The dataset behind the study is unusually large for this field. The researchers analysed 1,434 dream reports and 1,619 mind-wandering reports collected from 176 individuals. Rather than reading each narrative and coding it by hand with subjective categories, the team converted the language itself into networks. In this approach, each word in a report becomes a node, and the relationships between words become edges. Once a report is transformed into a graph, the entire toolkit of network science becomes available: measures of how tightly words cluster together, how easily information can travel across the network, how often words repeat, and how central particular words are to the overall structure of the text.

The first major finding concerns the global architecture of the two kinds of reports. Dream reports turned out to have a more complex structure than mind-wandering reports, displaying more word repetitions, more local cliques, tightly interconnected clusters of words, and greater global integration. The authors describe this pattern as resembling a small-world structure, a configuration familiar from studies of brain networks and social networks, in which dense local clusters are linked by shorter paths across the whole system. Mind-wandering reports, by contrast, contained fewer word repetitions and were more verbose, with distinct transition points marking shifts in the flow of the narrative.

Why would dreams and daydreams leave such different structural traces in language? The researchers point to a plausible cognitive explanation rooted in memory. Dream reports depend on recall over longer periods of time, because a dream must be held in mind and then reconstructed in words after waking. That reconstruction process appears to encourage repetition of key words and a more integrated, clustered organization of the narrative. Mind wandering, sampled closer to the moment of experience, produces longer, more lexically varied accounts in which the speaker moves through topics with fewer loops back to earlier material. The graph metrics capture this difference objectively, without any researcher needing to judge what a dream is about.

Perhaps the most striking result is that the network structure of these reports is not generic. By capitalising on a repeated measures design, in which the same individuals contributed multiple reports across both states, the team found that the structure of dream and mind-wandering narratives contains individual-specific information. In other words, the way a particular person connects words when describing their inner life is stable enough to distinguish them from other people. This suggests that narrative structure reflects enduring characteristics of how an individual’s mind organizes experience, rather than being merely a by-product of the topic that happened to drift through consciousness on a given day.

The study also uncovered a link between language structure and mental health. Word centrality, which corresponds to lower lexical diversity, meaning that a smaller set of words dominates the network of a report, was predictive of symptoms of depression and anxiety. Notably, the association was state-specific: centrality in dream reports predicted depressive symptoms, while centrality in mind-wandering reports predicted anxiety symptoms. This dissociation hints that different forms of inner experience may carry different kinds of clinical information, and that the architecture of spontaneous thought could serve as a window onto distinct dimensions of psychological distress.

Technically, the approach has significant advantages over traditional content analysis. Classic dream research often relies on trained judges rating reports on scales such as bizarreness, emotion, or thematic content, which is labour-intensive and vulnerable to inter-rater variability. Graph-theoretical analysis, once implemented, can process large volumes of naturalistic text cheaply and consistently. The authors emphasise that the method seems promising for cost-effective analyses of large, naturally occurring qualitative datasets, a category that includes not only dream and mind-wandering reports but potentially other forms of unstructured self-narration collected in clinics, sleep laboratories, or experience-sampling studies.

The work also speaks to a long-standing debate in consciousness science. Dreams and mind wandering are both examples of spontaneous, stimulus-independent thought, yet they arise in radically different states: one during sleep, the other during wakefulness. By showing that the two can be quantitatively differentiated using nothing more than the structure of the language used to report them, the study provides a new empirical handle on how the state of consciousness shapes the organization of thought. The small-world-like structure of dream narratives, with its repetitions and integrated clusters, may reflect how sleep-dependent memory processes and the absence of external input sculpt the flow of experience, while the more verbose, transition-rich structure of waking mind wandering may mirror the restless, forward-moving character of unguided daytime thought.

There are, of course, caveats. The measures capture the structure of reports, not the experiences themselves, and reporting is always filtered through memory, language ability, and the demands of the moment. The clinical findings are predictive associations rather than diagnostic tools, and the authors note that the article was shared early as a citable, peer-reviewed accepted version subject to further editorial refinement. Even so, the implications are considerable. If the architecture of a person’s dream narratives is stable, measurable, and sensitive to their mental state, then something as ordinary as telling a researcher about last night’s dream could, with the right mathematics, reveal enduring features of the mind that produced it. The study, supported by funders including the Alfred Kordelin Foundation, the Emil Aaltonen Foundation, the Finnish Cultural Foundation, the Bial Foundation, the Cambridge ESRC Impact Acceleration, and the Australian Research Council, was jointly supervised by Natália Bezerra Mota and Tristan Bekinschtein, and brings together teams from Cambridge, Stanford, Turku, Skövde, Monash, Queen Mary University of London, and the Federal University of Rio de Janeiro.

