ADHD as a disorder of operational capacity: a buffered-state framework for sustained engagement instability

Attention-deficit/hyperactivity disorder (ADHD) is commonly conceptualized as a disorder of executive dysfunction or impaired motivation. In clinical practice, however, many individuals with ADHD describe a different core difficulty: they can initiate tasks appropriately, understand goals, and exert effort, yet struggle to remain engaged as time-on-task and internal strain accumulate. These failures are often abrupt, ego-dystonic, and strongly context-dependent, posing challenges for models based solely on static deficits or gradual depletion. Building on this phenomenology, we propose a constraint-level framework that conceptualizes ADHD as a disorder of operational capacity—the finite tolerance for sustaining stable mental engagement under cumulative cognitive and emotional demand. Within this framework, sustained engagement is modeled as a buffered state that remains stable while cumulative load is within tolerance but becomes increasingly fragile near saturation and may undergo nonlinear collapse into disengagement. We formalize this governing constraint as Operational Economy (OE)—a regulatory, not energetic, constraint principle—and describe a pre-volitional Global Switching Framework (GSF) that mediates rapid state transitions once engagement stability is exceeded. This formulation integrates and extends cognitive-energetic and state-regulation accounts while explicitly differentiating the OE/GSF framework from these predecessors by its emphasis on threshold-dependent dynamics, bounded tolerance, and asymmetric re-engagement. This framework offers a coherent account of clinical features such as intact initial performance with late-stage disengagement, pronounced time-on-task effects, and context-dependent hyperfocus. The framework generates falsifiable predictions regarding sensitivity to cumulative demand, stress-related acceleration of disengagement, pharmacological effects that preferentially extend engagement endurance rather than normalize peak executive performance, and individual differences across ADHD subtypes and comorbid presentations. These predictions are consistent with existing empirical findings on time-dependent variability in ADHD and provide a basis for future experimental validation.

Attention-deficit/hyperactivity disorder and chronic pain: a scoping review of epidemiology, clinical phenotypes, mechanisms, and treatment

IntroductionEmerging evidence suggests a potential association between attention-deficit/hyperactivity disorder (ADHD) and chronic pain; however, extant findings are dispersed across disciplines and have not yet been comprehensively synthesized. This scoping review aimed to systematically map the epidemiological evidence, clinical phenotypes, proposed neurobiological mechanisms, and reported therapeutic interventions related to comorbid ADHD and chronic pain.MethodsA comprehensive literature search was conducted in PubMed, PsycINFO, and the Cochrane Library from database inception to December 28, 2025. Human studies examining the association between ADHD (diagnosed or symptom-defined) and chronic or recurrent pain were also included. Fifty studies met the eligibility criteria, including observational studies (cross-sectional and longitudinal), case reports and series, and one interventional study.ResultsEpidemiological studies have consistently reported significant associations between ADHD symptoms or diagnoses and chronic pain in both the general population and clinical samples. Higher ADHD symptom burden was associated with greater pain severity and pain-related functional impairment. Comorbidity was observed not only in widespread pain syndromes, such as fibromyalgia, but also in site-specific conditions, including chronic low back pain, orofacial pain, and migraine. Proposed mechanisms involve dopaminergic and noradrenergic dysfunction affecting motor regulation, sensory processing, and descending pain modulation systems. Several case-based reports have described improvements in pain outcomes after ADHD-targeted pharmacotherapy. However, controlled trials remain scarce.DiscussionCurrent evidence suggests that ADHD traits may be relevant in a subset of individuals with chronic pain, particularly those with treatment-resistant presentations. Although causality and treatment efficacy remain unconfirmed, consideration of neurodevelopmental characteristics may enhance clinical assessments and inform future research on individualized mechanism-based treatment strategies.

Maintaining Emotional Boundaries as a Parent

Parents often emphasize to children the importance of respecting others’ boundaries — don’t tickle another kid if they say they don’t like it, for example. Don’t kiss someone unless they welcome it. But within the family, we can fail to notice our own difficulty setting and respecting boundaries with our children, especially emotional boundaries.

