Randomized Controlled Trial of Spanish Brief Group Neuroscience-Informed Cognitive-Behavior Therapy for Anxiety

Anxiety is an anticipatory reaction to perceived threats, and may involve behavioral, cognitive, emotional, and physiological responses (Abend et al., 2020). Among U.S. Latino/a adults, 12.9% reported having an anxiety diagnosis (Powla et al., 2026). Yet the proportion of U.S. mental health facilities offering treatment in Spanish declined from 40.5% in 2014 to 33.3% in 2019, a net loss of 1,163 facilities (Pro et al., 2022). More recent data show that fewer than 10% of Latino/a adults received counseling in the prior year, while 5% reported needing therapy but were prohibited by cost (Powla et al., 2026). A treatment gap therefore exists from the confluence of limited Spanish-language services alongside financial and other structural barriers. Brief, community-based interventions that are culturally and linguistically responsive may help expand access to anxiety support for diverse Latino/a communities.

Cultural adaptation of an intervention improves fit with a population while preserving its core principles. Bernal et al. (1995) identified eight dimensions of fit, including language, metaphors, content, concepts, goals, methods, and context. Barrera et al. (2013) described adaptation as an iterative process of gathering information, testing modifications, and refining the intervention. A meta-analysis of 13 randomized controlled trials (RCTs) found a small but significant benefit of culturally adapted psychotherapy for depression and anxiety among Latino/a participants (Nelson et al., 2020). An RCT by Alegría et al. (2025) found that a 10-session Spanish-language culturally adapted psychoeducational intervention reduced anxiety and depression relative to enhanced usual care in a predominantly Latino/a adult sample. Cultural adaptation of a psychoeducational intervention thus holds promise in treating anxiety for Latino/a adults.

Psychoeducation is an intervention that combines teaching information about mental health symptoms and treatment with skills practice. Neuroscience-informed psychoeducation, or neuroeducation, is a content-specific variant of psychoeducation that uses accessible information about brain structure and function to help clients understand their experiences and practice regulation strategies (Miller, 2016). Although emerging research has begun to examine neuroeducation, it has received limited direct evaluation as a distinct clinical intervention (Rezapour et al., 2025). Because neuroeducation retains the same structure of psychoeducation, the broader evidence supporting psychoeducation provides indirect empirical foundation for use.

Group psychoeducation interventions for Spanish-speaking adults may retain effectiveness even when delivered in brief, time-limited formats. Peris-Baquero et al. (2025) reported that a five-session psychoeducational group intervention had similar efficacy to an eight-session format in reducing anxiety. Zhou et al. (2025) found that a brief CBT psychoeducational group reduced anxiety with gains maintained at three-month follow-up. Collado et al. (2014) found that a brief behavioral activation intervention delivered in Spanish improved treatment outcomes among Latino/a adults, with high rates of attendance and satisfaction. Brief psychoeducational group interventions for Spanish speakers, including CBT groups, thus appear both efficient and effective.

Neuroscience-informed Cognitive-Behavior Therapy Neuroscience-informed cognitive-behavior therapy (nCBT; Field et al., 2015, 2025) integrates dual processing theory (Kahneman, 2003) with rational emotive behavior therapy (Ellis, 1991) to explain how preconscious, bottom-up limbic processing (Wave1) and conscious, top-down cognitive appraisal (Wave2) each contribute to behavioral, emotional, and physiological responses to activating events. The model targets both waves therapeutically, helping clients increase awareness of and self-compassion toward reflective responses while developing reappraisal skills. The intervention includes neuroeducation on the Waves model.

nCBT has preliminary research support. In an uncontrolled study, counselors and clients described nCBT as credible and reported perceived improvement, particularly for anxiety and depression (Field et al., 2016). A feasibility study subsequently demonstrated that adherence and fidelity to core nCBT components could be rated consistently, supporting the model's capacity for standardized delivery (Field et al., 2019). A more recent study found evidence for anxiety reduction over a longer treatment duration of 20 sessions (Martin et al., 2026). Efficacy testing is needed as these studies did not include random assignment nor waitlist comparison.

