The research team, led by Yasuhiro Ogawa of Morinomiya University of Medical Sciences in Osaka, analyzed questionnaire data from 399 health profession students in Japan. Rather than relying on formal clinical diagnoses, the investigators classified participants into four groups based on established screening thresholds: a typical group, a group with ASD traits only, a group with ADHD traits only, and a group with co-occurring ASD and ADHD traits. This trait-based approach allowed the researchers to capture students whose neurodevelopmental characteristics might otherwise go unrecognized in university settings, where many individuals with mild traits never receive a diagnosis.

Three well-validated instruments formed the backbone of the measurement strategy. Sleep quality was assessed with the Pittsburgh Sleep Quality Index, a widely used self-report tool that evaluates dimensions such as sleep duration, sleep latency, disturbances, and daytime dysfunction. Psychological distress and general mental health were measured with the 12-item General Health Questionnaire, a screening instrument sensitive to recent changes in mood, anxiety, and social functioning. Problematic internet use was quantified with the Internet Addiction Test, which probes the degree to which online activity interferes with daily life, relationships, and self-control. Participants also reported their age and sex, which were included as covariates in all analyses.

The statistical design was deliberately conservative. The researchers used multivariate and univariate general linear models, a framework that allows several related outcomes to be tested simultaneously while adjusting for confounding variables. Their central question was whether the trait-defined groups differed in the combined outcome of sleep quality and mental health, and if so, whether those differences survived once the Internet Addiction Test score was added to the model. They also tested for an interaction between group membership and internet use severity, asking whether the relationship between internet problems and poor outcomes varied depending on a student’s neurodevelopmental profile.

The results were striking. The four groups differed significantly in the combined sleep and mental health outcome, and crucially, this multivariate effect remained significant after problematic internet use severity entered the model. No group-by-internet-use interaction was detected, meaning that the burden carried by students with ASD and ADHD traits was not simply an amplified version of the harm associated with excessive internet use. In adjusted comparisons, the co-occurring ASD-ADHD group fared worst of all, exhibiting the poorest sleep quality and the poorest mental health outcomes relative to both the typical group and the single-trait groups.

This pattern carries important theoretical weight. ASD and ADHD frequently co-occur, with shared genetic and neurocognitive underpinnings, and individuals carrying both sets of traits often face compounded challenges: sensory sensitivities and social communication differences from the autism side, alongside impulsivity, inattention, and executive function difficulties from the ADHD side. Sleep disruption is a well-documented feature of both conditions, involving atypical circadian regulation, heightened pre-sleep arousal, and difficulties winding down. The present findings extend this literature by demonstrating that in a high-achieving student population, these trait-related burdens are not reducible to lifestyle factors such as late-night screen time.

Problematic internet use has become a default explanation for student sleep and mental health problems, and device-focused interventions, from digital detox campaigns to app timers, have proliferated accordingly. The Japanese data complicate that narrative. If internet overuse were the primary driver of the observed differences, adjusting for its severity should have substantially attenuated the group effects. Instead, the effects persisted essentially intact, indicating that problematic internet use alone is unlikely to fully account for the poorer sleep and mental health seen in students with ASD and ADHD traits. Internet use may still contribute to the overall burden, but it appears to sit alongside, rather than beneath, neurodevelopmental vulnerability.

The choice of population matters as well. Health profession students face demanding curricula, clinical placements, and high-stakes examinations, conditions that strain anyone’s sleep and coping resources. For students with ASD or ADHD traits, these pressures arrive on top of neurodevelopmental differences in sensory processing, organization, and emotional regulation. The fact that the co-occurring group showed the worst outcomes suggests a dose-like relationship between trait burden and impairment, consistent with the idea that overlapping traits interact rather than merely add together. For faculties of medicine, nursing, rehabilitation, and allied health, this points to a student population whose needs may be systematically underestimated.

The authors are careful about the study’s limits. The design is cross-sectional, so it cannot establish causal direction; it is possible, for example, that poor sleep exacerbates trait-related difficulties, or that distress drives more time online, or both. The data come from self-report questionnaires collected in an anonymous survey, and the sample was drawn from health profession programs in Japan, which may limit generalizability to other student populations and cultural contexts. Classification relied on screening thresholds rather than clinical diagnoses, so the groups represent trait profiles rather than confirmed diagnostic categories. The study was approved by the Ethics Committee of Morinomiya University of Medical Sciences and conducted in accordance with the Declaration of Helsinki, with electronic informed consent obtained from all participants.

Even with those caveats, the practical implications are clear. The researchers argue that student support should extend beyond device-focused interventions to include neurodevelopmentally informed accommodations and targeted sleep and mental health care. In concrete terms, that could mean flexible scheduling and quiet study environments for students with sensory sensitivities, executive function coaching for those with attentional difficulties, and sleep interventions tailored to the circadian and arousal profiles associated with ASD and ADHD. For the growing number of universities screening for problematic internet use, the message is that a high internet addiction score may be a signal worth investigating, but it is not necessarily the root cause. Understanding who the student is, not just what the student does online, may be the key to protecting both their sleep and their mental health during some of the most demanding years of their training.

Subject of Research: Associations between co-occurring autism spectrum disorder and ADHD traits and sleep quality and mental health among health profession students

Article Title: Co-occurring autism spectrum disorder and attention deficit hyperactivity disorder traits are associated with poorer sleep and mental health beyond problematic internet use among health profession students: a cross-sectional analysis

Article References: Ogawa, Y., Tanaka, H., Haga, D., Higashi, Y., Yokota, S., & Tano, K. (2026). Co-occurring autism spectrum disorder and attention deficit hyperactivity disorder traits are associated with poorer sleep and mental health beyond problematic internet use among health profession students: a cross-sectional analysis. BMC Psychology. https://doi.org/10.1186/s40359-026-05694-w

Image Credits: AI Generated

DOI: 10.1186/s40359-026-05694-w

Keywords: autism spectrum disorder, ADHD, sleep quality, mental health, problematic internet use, health profession students, psychological distress, cross-sectional study, neurodevelopmental traits, Pittsburgh Sleep Quality Index, Internet Addiction Test, student support