What makes the research resonate beyond the laboratory is its simplicity and reach. The raw material is free: people describing their inner lives in their own words. The analysis requires no brain scanners, no electrodes, and no invasive procedures, only computational tools that turn stories into networks and networks into numbers. As large language datasets become ever easier to collect through smartphones and experience-sampling apps, methods like this one could transform how psychologists study spontaneous thought, how clinicians track symptoms over time, and how consciousness researchers compare states of mind that have always been, until now, notoriously difficult to measure. The mind’s private narratives, it turns out, have a shape, and that shape can be charted.

Subject of Research: Graph-theoretical analysis of the linguistic structure of dream and mind-wandering reports and its links to individual differences and mental health symptoms

Article Title: A graph theory approach to chart the architecture of dream and mind-wandering reports

Article References: Coppola, P., Sikka, P., Valli, K., Tuominen, J., Revonsuo, A., Loukola, V., Bernstein, R., Strid, N., Kirberg, M., Ezquerro-Nassar, A., Windt, J., Noreika, V., Mota, N. B., & Bekinschtein, T. A. (2026). A graph theory approach to chart the architecture of dream and mind-wandering reports. Communications Psychology, 4(1), Article 135. https://doi.org/10.1038/s44271-026-00509-5

Image Credits: AI Generated

DOI: 10.1038/s44271-026-00509-5

Keywords: graph theory, dreams, mind wandering, consciousness, network analysis, language, depression, anxiety, small-world networks, lexical diversity, mental health, spontaneous thought

The argument rests on a striking mismatch between how clinicians are trained and how most of the world actually experiences sleep. Contemporary sleep medicine remains overwhelmingly grounded in biomedical models that treat sleep as a physiological process to be measured and corrected. Yet the authors point out that dreams, nightmares, sleep paralysis, and nocturnal visions have historically been interpreted through spiritual, moral, existential, and cultural frameworks worldwide. These interpretations are not relics of a distant past. They continue to shape how billions of people understand what happens to them at night, how distressed they become when sleep goes wrong, and whether they ever seek help from a physician at all.

The scale of the phenomenon is difficult to dismiss. According to data cited in the editorial, approximately 75.8 percent of the world’s population is affiliated with a religious tradition, and even among the nearly one-quarter of people who are religiously unaffiliated, many still identify as spiritual or hold spiritual beliefs and practices. Sleep-related spiritual experiences, far from being rare curiosities, appear to be commonplace. In the United States, 53 percent of adults report dreams or other experiences involving deceased loved ones. In Brazil, a nationwide study found that 70 percent of respondents reported at least one precognitive dream. Out-of-body experiences, including those occurring during sleep or in the fragile transitions between sleep and wakefulness, have been reported by up to 20 percent of the population. For many people, these experiences are meaningful or even comforting. But when individuals lack cultural, spiritual, or social frameworks through which to interpret them, the same experiences can become sources of significant distress that drive them into clinics and sleep labs.

Mainstream psychiatry has already begun to respond. In 2025, the American Psychiatric Association expanded the DSM-5-TR code Z65.8, formerly labeled Religious or Spiritual Problem, to Moral, Religious, or Spiritual Problem. The change formally recognizes that moral and spiritual distress or conflict can be clinically significant and worthy of clinical attention, without pathologizing them as psychiatric disorders. The authors argue that this shift is directly relevant to sleep medicine, because a growing body of evidence links trauma exposure, moral injury, and spiritual distress with nightmares, hyperarousal, and insomnia symptoms. A veteran wrestling with moral injury, for example, may present to a sleep clinic with severe nightmares and fragmented sleep, while the underlying spiritual wound remains unexamined and untreated.

Religion and spirituality are also increasingly understood as determinants of sleep health in their own right. The editorial reviews studies reporting associations between religious service attendance, positive religious coping, and spiritual well-being on one hand, and better sleep quality and longer sleep duration on the other. Conversely, religious struggle, spiritual distress, religious doubt, and guilt have been linked to poorer sleep outcomes. The proposed mechanisms are not vague appeals to the ineffable. The authors describe plausible pathways including enhanced coping resources, greater resilience to stress, reduced neural reactivity to negative emotional stimuli, and neurobiological correlates associated with lower risk of depression and improved emotional regulation. In other words, the way people find meaning, hope, and community may leave measurable traces in the stress physiology and emotional regulation systems that govern sleep.