What are emotional boundaries

Emotional boundaries refer to an individual’s sense of autonomy and ability to control how they think, feel, and engage with others. Those boundaries are crossed either when you try to control someone else’s thoughts or feelings or they try to control yours.   

Difficulty setting your own and respecting others’ emotional boundaries often comes from a place of care and concern. Parents are usually concerned that their child is not going to make safe choices or are trying to protect their child from distressing emotions. But the intrusion can have a negative impact on children’s emotional development as well as parents’ mental health, especially when it’s done repeatedly. Everyone has boundaries, even parents, and it’s important for kids to learn that.  

How parents overstep their child’s emotional boundaries

Parents can inadvertently encroach on their child’s right to their own thoughts and feelings through:

  • Over-involvement in children’s academic and social life: Your child has a whole life outside the home, and it can be anxiety-provoking to trust them to manage their homework, advocate for themselves with teachers, and navigate conflicts with peers. It can alleviate your anxiety to get involved, but that can feel highly intrusive to your child. For example, if your kid feels snubbed by a friend, you might feel the urge to contact that friend’s parent to try to smooth things over. However, over-involvement in these tasks can prevent your kid from developing the skills they need to manage challenging situations successfully and can impact their confidence in their ability to cope independently.
  • Overconcern to protect your child’s safety: Fears that something negative will happen to your child are understandable, but aggressive monitoring can backfire. This can include strict control over the ingredients in your teen’s food, the information they consume online, or what activities they do. This may temporarily alleviate anxiety about the child’s health and safety but it can lead to resentment and rebellion. 
  • Ignoring or rejecting children’s requests for privacy: It is normal for children and adolescents to want more privacy as they mature, from showering alone to keeping a private diary.Unless your child engages in an activity that suggests they are being unsafe, it is important to trust your child and let them decide what to share with you.
  • Sharing private information without the child’s permission: Parents telling anecdotes about their children, much to their kids’ embarrassment, is hardly new. However, that sharing now includes photographs and videos posted on social media that is broadcast far beyond close friends.It is important to include your child in decisions about what information is shared with others (excluding, of course, medical professionals). When in doubt, consider what information you would feel comfortable with them sharing about you.
  • Telling children what is or isn’t acceptable to value, think, or feel: Many parents, in an effort to help their child feel better, say things like, “Don’t worry about that” or “You can’t think that way.” These seemingly innocuous phrases can come across as attempts to control how the child feels. We can forget that kids are real people just like adults. And if they’re mad or upset about something, they want to be able to feel those feelings, not be told that that their feelings are wrong.

How parents fail to set their own emotional boundaries

Letting kids change your own values, thoughts, and feelings can also be unhealthy. Here are some common ways in which parents fail to set their own boundaries:

  • Allowing your child’s thoughts and feelings to influence your own too much:  Your child may act like it will be the end of the world if they don’t get into the right college. If their anxiety becomes your anxiety, then it’s going to be very hard for you to encourage your kid to have fun on the weekend or to go to bed with work left undone. What they need you to do is validate their feelings but challenge those worry thoughts and help them to relax.
  • Implying that your child is responsible for how you feel:  As a parent, your child’s well-being is your priority, and your emotional state is affected by your child’s behavior. But phrases like, “You are making me crazy” or “I cannot cope with one more word from you” unintentionally suggest that the child has control over your feelings. It’s not healthy for children to feel that they are responsible for your well-being.
  • Depending on your child for emotional support: If you’re a parent under stress and you’re not getting support elsewhere, it makes sense that you’re going to vent to a child. It’s not necessarily meant to burden a kid with financial stressors or relationship drama, and the child might be a sympathetic ear. But it blurs the boundaries between the parent role and the kid role, and that often causes difficulties for the kid in accepting parental authority in other domains. If they see themselves as equals in terms of emotional support, then they might think, why can you tell me what to do?
  • Sharing age-inappropriate information: Many children want to be treated as older than they are (at least in certain ways). So they might requestinformation about finances, romantic relationships, or family stressors that are inappropriate for their age. Although it can be tempting to share, it is not helpful long-term. It may alleviate the child’s current anxiety (and stop the nagging), but it will impair their ability to respect boundaries as well as interfere with them just being a kid.
  • Difficulty saying no: If you’re exhausted, the last thing you want is an argument. One way to avoid an argument is to say yes to your kid’s requests to buy a toy, stay up 15 more minutes, or have a different dinner. If you have boundaries around what you will spend, how much sleep you need, or what you will cook, you are still a good parent. Sticking to your limits teaches your child to accept other people’s boundaries without whining or threats. 
  • Allowing your child to treat you unkindly: Many parents allow their children to treat them in ways they would never tolerate from another person. This includes calling the parent mean or profane names, hitting them, or disregarding their needs (for money, sleep, leisure time, etc.).  Allowing this kind of behavior prevents the child from learning how to respect boundaries and tolerate the emotions they experience when they face them.

Factors that contribute to boundary concerns

There are specific circumstances that can make it difficult for a parent to know where the appropriate boundaries are. They include a child’s late development, psychiatric challenges, and history of unsafe choices. For example, a child may have delays in language, executive functioning, or social or emotional skills. These things can make it challenging to determine how involved you need to be in your child’s daily life and how much independence they can handle.

  • Poor risk assessment and impulsivity: Many disorders can impact children’s ability to think clearly, regulate emotionally, and act safely. For example, a teen experiencing a manic episode may overestimate their abilities, underestimate risk, and act impulsively. Or a child with ADHD might hard to control on crowded city streets or in restaurants, so you avoid taking them out or letting them do activities on their own with friends.  
  • Lack of confidence: Anxious children may underestimate their abilities and request continued support past when they are capable of independence. For example, a socially anxious child may ask their parent to order for them at a restaurant or keep track of their homework assignments.  When a parent accommodates these requests, it confirms their belief that they still need help.
  • Executive functioning deficits: Children who struggle with executive functioning may need more scaffolding to complete daily self-care tasks than other kids their age. This can look like parents providing frequent reminders of assignments, events, or even hygiene tasks — as well as cleaning their room for them long past when an child with ADHD should be doing it themselves. Consider how you can scaffold the skills (packing their bookbag!) without doing tasks for them, and gradually remove the supports over time.
  • History of not successfully navigating tasks: A child’s history of poorly handling a responsibility (safe use of technology, completion of homework, brushing their teeth) often reduces parents’ confidence in the child’s abilities and increases their inclination to step in. Although extra supervision and support may be needed initially, it is important to reassess your child’s abilities over time as they can learn and grow if you let them!

How to get better at boundaries

Once you have recognized the challenges in respecting your child’s boundaries and protecting your own, the next step is to figure out what those boundaries are.

  • Identify your boundaries: What things are most important to support your child’s growing independence and sense of autonomy? What boundaries do you need to set to protect your own mental health? Consider what level of involvement you want to have in their academics, friendships, emotion regulation, and appearance and what you want to disclose to them about your own relationship, emotions, or work.  
  • Practice setting these boundaries: It is much easier to set a boundary when you are not forced to make the choice with a child’s puppy dog eyes looking at you. Rehearsing how you will say no, decline to share certain information, or respond to an anxiety-provoking situation can prepare you to respond more effectively and in line with your values in a moment of conflict.
  • Share your reasons for boundaries: Children can be quick to interpret lack of boundaries as “more caring,” but being consistent in language around why boundaries are being set can help prevent this. When setting a boundary, it is helpful to couch it in care. For example, “I care about you enjoying your childhood, so I do not feel comfortable sharing with you about our family’s finances.”