Body Awareness and Self-Compassion in nCBT The Waves Model conceptualizes body awareness and self-compassion as regulatory processes associated with anxiety. Body awareness refers to interoceptive attentiveness to physiological experiences. Participants practice noticing and describing activation before responding. This adaptive noticing differs from anxiety sensitivity or threat-focused vigilance, in which arousal is interpreted catastrophically. Maladaptive sensitivity and vigilance can be associated with higher anxiety (Clemente et al., 2024), including among Latino/a adults (Zvolensky et al., 2015). The Waves model thus trains participants in a specific version of interoceptive body awareness that enhances positive experiences and regulation. Interoceptive sensibility has been found to mediate changes in anxiety (De Lima-Araujo et al., 2022).

Self-compassion involves responding to self-experiences with kindness rather than harsh intropunitive judgment, recognizing suffering as a common human experience (Neff, 2003). It may help tolerate activation while mitigating shame, self-criticism, and avoidance. A meta-analysis of randomized trials found that self-compassion interventions increased self-compassion and reduced anxiety, with stronger effects in group formats (Ferrari et al., 2019).

Measuring both body awareness and self-compassion in addition to anxiety as outcomes therefore tests two theoretically important constructs that are associated with anxiety reduction. Currently no studies have examined interventions that enhance body awareness and self-compassion as mechanisms for anxiety reduction among Spanish-speaking populations.

Working Alliance, Credibility, and Expectancy Outcomes in a brief group may depend not only on what is taught but also on how participants experience the intervention. Working alliance in groups refers to the participant-facilitator bond and agreement on goals and tasks. Positive working alliances are associated with improved outcomes in adult psychotherapy, and both member-leader and member-group alliance are associated with better group outcomes (Lo Coco et al., 2022).

Participant perceptions of treatment credibility and outcomes expectancy are modestly associated with positive therapeutic outcomes in meta-analytic literature (Constantino et al., 2018a; Constantino et al., 2018b). An intervention's credibility refers to whether an intervention appears logical and convincing. Expectancy is the belief that improvement will occur. The research team theorized that these constructs may be particularly relevant when evaluating an unfamiliar neuroscience-informed mode that is delivered in a culturally adapted format. Resonant explanations may support engagement and out-of-session practice. Earlier nCBT participants reported favorable credibility and expectancy (Field et al., 2016). These constructs therefore warranted examination as potential predictors rather than causal mechanisms.

Purpose of Study The purpose of this study was to evaluate whether a nCBT neuroeducational group can reduce anxiety in a scalable brief format suited to Spanish-speaking communities with limited access to counseling. No study has tested a culturally adapted, Spanish-language version of the nCBT Waves Model. This study additionally evaluated the effectiveness of a Spanish-language nCBT neuroeducational group intervention in enhancing body awareness and self-compassion. The study also examined whether treatment credibility, outcomes expectancy, and working alliance predicted change. The study addressed three research questions: (1) To what extent does group neuroeducation on the nCBT Waves Model reduce anxiety compared to a waitlist condition? (2) To what extent does group neurooeducation on the nCBT Waves Model enhance body awareness and self-compassion compared to a waitlist condition? (3) To what extent is anxiety reduction predicted by enhancements in body awareness and self-compassion, alongside the working alliance and credibility/expectancy? The study tested the following hypotheses: (1) Receiving group neuroeducation on the nCBT Waves Model will reduce anxiety to a greater degree than a waitlist condition; (2) Receiving group neuroeducation on the nCBT Waves Model will enhance body awareness and self-compassion to a greater degree than a waitlist condition; (3) A model consisting of body awareness, self-compassion, working alliance, and credibility and expectancy will predict anxiety reduction following nCBT group neuroeducation.

Design To test the hypotheses, the research team will conduct a randomized controlled trial with wait-list control and use stratified randomization to assign participants to the intervention or waitlist control condition. The study will be conducted in a naturalistic community setting, strengthening ecological validity and relevance. We obtained Institutional Review Board approval prior to study initiation.