Cross-cultural research makes the case even more vivid. Among Māori communities in Aotearoa, New Zealand, qualitative research conceptualizes sleep as a spiritually significant state in which the wairua, or spirit, awakens, journeys, learns, and provides guidance for waking life. In several African cultural traditions, dreams may be interpreted as sources of guidance, prophecy, or spiritual influence, shaping how sleep disturbances are understood. Among Yoruba communities in Nigeria, nightmares and dreams may be interpreted as manifestations of witchcraft. The authors emphasize that such beliefs are not confined to any single population; they represent a common way that human beings make meaning of sleep. The clinical risk arises when experiences such as sleep paralysis, sensed presence, or vivid dream encounters are interpreted outside their cultural and spiritual context, leading to unnecessary pathologization or stigma.

What would spiritually sensitive sleep care actually look like in practice? The authors are careful to draw boundaries. Integrating spirituality into sleep medicine does not require clinicians to endorse religious beliefs, nor does it involve pastoral counseling or proselytizing. Instead, it involves recognizing when existential, spiritual, or cultural frameworks meaningfully shape a patient’s sleep experiences, distress, coping, and treatment engagement. One practical tool is the spiritual history, a brief evaluation of a patient’s spiritual needs during the clinical encounter, which can surface concerns relevant to sleep health and guide appropriate follow-up and referral. Educational initiatives such as the Interprofessional Spiritual Care Education Curriculum, known as ISPEC, already provide clinicians with training and competencies to address patients’ spiritual needs in clinical settings, and the editorial suggests such frameworks could extend into sleep medicine training.

Institutional models already exist. The Veterans Affairs health system in the United States has integrated spiritual care through interdisciplinary teams that include chaplains, offering support grounded in deep listening, presence, and person-centered care. Related initiatives, such as military spiritual fitness programs, reflect growing institutional recognition that meaning, values, and purpose are components of resilience, well-being, and readiness. Moreover, many patients actively want to discuss spiritual concerns with their clinicians, a preference that current sleep medicine practice rarely accommodates. On the therapeutic side, randomized clinical trials have demonstrated the efficacy of integrating spiritual practices into cognitive-behavioral interventions, suggesting a natural application for behavioral sleep medicine, where cognitive-behavioral therapy for insomnia already stands as the first-line treatment.

The editorial arrives at a moment when medicine more broadly is pivoting toward precision and person-centered care. The National Center for Complementary and Integrative Health has championed Whole Person Health, a biopsychosocial-spiritual framework that recognizes physical, mental, social, and spiritual dimensions of health as interconnected and collectively capable of shaping outcomes relevant to sleep. The authors frame their message as a call to action: greater attention to the influence of religion and spirituality on the practice of sleep medicine could strengthen the therapeutic alliance, improve culturally and spiritually responsive care, and advance more holistic approaches to sleep health. The work was supported in part by the Intramural Research Program of the National Institutes of Health, and the authors note that the findings and conclusions are their own and do not necessarily reflect the views of the NIH.

For a field built on actigraphy, CPAP machines, and sleep diaries, the proposal may seem like an unlikely revolution. But the underlying logic is pragmatic rather than mystical. If three out of four people on Earth belong to a religious tradition, if half of American adults dream of deceased loved ones, and if spiritual distress is now a recognized diagnostic category linked to nightmares and insomnia, then a sleep medicine that ignores these realities is missing information that shapes diagnosis, communication, and treatment adherence. The editorial does not ask clinicians to become theologians. It asks them to ask better questions, to listen for the frameworks through which patients already understand their nights, and to treat the sleeping person not merely as a nervous system to be regulated, but as a whole human being for whom sleep may carry meanings that science is only beginning to measure.

Subject of Research: Integrating spirituality and religion into whole-person, person-centered sleep medicine

Article Title: The need to integrate spirituality into sleep medicine as a dimension of whole-person, person-centered care

Article References: Singh, R., Puchalski, C. M., Moreira-Almeida, A., Merry, B., Rosmarin, D. H., Koenig, H. G., & Jackson, C. L. (2026). The need to integrate spirituality into sleep medicine as a dimension of whole-person, person-centered care. Journal of Clinical Sleep Medicine, 22(1), Article 135. https://doi.org/10.1007/s44470-026-00137-0

Image Credits: AI Generated

DOI: 10.1007/s44470-026-00137-0

Keywords: sleep medicine, spirituality, religion, whole-person care, dreams, sleep paralysis, moral injury, insomnia, spiritual care, DSM-5-TR, cultural psychiatry, person-centered care