When kids want more independence than you are sure they are ready to handle, identifying steps toward their goal can be effective. Giving them opportunities to show maturity, with success at one step leading to more responsibility, can help you trust your child with greater independence. What can your kids show you that will help you feel confident in their ability to manage their emotions themselves or make well thought-out decisions?

Kids also need to recognize that they sometimes overestimate their own abilities, that there are times they have not assessed risk accurately and still need their parents. It is important to teach your child that you should be alerted if they are experiencing something that is unsafe or concerning (such as a friend talking about suicide or sharing an inappropriate photo). Discussions with your kid can sort out how to work toward new milestones and help everybody feel confident that they have the skills to do it.

Modeling a healthy respect for boundaries will set your child up to establish their own and respect others’ boundaries throughout their life.

Frequently Asked Questions

What are emotional boundaries between parents and children?

Emotional boundaries are the limits that protect each person’s right to their own thoughts, feelings, values, and decisions. In families, healthy boundaries allow children to develop independence while helping parents avoid taking responsibility for emotions or choices that belong to their child.

Why are emotional boundaries important in parenting?

Healthy emotional boundaries support children’s confidence, autonomy, and ability to solve problems on their own. They also protect parents’ well-being by preventing them from becoming overly responsible for their child’s feelings, worries, or decisions.

What are signs a parent is overstepping a child’s emotional boundaries?

Common signs include getting overly involved in a child’s friendships or school life, refusing age-appropriate privacy, sharing personal information without permission, or telling a child what they should think or feel. While these behaviors often come from a place of love and concern, they can undermine a child’s confidence and independence.

How can parents determine appropriate emotional boundaries?

Parents can start by considering where their child is developmentally and what level of support versus independence is appropriate. A good guideline is to provide enough structure to keep children safe while gradually giving them more responsibility and privacy as they demonstrate readiness.

The post Maintaining Emotional Boundaries as a Parent appeared first on Child Mind Institute.

Prevalence of pharmacologically treated attention deficit hyperactivity disorder in children, adolescents, and adults: systematic review and meta-analysis

IntroductionAttention deficit hyperactivity disorder (ADHD) is one of the most common neurodevelopmental paediatric disorders and persists into adulthood, although it is frequently underdiagnosed and underrecognized in adult populations. In this context, the prevalence of pharmacologically treated individuals diagnosed with ADHD represents an important quality indicator for ADHD management.AimTo estimate the pooled prevalence of pharmacologically treated individuals with ADHD in different age groups in Europe and worldwide.MethodsA comprehensive search of PubMed/MEDLINE was conducted to identify relevant articles published up to October 4, 2024. The present systematic review and meta-analysis examined ADHD prevalence using clinically confirmed diagnoses and treatment data from official records. The exclusion criteria included studies that lacked clinical confirmation of ADHD and/or relied exclusively on parental reports for diagnostic or medication information. The prevalence of pharmacologically treated individuals with ADHD was calculated as a percentage, with a 95% confidence interval (CI). A meta-analysis was performed in R using a random-effects model. Heterogeneity was calculated using I². Prediction intervals were additionally computed to reflect the expected range of prevalence in future studies. Risk of bias was assessed for all included studies using a standardized, previously published methodology. The study was prospectively registered in PROSPERO (CRD42020200220) and adhered to the PRISMA guidelines for systematic review and meta-analysis (2020).ResultsThe systematic review identified 13 studies (12 studies included in the meta-analysis) with substantial variation in age-specific reporting. The pooled prevalence of pharmacologically treated ADHD was 73.4% (95% CI: 63.4–81.5), with extremely high between-study heterogeneity and wide 95% prediction interval (29.6%–94.5%), reflecting substantial variation across settings. The pooled prevalence estimate should be interpreted with caution due to substantial between-study heterogeneity and is not intended for direct clinical inference. Geographic analyses revealed no significant variation across countries. Sex-stratified analyses showed no significant difference between males and females, although point estimates were slightly higher in males.ConclusionThe prevalence of pharmacological treatment among individuals with ADHD appears to vary across age groups and settings Overall, findings indicate substantial variation in pharmacological treatment of ADHD by age, with consistently high heterogeneity limiting the precision of pooled estimates.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/, identifier CRD42020200220.

