The study enrolled forty-eight adolescents who screened positive for subclinical eating-disorder symptoms. Participants were randomly assigned in equal numbers to an intervention group receiving the Unified Treatment or to a control group. The researchers assessed both groups at three time points: before treatment began, immediately after treatment ended, and again one month later. Rather than relying on simple comparisons of averages, the team analyzed the data using generalized estimating equations, a statistical framework well suited to repeated-measures designs because it accounts for the correlation between measurements taken from the same person over time and can handle non-normal outcome distributions.

The results were striking for emotion regulation. The trial found significant Group × Time interactions, meaning that the two groups changed differently over time. Adolescents who received the Unified Treatment showed substantially greater reductions in overall emotion regulation difficulties than those in the control condition, both immediately after treatment and at the one-month follow-up. The standardized between-group effect sizes were large: -1.97 at posttest and -1.58 at follow-up, both statistically significant at p < .001. In psychological intervention research, standardized effects of this magnitude are unusual; they suggest that the treatment did not merely nudge emotion regulation skills in the right direction but produced changes that were large relative to the variability observed between individuals.

For body image dissatisfaction, the picture was more nuanced. The Unified Treatment group again showed a greater reduction than the control group at posttest, with a standardized between-group effect of -0.32 and a p-value of .004. That is a small-to-moderate effect by conventional standards, but it was statistically reliable. However, by the one-month follow-up, the between-group difference had shrunk to -0.22 and was no longer statistically significant (p = .087). In plain terms, the improvement in how adolescents felt about their bodies did not clearly persist once the structured support of the treatment period ended, at least not in a way that distinguished them from the control group with statistical confidence.

Why would a treatment targeting emotion regulation produce such large and durable gains on that front, yet only short-lived gains on body image? The answer likely lies in the theory behind the intervention. The Unified Treatment, derived from the Unified Protocol for transdiagnostic treatment of emotional disorders, does not teach body-specific skills or challenge appearance-related beliefs one by one. Instead, it works on a common underlying mechanism: the tendency to avoid or suppress uncomfortable emotional experiences. The protocol helps participants identify and label emotions, increase their willingness to experience emotional discomfort without resorting to avoidance, and gradually approach situations and sensations they have been steering clear of. In the context of disordered eating, avoidance often takes the form of numbing distress through food restriction, bingeing, purging, or compulsive exercise, and of steering away from situations that trigger appearance anxiety.

Body image dissatisfaction, by contrast, is partly anchored in beliefs and evaluations that are specific to appearance—internalized beauty standards, habitual appearance comparison, and the meaning a person attaches to their shape and weight. A transdiagnostic mechanism-focused treatment may loosen the emotional avoidance that keeps these beliefs painful and unexamined, but it may not directly rewrite the beliefs themselves. The trial’s pattern of results is consistent with that interpretation: a mechanism-level intervention produced large, persistent change on the mechanism it targets (emotion regulation) and a smaller, less persistent change on an outcome that sits one step downstream (body image dissatisfaction). The authors themselves note that the lack of a significant between-group difference in body image dissatisfaction at follow-up highlights the need for further investigation in larger trials with longer follow-up periods.

The trial was registered in the Iranian Registry of Clinical Trials (IRCT20240813062749N1) on 14 November 2024, and it received ethical approval from the Research Ethics Committee of Tabriz University of Medical Sciences. The study was conducted in accordance with the Declaration of Helsinki, and written informed consent was obtained from all participants and their legal guardians. The research team—Nesa Amirfarshian and Leila Salek Ebrahimi of the Department of Clinical Psychology, Aarefeh Jafarzadeh Kohneloo of the Department of Statistics and Epidemiology, and Ayyoub Malek of the Clinical Psychiatry Research Center—declared no competing interests, and the work was supported by Tabriz University of Medical Sciences.

The clinical significance of subclinical symptoms deserves emphasis. Many adolescents who eventually develop anorexia nervosa, bulimia nervosa, or binge-eating disorder pass through a period in which their symptoms are noticeable but do not yet meet diagnostic criteria. Screening and early intervention during this window could prevent progression, but prevention requires treatments that are acceptable, scalable, and effective on the maintaining factors that drive the disorder. Emotion regulation difficulties and body image dissatisfaction are two of the most consistently identified maintaining factors in disordered eating across theoretical orientations. A treatment that reliably improves emotion regulation in this population therefore addresses a plausible causal pathway, even before disordered-eating behavior itself is the target.

The trial also illustrates the value of transdiagnostic thinking in adolescent mental health more broadly. Rather than developing a separate protocol for every presentation—appearance anxiety, mood dysregulation, anxiety, and disordered eating often co-occur in the same teenager—transdiagnostic approaches target shared mechanisms. If emotional avoidance is a common thread running through multiple problems, a single treatment that increases emotional awareness and willingness could, in principle, produce benefits across several domains at once. The large emotion regulation effects observed here lend preliminary support to that premise, at least for adolescents whose difficulties fall in the subclinical range.

Several caveats temper the enthusiasm. The sample of forty-eight adolescents is small by the standards of modern intervention trials, and small samples can produce unstable effect estimates, even when those estimates are statistically significant. The follow-up period of one month is short; it can detect whether gains persist briefly after treatment but cannot speak to durability over months or years. The body image findings, in particular, may look different with a larger sample, a longer follow-up, or a treatment that adds appearance-specific cognitive components to the transdiagnostic core. The authors are candid about these limitations, framing their results as preliminary support for the potential benefit of the Unified Treatment in this population rather than as definitive evidence of efficacy. Still, for a field searching for early, mechanism-focused interventions that can catch disordered eating before it takes hold, a trial showing large, persistent improvements in emotion regulation—and short-term improvements in body image dissatisfaction—offers a genuinely promising signal. The next step, the researchers suggest, is larger trials with longer follow-up to determine whether the body image gains can be consolidated and whether the emotion regulation improvements translate into reduced eating pathology over time.

Subject of Research: Unified psychotherapy for adolescent emotion regulation and body image

Article Title: A randomized controlled trial of the unified treatment for emotion regulation and body image dissatisfaction in adolescents with subclinical eating-disorder symptoms

Article References: Amirfarshian, N., Salek Ebrahimi, L., Jafarzadeh Kohneloo, A., & Malek, A. (2026). A randomized controlled trial of the unified treatment for emotion regulation and body image dissatisfaction in adolescents with subclinical eating-disorder symptoms. BMC Psychology. https://doi.org/10.1186/s40359-026-05653-5

Image Credits: AI Generated

DOI: 10.1186/s40359-026-05653-5

Keywords: adolescents, body image dissatisfaction, eating disorders, emotion regulation, randomized controlled trial, subclinical symptoms, transdiagnostic treatment, unified protocol, prevention, mental health, randomized, controlled