Participants The research team will confirm eligibility and collect baseline measures prior to stratified randomization. At pre-registration, interested community members complete a signed informed consent document, a demographics questionnaire, and anxiety screening measure (PROMIS Anxiety Short Form, Spanish Version or PROMIS-A-SF-S; Teresi et al., 2016). The study has four inclusion criteria: (a) age 18 years or older, (b) identification as Latino/a, (c) Spanish fluency, (c) ability to attend three group sessions.

Randomized Assignment The research team will screen participants for eligibility at two community sites and enrolled them in the study over the course of a six month study period. The team will implement stratified randomization using gender, age, and baseline anxiety as variables to ensure consistency between groups. This approach strengthens internal validity and reduces the likelihood of baseline imbalances due to chance (Sidani \& O'Rourke, 2022).

To support single-blinding, the research team will not disclose assigned condition at the time of inclusion and waitlist participants will not know their assignment. Because of the short study duration (28 days) and facilitation of multiple concurrent groups, community members were unlikely to know their assignment on the basis of conversations with other members. Wait-list participants will receive the group intervention only after the initial study period ends.

The nCBT Waves Model Psychoeducation Intervention The intervention consists of three 90-minute neuroeducational group sessions that follow three sequential phases from the nCBT treatment manual (Beeson et al., 2017). Session 1 corresponds with the first phase, Attending to Physiological Reactions, and focuses on developing therapeutic rapport, assessing needs, and conceptualizing treatment. Session 2 corresponds with the second phase, Build the Brain from the Bottom-Up, and focuses on helping participants prevent and regulate, rather than reactively respond to, Wave1 physiological activation and dysregulation. Session 3 corresponds with the third phase, Connect Bottom to the Top, and introduces strategies for tolerating activation and reappraising Wave1 responses.

Intervention Fidelity To support intervention fidelity, an original nCBT model co-author will provide a two-day, 12-hour virtual nCBT training to the counselor who delivered the intervention. The co-author will observe the counselor's demonstration with a simulated client to determine competency and readiness using an nCBT treatment fidelity measure (Field et al., 2019). The co-author will also review the group materials before the study began, and will meet with the counselor on a regular basis throughout the study to review implementation and monitor fidelity.

Cultural Adaptation and Piloting To prepare study materials for participant use, the research team refined the intervention through several stages in alignment with Barrera et al. (2013). First, the team developed group outlines and handouts that aligned most closely with the nCBT Waves Model. Second, the team evaluated the comprehensibility and cultural relevance of all materials and translated them into Spanish. Third, the team assessed all eight dimensions of cultural fit per Bernal et al. (1995), such as language, metaphors, content, concepts, goals, methods, and context. Fourth, Spanish-speaking clinicians outside the study then reviewed the translated materials and handouts, and the team revised them to incorporate feedback. Fifth, the team conducted a final check of cultural and linguistic fit by piloting the curriculum and handouts with community members.

The research team also piloted the instrument packet. Spanish-speaking doctoral counseling students reviewed materials and completed the instruments to provide feedback. The team adjusted materials post-piloting by reducing the number of items in the instrument packet. For example, the team selected a briefer body awareness instrument.

Power Analysis The research team conducted a power analysis using G*Power 3.1.9.4 (Faul et al., 2007) to determine the minimum sample size required for a large effect size with 80% power at an alpha level of .05, for three tests: (a) repeated-measures ANCOVA, (b) Welch's independent samples t-test, and (c) multiple regression with four predictors. The team selected a large effect because psychotherapy studies with a waitlist condition often yield large between-group effects (Cuijpers et al., 2024). Minimum required sample sizes were 52 for ANCOVA, 42 for t-test, and 36 for multiple regression.

Procedure The research team will recruit participants in partnership with two community-based agencies serving Spanish-speaking communities in the Mountain West region of the United States. The team will distribute recruitment information through flyers posted in high-traffic community locations. In addition, the team will ask agency staff to share flyers with established community members and partner organizations. The flyers will provide information about the group structure, study duration, participant incentives, and contact information. The team will hold orientation meetings at both sites to explain the study purpose, potential benefits, risks, expectations, and eligibility criteria. Participants will receive contact information for the research team in the event of an emergency.