Treating ADHD With Methylphenidate (Ritalin, Concerta)

Methylphenidate is a stimulant medication used to treat symptoms of ADHD. It helps the brain regulate attention, focus, and impulsive behaviors.

It’s one of the two stimulants widely used in ADHD medications. Methylphenidate is the active ingredient in Ritalin and Concerta, among others. The other commonly used stimulant, amphetamine, is the active ingredient in Adderall and Vyvanse, among others. Both stimulants work by increasing levels of dopamine and norepinephrine, chemicals in the brain that control attention, focus, and impulsivity. If a child doesn’t do well on the first stimulant medication they try, they may respond better to a different formulation of that type or the other type of stimulant.

How is methylphenidate different from amphetamine?

Methylphenidate is somewhat less powerful than amphetamine and tends to have milder side effects.

If your child is under 12 and has just been diagnosed with ADHD, a doctor is likely to prescribe a methylphenidate medication first, to see how well the medication reduces their ADHD symptoms, and whether the side effects are problematic.

Methylphenidate is also many doctors’ first choice for younger children because it has been used to treat ADHD much longer than amphetamine. Ritalin (methylphenidate-based) was FDA approved in 1955, while Adderall (amphetamine-based) wasn’t approved until 1996. In countries outside the United States, amphetamine-based ADHD medications are less widely approved than those based on methylphenidate.

How methylphenidate works vs amphetamine

The two stimulants target the same brain chemicals but work slightly differently, says Paul Mitrani, MD, PhD, a child and adolescent psychiatrist at the Child Mind Institute. Methylphenidate increases the levels of dopamine and norepinephrine by blocking what’s called reuptake — the process by which nerve cells reabsorb these chemicals after they’ve been released. As Dr. Mitrani describes it, methylphenidate “enhances” the norepinephrine and dopamine the brain naturally releases by making the chemicals stay around longer. It boosts the stimulation the brain is already getting from whatever activity the child is engaged in.

Amphetamine, on the other hand, not only blocks reuptake but stimulates the release of more dopamine and norepinephrine, which is why it’s considered stronger. “Adding stimulation with amphetamine sometimes helps,” he notes. “But sometimes that added stimulation is too much, and it increases side effects the child experiences.”

Kids vary in how they respond to methylphenidate vs amphetamine

There is individual variation in how children respond to the two stimulants. So if methylphenidate doesn’t give the desired symptom relief or produces problematic side effects, it’s recommended practice to try amphetamine, or vice versa. Research shows that 70 percent of children with ADHD respond to a trial of methylphenidate. More than 90 percent will have a beneficial response to one of the stimulants if both methylphenidate and amphetamine are tried. Studies also show that approximately 41 percent respond equally well to both types of stimulant.

Children can also vary in their response to different formulations of the same stimulant, which affect the rate at which the medication goes into the bloodstream.  For instance, a short-acting form of Ritalin will kick in quickly and last for 3-4 hours, while Concerta, a delayed-release formula, lasts as long as 10-12 hours. It’s very common for kids to try several before finding the best fit.

What are the side effects of stimulant medications?

Methylphenidate and amphetamine have the same side effects, though they may be less intense with the former.

Appetite suppression

The most common side effect of stimulants is appetite suppression. It can be especially concerning with long-acting forms of the medication, which are often preferred to get better coverage through the school day. Kids who take a long-acting stimulant in the morning tend to lose their appetite for lunch and may not be interested in eating until after dinnertime.

