A Synergistic Mindsets Intervention Protects Adolescents from Social Stress

Abstract

Social stress poses a major threat to adolescent health via its effects on internalizing symptoms, such as anxiety and depression. Available interventions to help adolescents improve their stress responses, however, have not been effective in rigorous evaluation studies, or they have been difficult to administer widely. Here we show that replicable improvements in adolescent stress responses can be achieved with a short (~30-minute), scalable synergistic mindsets intervention. This intervention, which is a self-administered online training module, targets both growth mindsets (the idea that people's intelligence can be developed in response to challenge) and stress-can-be-enhancing mindsets (the idea that people's stress responses can be fuel for optimal performance). Its goal is to promote positive engagement with stressful events (e.g., learning from failure on a quiz or a conflict with a peer) and to encourage adolescents to use their responses to stressful events and even their bodily symptoms (e.g. racing heart, sweaty palms, butterflies in their stomach) to their advantage. In five double-blind, randomized, controlled trials (total N = 4,091 adolescents), the new synergistic mindsets intervention improved stress-related cognitions (Studies 1-2), cardiovascular reactivity (Study 3), daily internalizing symptoms and cortisol levels (Study 4), and generalized anxiety symptoms during the 2020 COVID-19 lockdowns (Study 5). Effects on downstream outcomes (in Studies 3-5) were stronger among individuals who, at baseline, held the two negative mindsets targeted by the intervention, providing evidence for the proposed mechanisms. Confidence in this conclusion comes from a conservative, Bayesian machine-learning method for detecting heterogeneity.

Figure 1

The model guiding the present study’s predictions. (A) In an acute situation, differences in appraisals lead to differences in challenge versus threat responses. (B) Mindsets lead to differences in appraisals and shape responses in acute situations and across situations over time. In the event appraisal stage, stressors are appraised as harmful/uncontrollable or more helpful/controllable, cultivating threat or challenge response tendencies, respectively. Then, at the response appraisal stage, when individuals actively engage with stressors, the meaning of their stress response is appraised as either distressing and non-functional (harmful/uncontrollable) or as a resource that helps one address situational demands (helpful/controllable), resulting in further threat or challenge type stress responses, respectively. As shown in Panel A, challenge and threat responses differentially activate stress axes in the brain. Although both elicit sympathetic-adrenal-medullary (SAM) activation, threat also stimulates the hypothalamic-pituitary-adrenal (HPA) axis, the end-product of which is the catabolic adrenal hormone cortisol, in anticipation of damage or social defeat. Challenge is characterized by increased peripheral blood flow (which is why it is depicted in red), and an agile response onset/offset: resources are mobilized rapidly, and individuals return to homeostasis quickly after stress offset. Threat, however, results in increased vascular resistance and less oxygenated blood flow to the periphery (which is why it is depicted in blue) as HPA activation tempers SAM effects and produces a more prolonged stress response than challenge due to the longer half-life of cortisol compared to anabolic hormones. Challenge and threat then have different consequences for motivation and affective responses. Whereas threat leads to avoidance motivation and negative affect, challenge elicits approach motivation and more positive affect relative to threat. As shown in (B) mindsets are situation-general beliefs about categories of events (e.g., academic stressors) and responses (e.g., feelings of worry). The mindsets shape appraisals at the event stage and next at the response stage. Thus, mindsets “count twice” toward the construction of affective responses. Downstream, if individuals respond with an optimized challenge type stress response, this increases the likelihood they will engage with and respond to future stressors more adaptively in a self-reinforcing, positive feedback cycle, the end result of which is buffering against internalizing symptoms (bottom right in panel B).

Figure 2

Two experiments (Study 1 N = 2,717; Study 2 N = 755) showed that the synergistic mindsets intervention reduced negative appraisals of an immediate, hypothetical stressor (A, B), and an acute naturalistic stressor up to 3 weeks post-intervention (C, D). Note: Starbursts represent stressor onset. Results estimated with the BCF algorithm. Thick lines represent the 10th to 90th %iles; gray lines represent the 2.5th to 97.5th %iles. ATE = average treatment effect. The appraisals for each study were coded so that higher values meant more negative appraisals, so negative treatment effects are consistent with a beneficial stress optimization effect. Effect sizes appear in the text.