Instruments Participants will complete Spanish-language instruments that measured anxiety, body awareness, self-compassion, working alliance, and intervention credibility and outcomes expectancy. They will complete the anxiety, body awareness, and self-compassion measures at the end of each session. They will complete the working alliance and intervention credibility/expectancy measures at the end of the third and final session.

PROMIS Anxiety Short Form 6a - Spanish (PROMIS-A-SF-S) The PROMIS-A-SF-S (Patient-Reported Outcomes Measurement Information System, 2012; Teresi et al., 2016) measures anxiety symptoms over the past 7 days with higher scores indicating greater anxiety severity. Participants rate each item on a five-point Likert scale from 1 (never) and 5 (always). The PROMIS-A-SF has strong internal consistency (Cronbach's α = .97).

Body Awareness Questionnaire - Spanish Version (BAQ-S) The BAQ-S (Sánchez-Sánchez et al., 2025) measures sensitivity to normal, non-emotive bodily processes. Participants rate items on a seven-point Likert scale from 1 (not at all true of me) to 7 (very true of me). Higher scores indicate greater body awareness. The Spanish version has good internal consistency (Cronbach's α = .82).

Self-Compassion Scale - Short Form, Spanish Version (SCS-SF-S) The SCS-SF-S (García-Campayo et al., 2014) measures perceived self-compassion during difficult moments. Participants rate items on a five-point Likert scale from 1 (almost never) to 5 (almost always). Higher scores indicate greater self-compassion. The Spanish version has good internal consistency (Cronbach's α = .85).

Spanish-Language Working Alliance Inventory-Short for Patients, Revised (WAI-S-P) The WAI-S-P (Andrade-González \& Fernandez-Liria, 2016) measures the therapeutic alliance from the participant's perspective. Participants rate items on a seven-point Likert scale from 1 (seldom/never) to 7 (always). The Spanish version has strong internal consistency (Cronbach's α = .93).

Credibility and Expectancy Questionnaire The CEQ (Devilly \& Borkovec, 2000) contains six items measuring treatment credibility and outcome expectancy. The study used the nCBT-adapted version of the CEQ from Field et al. (2016). Participants rate six items on a 10-point Likert scale from 1 (not at all) to 10 (very much). Participants rate two items as percentages from 0 to 100%. The percentage items are converted to a 1-10 scale to compute a total score for the instrument, consistent with Field et al. (2016). Because no formally validated Spanish version currently appears in the published literature, the research team translated the CEQ into Spanish. The English version has strong internal consistency (Cronbach's α = .90; Devilly \& Borkovec, 2000).

Data Analysis Plan The research team will assign participants a unique identification number to preserve anonymity. The team will clean and prepare the database prior to conducting statistical analyses. The team will use imputation to determine scores of missing data points, following the multiple imputation (MICE) method that uses data from all other participants at the same interval to predict the missing value. A repeated-measures ANCOVA will compare endpoint PROMIS-A-SF-S anxiety scores between groups while controlling for baseline anxiety. A complementary Welch's independent-samples t-test will compare baseline-to-endpoint anxiety change scores (ΔPROMIS-A-SF-S) between groups. For body awareness and self-compassion outcomes, a Welch's independent-samples t-test will compare between-group endpoint scores. The team will calculate calculated effect sizes using Hedges' g for t-tests and partial η² for ANCOVA. A multiple linear regression analysis will test whether changes in body awareness (ΔBAQ-S), self-compassion (ΔSCS-SF-S), working alliance (WAI-S-P), and credibility and expectancy (CEQ) predict anxiety change (ΔPROMIS-A-SF-S).

Assumption Checks The research team will examine assumptions before conducting the ANCOVA, t-test, and regression. These include Shapiro-Wilk distribution of residuals, Levene's test for homogeneity of variance, Q-Q plots for deviation from normality, homogeneity-of-regression-slopes assumption, and correlations, variance inflation factor (VIF) values, tolerance statistics, and Durbin-Watson values.