When this is a problem, Dr. Mitrani notes that taking a shorter-acting form of the medication can help. “For instance, Concerta is a methylphenidate medication that lasts for a long time and can suppress appetite for 10–12 hours.” An alternative might be a medication that lasts for 6–8 hours, such as Metadate CD or Ritalin LA. Some children with more pronounced problems with appetite will do better on a short-acting dose in the morning and then another after lunch, he adds, since it gives them a break during the day where they can eat better.

Sleep issues

Kids who take stimulant medication can have trouble falling asleep. This can happen when a long-acting medication or an afternoon dose of a short-acting medication wears off and they get restless or hyperactive around bedtime. Difficulty falling asleep can get better after a few weeks, but if it doesn’t, it may be helpful to change either the timing or the type of the medication that is given. It’s also important to explore whether there are other contributors to sleep challenges, such as worry, screen time too close to bedtime, or lack of a consistent evening routine that helps kids calm down.

Irritability

Stimulant medications can generate agitation and irritability, which can be especially problematic in kids who are already anxious. For children with anxiety, this can be another reason to start treatment with methylphenidate, because amphetamines can feel more activating.

But Dr. Mitrani notes that treating ADHD can also reduce anxiety: “Some kids are so stressed about school — because they can’t pay attention or arealways getting in trouble — that when you treat the ADHD, they are better able to manage the demands of school and become less anxious.”

That reduction in school anxiety can also affect what happens when they get home from school. “When there is anxiety, it’s like kids are holding it together at school, and then they come home after a stressful day and just let it out,” he says. “So if the school day is less stressful, you may also see that come down at the end of the day.”

Mood changes

Some children report that stimulant medications seem to dull their personality. Dr. Mitrani suggests that this may be connected to the medication stimulating the prefrontal cortex, the part of the brain that not only manages attention and focus, but also helps regulate emotions and impulse control in other brain areas. “Enhanced control of the emotional part of the brain can cause this feeling of dullness,” he notes. “Some people will even say they feel depressed, that they’re just not like themselves because they don’t have the same energy or personality.”

If this happens to a child on methylphenidate, Dr. Mitrani will recommend trying an amphetamine or a non-stimulant medication.

Rebound effects

Some families report that their child is irritable or emotional after school or at the end of the day, when the stimulant medication is wearing off. Dr. Mitrani notes that this can coincide with the child being hungry after missing lunch. It can also be connected to the medication level dropping too quickly, and strategies that create a more gradual decrease may help take it away. For example, he might suggest adding a small dose of  short-acting form of the stimulant a half hour before the morning medication wears off.

Starting children on methylphenidate

Dr. Mitrani usually starts a child on a short-acting form of methylphenidate for two reasons: as a quick test to see if the child will experience side effects and to have an opportunity to try it twice in a day, to have more chances to assess for positive changes.

He recommends starting the medication on a weekend or a break from school and giving the child some tasks that are challenging for them because of their ADHD, like reading or something else that requires concentration, such as cleaning their room or doing household chores. “After lunch you want to try it again, to have another time point to check on. Because if you only give one dose of the medication, you don’t know if the child’s behavior was a result of the medication or some other factor. The more data points that we have, or more trials, the more information we get.”

He recommends keeping the child on short-acting doses for at least several days before trying a longer-acting formula.

Starting children on a low dose

Practice guidelines for psychiatrists recommend starting children on a low dose to assess any side effects the child might experience and gradually increasing it over 1-2 weeks with careful monitoring of response until you reach the minimum dose that will give the best symptom relief.

There is a great deal of variation in how children respond to these medications, so starting with an “average” effective dose, even adjusted by body weight, would be under-medicating some kids and overmedicating others.

For instance, for a 6- or 7-year-old child, a common starting dose of a short-acting medication might be about 2.5 mg, going up to 5 mg if more is needed for symptom relief and side effects are not an issue, Dr. Mitrani says. 

Liquid versions of either stimulant have an advantage when it comes to getting exactly the right dose, he notes: “You can do, 1 milliliter, 1.5, 1.6, depending on the syringe.”

