Striatal reactivity to reward under threat-of-shock and working memory load in adults at increased familial risk for major depression: A preliminary study.

INTRODUCTION: Anhedonia, a core symptom of Major Depressive Disorder (MDD), manifests as a lack or loss of motivation as reflected by decreased reward responsiveness, at both behavioral and neural (i.e., striatum) levels. Exposure to stressful life events is another important risk factor for MDD. However, the mechanisms linking reward-deficit and stress to MDD remain poorly understood. Here, we explore whether the effects of stress exposure on reward processing might differentiate between Healthy Vulnerable adults (HVul, i.e., positive familial MDD) from Healthy Controls (HCon). Furthermore, the well-described reduction in cognitive resources in MDD might facilitate the stress-induced decrease in reward responsiveness in HVul individuals. Accordingly, this study includes a manipulation of cognitive resources to address the latter possibility. METHODS: 16 HVul (12 females) and 16 gender- and age-matched HCon completed an fMRI study, during which they performed a working memory reward task. Three factors were manipulated: reward (reward, no-reward), cognitive resources (working memory at low and high load), and stress level (no-shock, unpredictable threat-of-shock). Only the reward anticipation phase was analyzed. Imaging analyses focused on striatal function. RESULTS: Compared to HCon, HVul showed lower activation in the caudate nucleus across all conditions. The HVul group also exhibited lower stress-related activation in the nucleus accumbens, but only in the low working memory (WM) load condition. Moreover, while stress potentiated putamen reactivity to reward cues in HVul when the task was more demanding (high WM load), stress blunted putamen reactivity in both groups when no reward was at stake. CONCLUSION: Findings suggest that HVul might be at increased risk of developing anhedonic symptoms due to weaker encoding of reward value, higher difficulty to engage in goal-oriented behaviors and increased sensitivity to negative feedback, particularly in stressful contexts. These findings open new avenues for a better understanding of the mechanisms underlying how the complex interaction between the systems of stress and reward responsiveness contribute to the vulnerability to MDD, and how cognitive resources might modulate this interaction.

Increased Reward-Related Activation in the Ventral Striatum During Stress Exposure Associated With Positive Affect in the Daily Life of Young Adults With a Family History of Depression. Preliminary Findings.

Background: Being the offspring of a parent with major depression disorder (MDD) is a strong predictor for developing MDD. Blunted striatal responses to reward were identified in individuals with MDD and in asymptomatic individuals with family history of depression (FHD). Stress is a major etiological factor for MDD and was also reported to reduce the striatal responses to reward. The stress-reward interactions in FHD individuals has not been explored yet. Extending neuroimaging results into daily-life experience, self-reported ambulatory measures of positive affect (PA) were shown to be associated with striatal activation during reward processing. A reduction of self-reported PA in daily life is consistently reported in individuals with current MDD. Here, we aimed to test (1) whether increased family risk of depression is associated with blunted neural and self-reported reward responses. (2) the stress-reward interactions at the neural level. We expected a stronger reduction of reward-related striatal activation under stress in FHD individuals compared to HC. (3) the associations between fMRI and daily life self-reported data on reward and stress experiences, with a specific interest in the striatum as a crucial region for reward processing. Method: Participants were 16 asymptomatic young adults with FHD and 16 controls (HC). They performed the Fribourg Reward Task with and without stress induction, using event-related fMRI. We conducted whole-brain analyses comparing the two groups for the main effect of reward (rewarded > not-rewarded) during reward feedback in control (no-stress) and stress conditions. Beta weights extracted from significant activation in this contrast were correlated with self-reported PA and negative affect (NA) assessed over 1 week. Results: Under stress induction, the reward-related activation in the ventral striatum (VS) was higher in the FHD group than in the HC group. Unexpectedly, we did not find significant group differences in the self-reported daily life PA measures. During stress induction, VS reward-related activation correlated positively with PA in both groups and negatively with NA in the HC group. Conclusion: As expected, our results indicate that increased family risk of depression was associated with specific striatum reactivity to reward in a stress condition, and support previous findings that ventral striatal reward-related response is associated with PA. A new unexpected finding is the negative association between NA and reward-related ventral striatal activation in the HC group.

Striatal responsiveness to reward under threat-of-shock and working memory load: A preliminary study.

