The letter arrives as a direct response to an updated meta-analysis of randomized controlled trials of acceptance and commitment therapy for insomnia, published earlier in the same journal by Barroso and colleagues. That meta-analysis pooled trial data to estimate how well ACT performs against control conditions and other active treatments, and its findings have been interpreted by some as support for expanding ACT’s footprint in behavioral sleep medicine. Saripudin and Saputri do not dispute the underlying data. Instead, they use the meta-analysis as a springboard to ask a more fundamental question: are current trials of ACT for insomnia designed well enough to tell us where the therapy genuinely helps, for whom, and at what point in a treatment pathway it should be deployed?

Acceptance and commitment therapy differs from standard CBT-I in a philosophically and mechanically important way. Rather than targeting sleep directly through stimulus control, sleep restriction, and cognitive restructuring of dysfunctional beliefs about sleep, ACT draws on relational frame theory and psychological flexibility research, a framework codified by Steven Hayes and colleagues in their foundational 2006 model of the approach. In the insomnia context, this means helping patients observe their sleep-related thoughts and anxieties without struggling against them, defusing from catastrophic predictions about the consequences of a bad night, and redirecting energy toward valued activities regardless of how sleep unfolds. The metacognitive model of insomnia developed by Ong, Ulmer, and Manber in 2012 provides the theoretical scaffolding here: insomnia is maintained not simply by poor sleep but by excessive monitoring of sleep, worry about sleep, and futile efforts to control a largely involuntary process.

The first methodological challenge highlighted by the letter concerns the heterogeneity of what actually gets called ACT in insomnia trials. Component network meta-analysis of CBT for chronic insomnia, such as the 2024 systematic review by Furukawa and colleagues in JAMA Psychiatry, has shown that the specific ingredients bundled inside a treatment package matter, and that different delivery formats produce different effect sizes. When one trial delivers pure acceptance and defusion exercises while another folds in sleep restriction, relaxation training, and psychoeducation under the ACT banner, the pooled estimate from a meta-analysis becomes difficult to interpret. Saripudin and Saputri argue that future trials must specify and measure the treatment components with the same rigor applied to pharmacological dosing, otherwise clinicians cannot know whether it is the acceptance processes or the borrowed behavioral elements driving observed improvements.

A second challenge involves the measurement of the very mechanisms ACT claims to target. If psychological flexibility, acceptance, and defusion are the active ingredients, then trials should track changes in these processes and demonstrate that they mediate sleep outcomes. Many existing studies measure only symptom endpoints such as insomnia severity or sleep-onset latency, leaving a black box between intervention and effect. Without mediation analyses and process measures, the field cannot distinguish a genuine mechanism-driven therapy from a repackaged relaxation intervention. The letter’s authors contend that this measurement gap is not a technical detail but the central scientific question, because it determines whether ACT is a distinct therapeutic modality for insomnia or simply a sympathetic framing of existing techniques.

The third pillar of the letter is the proposal to integrate ACT into a stepped-care architecture for insomnia. Stepped-care models allocate treatment intensity according to severity and prior response, beginning with low-intensity, widely accessible interventions and escalating only when needed. In such a system, ACT could occupy a strategically valuable position: for patients who refuse or fail sleep restriction, for those whose insomnia is entangled with chronic pain, anxiety, or depression, and for individuals whose primary problem is the struggle against sleep rather than sleep itself, acceptance-based approaches may be more acceptable and more effective than classic CBT-I protocols. Positioning ACT as either a first-line option for struggle-dominant presentations or a second step after CBT-I nonresponse is, in the authors’ view, a testable and clinically meaningful hypothesis that current trial designs have not yet addressed.

Underpinning this stepped-care argument is the often-overlooked issue of acceptability. Research on adherence to CBT-I, including the systematic review by Matthews and colleagues published in Sleep Medicine Reviews, has documented that many patients abandon sleep restriction partway through, and studies of patient perceptions toward insomnia treatments by Cheung and colleagues have shown that people frequently hold reservations about behavioral prescriptions that initially worsen sleep. Acceptability, the letter argues, should be treated as a formal outcome metric rather than an afterthought. Trials should systematically quantify tolerability, dropout attributable to treatment burden, patient-rated willingness to continue, and the match between treatment demands and patient preferences. If ACT’s chief comparative advantage is that patients will actually do it, then the field needs standardized instruments to demonstrate that advantage rather than relying on anecdote.

The implications of the letter extend beyond behavioral sleep medicine into health policy and service design. Insomnia affects a substantial share of adults, contributes to accidents, cardiovascular and metabolic disease, and psychiatric morbidity, and consumes enormous healthcare resources, yet access to trained CBT-I therapists remains scarce in most health systems. Digital and guided self-help formats have been proposed to close the access gap, and the component questions raised by Saripudin and Saputri apply with equal force here: if ACT is delivered through an app or a brief primary-care consultation, which elements survive the compression, and do the acceptance processes still engage? The authors suggest that acceptability metrics become a gating criterion in stepped-care algorithms, allowing services to route patients toward the least intensive treatment they will actually complete, which maximizes population-level benefit from limited clinician time.

None of this diminishes the significance of the updated meta-analysis that prompted the correspondence. Pooling randomized controlled trials is exactly the right starting point, and the finding that ACT produces measurable benefits for insomnia patients is noteworthy on its own terms. The letter’s contribution is to insist on intellectual honesty about what the pooled estimate can and cannot support. Effect sizes derived from heterogeneous packages, without mechanism data, without acceptability measurement, and without head-to-head comparisons at defined steps of a care pathway, justify curiosity rather than clinical rollout. The distinction matters because premature scaling of an incompletely characterized therapy risks repeating the access-versus-evidence tensions that have complicated other behavioral health rollouts.

What happens next will depend on whether trialists take up the design challenges laid out in the letter. The prescriptions are concrete: pre-register component definitions, include validated process measures of psychological flexibility and acceptance, conduct formal mediation analyses, report standardized acceptability outcomes, and embed ACT within stepped-care trials that compare explicit treatment sequences rather than isolated packages. If the field responds, the result could be a genuinely personalized behavioral sleep medicine, in which a patient whose insomnia is driven by nocturnal struggle is steered toward acceptance-based work while a patient with entrenched sleep-incompatible habits receives restriction-based CBT-I first. If the field does not respond, acceptance and commitment therapy risks remaining an attractive but under-specified option, championed by enthusiasts and underused by systems. Saripudin and Saputri’s letter is, in effect, a roadmap for turning promising pooled statistics into a defensible, patient-centered treatment strategy, and it arrives at a moment when demand for better insomnia care has never been higher.

Subject of Research: Optimizing acceptance and commitment therapy for insomnia through improved trial methodology, stepped-care integration, and acceptability measurement

Article Title: Optimizing the role of acceptance and commitment therapy for insomnia: methodological challenges, stepped-care integration, and acceptability metrics

Article References: Saripudin, M., & Saputri, H. (2026). Optimizing the role of acceptance and commitment therapy for insomnia: methodological challenges, stepped-care integration, and acceptability metrics. Journal of Clinical Sleep Medicine, 22(1), Article 160. https://doi.org/10.1007/s44470-026-00184-7

Image Credits: AI Generated

DOI: 10.1007/s44470-026-00184-7

Keywords: acceptance and commitment therapy, insomnia, cognitive behavioral therapy for insomnia, stepped care, psychological flexibility, sleep medicine, meta-analysis, treatment acceptability, randomized controlled trials, behavioral sleep medicine, adherence, methodology