Long-acting formulations that come in capsules can be especially frustrating, he adds — since they come in set doses and can’t be opened and divided effectively, because the beads inside are made to be triggered at different time periods.

Trying different formulations

Dr. Mitrani stresses that small differences in the formulation of a medication can make a difference in a child’s reaction.

For instance, Focalin (dexmethylphenidate) is a refined form of methylphenidate. Standard methylphenidate medications contain two mirror-image forms, or isomers, but most of the benefit comes from one of them. Focalin contains only this more active isomer. For some children, it works better, causes fewer side effects, or feels smoother.

He also notes that variations in the release patterns among long-acting formulations can affect a child’s experience. “Take Concerta, which has a unique mechanism for the extended release,” he explains. “There are three phases: a really immediate phase, then a regular Ritalin kind of phase and, then a slow extrusion of the remaining methylphenidate throughout the day that helps it last as long as 12 hours.”

By contrast, he describes Ritalin LA, which tends to last for 6-8 hours, as “50-50” — 50 percent of the dose is immediate released and the other half is delayed release. Other formulations are “40-60” or “30-70.” “These subtle differences can result in some kids responding better to one than the other, while other kids can do well on any of them.”

So even within the methylphenidate group, there may be reason to try a child on number of different formulations to get the best fit. And, of course, other reasons for trying different versions are limits on what insurance covers —which can change suddenly — and what’s available because of shortages. “And that can be really frustrating for families,” he says. “What I hear is, ‘My child was on Concerta or on Metadate CD and they made me switch to this one and now my kid’s not doing as well.’ “


When families cannot get a medication that has been working, finding another medication that’s available, that’s effective, and that insurance will approve can be a lot of hoops to jump through, he adds.

The post Treating ADHD With Methylphenidate (Ritalin, Concerta) appeared first on Child Mind Institute.

Subjective sleepiness and objective sleep propensity in adults with attention-deficit/hyperactivity disorder referred for multiple sleep latency testing

IntroductionAdults with attention-deficit/hyperactivity disorder (ADHD) often report excessive daytime sleepiness, but the relationship between subjective sleepiness and objective sleep propensity remains unclear. We examined this relationship in adults referred for Multiple Sleep Latency Test (MSLT) evaluation, using a clinical comparison group with excessive daytime sleepiness (EDS) but without ADHD.MethodsIn this retrospective cross-sectional study, we analyzed medical records of 130 adults aged 18 years or older who underwent MSLT between January and December 2021, including 68 adults in the ADHD group and 62 in the EDS-only group. Subjective sleepiness was assessed by the Epworth Sleepiness Scale (ESS) and objective sleep propensity by mean MSLT sleep latency, with MSLT positivity defined as mean sleep latency ≤ 480 s. Associations between ESS scores and mean sleep latency were assessed within each group, and correlation coefficients were compared between groups using Fisher’s r-to-z transformation.ResultsESS scores did not differ significantly between groups, with median scores of 14.0 in the ADHD group and 13.0 in the EDS-only group. In contrast, objective sleep propensity differed significantly: median mean sleep latency was longer in the ADHD group than in the EDS-only group (432.0 s vs 322.0 s, p = 0.008), and MSLT positivity was less frequent in the ADHD group (61.8% vs 87.1%, p = 0.001). Within the ADHD group, ESS scores were not significantly correlated with mean sleep latency, including among MSLT-positive cases. A significant inverse correlation was observed in the MSLT-positive EDS-only subgroup, although formal comparison of correlation coefficients did not demonstrate a statistically significant between-group difference in the ESS–MSLT relationship. SOREMP frequencies were numerically higher in the EDS-only group but did not differ significantly between groups.DiscussionThese findings suggest that subjective sleepiness complaints and objective sleep propensity may not closely align in adults with ADHD referred for sleep evaluation, and support the need for integrated psychiatric and sleep-medicine assessment when such patients present with excessive daytime sleepiness.