INTRODUCTION: Reward and stress are important determinants of motivated behaviors. Striatal regions play a crucial role in both motivation and hedonic processes. So far, little is known on how cognitive effort interacts with stress to modulate reward processes. This study examines how cognitive effort (load) interacts with an unpredictable acute stressor (threat-of-shock) to modulate motivational and hedonic processes in healthy adults. MATERIALS AND METHODS: A reward task, involving stress with unpredictable mild electric shocks, was conducted in 23 healthy adults aged 20-37 (mean age: 24.7 ± 0.9; 14 females) during functional magnetic resonance imaging (fMRI). Manipulation included the use of (a) monetary reward for reinforcement, (b) threat-of-shock as the stressor, and (c) a spatial working memory task with two levels of difficulty (low and high load) for cognitive load. Reward-related activation was investigated in a priori three regions of interest, the nucleus accumbens (NAcc), caudate nucleus, and putamen. RESULTS: During anticipation, threat-of-shock or cognitive load did not affect striatal responsiveness to reward. Anticipated reward increased activation in the ventral and dorsal striatum. During feedback delivery, both threat-of-shock and cognitive effort modulated striatal activation. Higher working memory load blunted NAcc responsiveness to reward delivery, while stress strengthened caudate nucleus reactivity regardless reinforcement or load. CONCLUSIONS: These findings provide initial evidence that both stress and cognitive load modulate striatal responsiveness during feedback delivery but not during anticipation in healthy adults. Of clinical importance, sustained stress exposure might go along with dysregulated arousal, increasing therefore the risk for the development of maladaptive incentive-triggered motivation. This study brings new insight that might help to build a framework to understand common stress-related disorders, given that these psychiatric disorders involve disturbances of the reward system, cognitive deficits, and abnormal stress reactivity.

Short-Term Effects of a Multidimensional Stress Prevention Program on Quality of Life, Well-Being and Psychological Resources. A Randomized Controlled Trial.

It is well-documented that university students have an increased risk in developing psychological problems because they face multiple stressors. Cognitive, behavioral, and mindfulness-based stress prevention programs were shown to reduce symptoms of anxiety, depression, and perceived stress in university students. However, little is known of their effect on resource activation. Additionally, most validated interventions are unidimensional, i.e., including one stress-coping approach. In this study, we investigated the short-term effects of a multidimensional stress prevention program on students' quality of life, psychological symptoms and resources, and resilience factors against stress. Using an experimental design, 64 healthy undergraduate students (56 women), between 18 and 34 years old (M = 21.34, SD = 2.53), from the University of Fribourg, Switzerland, were randomly allocated either to the intervention or the wait-list control group. The intervention group participated in a multidimensional stress prevention program, integrating mindfulness-based activities, cognitive and behavioral strategies, social skills, and emotional regulation exercises. The program consisted of eight 2-h weekly sessions. Before and after the intervention, participants completed self-reported questionnaires evaluating quality of life; psychological symptoms such as depression, anxiety, social anxiety, and interpersonal problems; as well as psychological resources like self-efficacy, sense of coherence, self-compassion, and social support, presented online. A standardized clinical interview was performed at pre- and post-measurement times. To analyze the sort-term effects of the program, we used mixed, two-factorial ANOVAs (per-protocol analyses). In accordance with our hypotheses, our results showed significant reduction of psychological symptoms, including anxiety, interpersonal problems, and symptoms of pain; a significant increase in quality of life, sense of coherence, and self-compassion in students who participated in the intervention program compared to the control group, (all p < 0.05). No significant results were found for symptoms of depression, social anxiety, self-efficacy, and social support. These preliminary findings indicate specific short-term effects of our multidimensional stress prevention program on psychological symptoms and on quality of life as well as promising effects on psychological resources and factors associated with resilience against stress. Future studies should investigate the long-term effects of the intervention as well as the effects in clinical samples.

Warm-hearted businessmen, competitive housewives? Effects of gender-fair language on adolescents' perceptions of occupations.

Recent studies from countries with grammatical gender languages (e.g., French) found both children and adults to more frequently think of female jobholders and to consider women's success in male dominated occupations more likely when the jobs were described in pair forms (i.e., by explicit reference to male and female jobholders, e.g., inventeuses et inventeurs; French feminine and masculine plural forms for inventors), rather than masculine only forms (e.g., inventors). To gain a better understanding of this phenomenon, we systematically varied the gender connotation of occupations (males overrepresented, females overrepresented, equal share of males and females) and measured additional dependent variables, predicting that gender fair language would reduce the impact of the gender connotation on participants' perceptions. In a sample of 222 adolescents (aged 12-17) from French speaking Switzerland, we found that pair forms attenuated the difference in the ascription of success to male and female jobholders in gendered occupations and attenuated the differential ascription of warmth to prototypical jobholders in male vs. female dominated jobs. However, no effect of language form on the ascription of competence was found. These findings suggest that language policies are an effective tool to impact gendered perceptions, however, they also hint at competence-related gender stereotypes being in decline.