescents with clinical depression.