Figure 3

In Study 3 (N = 160), the synergistic mindsets intervention improved cardiovascular responses to the Trier Social Stress Test (TSST) overall (B,D) and especially for participants with negative prior mindsets during the most stressful epochs (C, E). Note: ATE = Average treatment effect. CATE = Conditional average treatment effect. TPR = total peripheral resistance (in dyne-sec x cm5). ICG = Impedance cardiography. BP = Blood pressure. ECG = Electrocardiography. Time indicates elapsed, cumulative physiological recording. TSST = Trier Social Stress Test. Starbursts indicate TSST epochs that presented acute demands (i.e., the stressful epochs). Baseline measurements were taken prior to the stress induction and random assignment to condition, preparation measurements were taken after intervention materials when participants planned their speech, speech delivery and mental math measurements were taken during the speech and math tasks, respectively, and finally measurements during a recovery period, where evaluative pressure (i.e., stress) was removed, tracked recovery to baseline. Data reported here control for baseline values. Thick / colored lines represent the 10th to 90th %iles; gray lines represent the 2.5th to 97.5th %iles. ATEs and 10th to 90th%iles for Preparation = −158.307 dyne-sec x cm5 [−212.458, −102.174], Speech = −221.976 [−276.696, −165.540], Math = −118.571 [−171.965, −36.903], Recovery = −76.245 [−132.624, −17.962]. The prior mindset subgroups used to display treatment effects in (C) and (E) were generated by implementing a hands-off Bayesian decision-making algorithm that maximized the differences among the mindset groups in terms of the outcome, without using information on the magnitudes of the treatment effects (see online supplemental material).

Figure 4

In Study 4 (N = 118, n <= 1213 observations), the synergistic mindsets intervention reduced internalizing symptoms overall and especially on intensely stressful days (B,D). The intervention also reduced daily salivary cortisol levels overall (C, E). Note: Starbursts represent stressor measurements. Univariate marginal distribution plots are over panels B and D. Thick / colored lines represent the 10th to 90th %iles; gray lines represent the 2.5th to 97.5th %iles. The vertical dashed line in (B) represents the cut-point for high vs. low daily stress intensity used to estimate subgroup CATEs in (D). In (D), the unstandardized CATE for high daily stress intensity was −.475 scale points [−.813, −.138]; for low daily stress intensity it was −.225 scale points [−.437, −.015].

Figure 5

In Study 5 (N = 341) a synergistic mindsets intervention reduced general anxiety symptoms during the Spring 2020 COVID-19 quarantine among late adolescents with negative prior mindsets, and did not reduce anxiety among late adolescents with positive prior mindsets. (A) In January of 2020, participants answered prior negative mindset questions and completed the short mindset treatment or control exercise. Two and a half months later, during the first wave of stay-at-home orders during the COVID-19 pandemic in April of 2020, participants completed the Generalized Anxiety Disorder symptom assessment. (B) The treatment reduced anxiety symptoms by −.967 scale points [−2.086, .000] among those reporting negative prior mindsets and did not meaningfully reduce symptoms among those reporting positive prior mindsets, −.079 scale points [−.892, .738], (C) An additive summary of the posterior distribution of treatment effects shows greater reductions in anxiety in response to the treatment among those with negative prior mindsets. (D) Although there was a small posterior probability of a null treatment effect among prior negative mindsets participants, there was a higher probability of effects > .30 SD. The prior mindset subgroups used to display treatment effects in (B) and (D) were generated by implementing a hands-off Bayesian decision-making algorithm that maximized the differences among the mindset groups in terms of the outcome, without using information on the magnitudes of the treatment effects (see online supplemental material).