Journal of Attention Disorders

Prior work reports a relative age effect (RAE), in which children are more likely to be diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD) if they are relatively younger than their classmates. Yet work reporting a RAE in ADHD diagnosis has analyzed relatively dated samples, has not examined moderation across sociodemographic characteristics, and has largely not examined the RAE in longitudinal analyses. We examined whether entering kindergarten as a relatively younger student increased the likelihood being diagnosed with ADHD across elementary school. We also examined moderation by race and ethnicity, biological sex, socioeconomic status, and home language.

We analyzed data from the Early Childhood Longitudinal Study–Kindergarten Cohort (ECLS-K: 2011; N = 11,410), a nationally representative cohort. Logistic regression models estimated relations between children’s relative age and both grade-specific and cumulative ADHD diagnoses during elementary school. Discrete-time event history logit regression models examined the timing of ADHD diagnosis from kindergarten through fifth grade. Interaction terms assessed moderation by sociodemographic characteristics.

We generally failed to observe evidence of a RAE, either cumulatively or within specific grades. Discrete-time event models indicated no significant relations between relative age and timing of ADHD diagnosis. Moderation analyses identified isolated interactions, indicating the possibility of a specific RAE for Black children and those from non-English-speaking homes in select grades. However, these predicted effects were not consistently observed and did not survive correction for multiple comparisons.

In contrast to prior work analyzing older datasets, we failed to observe a RAE in U.S. elementary schools. Our finding suggest that relatively younger children attending U.S. elementary schools are not at increased likelihood for ADHD diagnosis.

Children with attention deficit hyperactivity disorder (ADHD) are vulnerable to the psychological impact of traumatic events due to inherent difficulties in emotion regulation and executive functioning. This study examines the predictive roles of attachment styles and family functioning on depressive, anxiety, and posttraumatic stress disorder (PTSD) symptoms in children with ADHD following the 2023 Türkiye earthquakes.

A longitudinal design was employed with 124 children diagnosed with ADHD, assessed at 3 months (T1) and 12 months (T2) after the earthquakes. Attachment styles were evaluated using the Three-Dimensional Attachment Styles Scale, and family functioning was assessed via the Family Assessment Device. Psychological symptoms were measured using the Children’s Depression Inventory, State-Trait Anxiety Inventory, and Children’s Revised Impact of Event Scale-13. Hierarchical multiple regression analyses were conducted to identify predictors of T2 emotional outcomes.

Significant reductions were observed in depressive, state anxiety, and PTSD symptoms between T1 and T2, while trait anxiety remained stable. Poor family functioning and insecure attachment styles, particularly anxious attachment, were robust predictors of elevated emotional symptoms at follow-up. Avoidant attachment was uniquely associated with PTSD symptoms but not with depression or anxiety. Pharmacological treatment was related to lower symptom severity across all domains.

The findings underscore the influence of relational and familial factors in shaping psychological responses to disaster-related trauma in children with ADHD. Post-disaster interventions should incorporate attachment-informed and family-centered approaches alongside pharmacological treatment to optimize recovery in this high-risk group.

At least a third of U.S. adults with ADHD do not access recommended treatments (medication or cognitive behavioral therapy [CBT]), and those receiving treatment face barriers (e.g., inconsistent availability of medication). We investigated systemic inequities in CBT access for adults with ADHD versus psychiatric diagnoses with similar prevalence.

We accessed and extracted publicly available listings from the Psychology Interjurisdictional Compact (PSYPACT) provider directory (N = 12,898) in April 2025.

Only 26.4% of PSYPACT providers explicitly offer any services for adult ADHD. They were nearly three times more likely to treat adult depression (69.2%) and anxiety (74.0%). CBT for adult ADHD was offered by just 21.3% of providers.

U.S. psychologists are chief CBT providers for adult mental disorders; however, they systemically underserve adults with ADHD. Contributors to this inequity must be identified to advance adult ADHD care, as untreated ADHD is a costly public health burden.

Although inattention characterizes both pediatric attention deficit hyperactivity disorder (ADHD) and anxiety disorders, it is unclear whether the underlying neurocognitive mechanisms are shared or distinct. We compared behavioral performance and event-related potentials (ERPs) indexing discrete stages of attention across children with ADHD-only, Anxiety-only, co-occurring ADHD+Anxiety, and typically developing (TD) peers.

One hundred eleven children (7–11 years) completed three computerized attention tasks while high-density electroencephalography (EEG) was recorded. Behavioral indices (accuracy, reaction time, post-error slowing) and ERP/EEG markers of attentional engagement (aperiodic exponent), stimulus discrimination (N2), action selection (P3), performance monitoring (error-related negativity; ERN) and evaluation (error positivity; Pe) were analyzed.

Relative to TD children, all clinical groups showed reduced modulation of the pre-stimulus aperiodic exponent by cognitive load and attenuated N2 amplitudes across tasks, indicating shared alterations in dynamic arousal and stimulus discrimination. Distinct patterns between the ADHD and Anxiety groups were identified at the attentional engagement, performance monitoring, and performance evaluation phases. The Anxiety-only group displayed steeper pre-stimulus aperiodic exponents preceding correct versus incorrect trials, larger ERN amplitudes relative to the ADHD+Anxiety group, and reduced Pe amplitudes relative to the TD group and ADHD+Anxiety groups, suggesting heightened error detection, but reduced conscious appraisal. In contrast, the ADHD-only group showed reduced post-error slowing, indicating weaker self-monitoring and adaptive control.

Inattention in ADHD and anxiety is driven by both shared and distinct neurophysiological mechanisms. Shared alterations in early attentional engagement and stimulus processing coexist with disorder-specific differences in error monitoring and behavioral adjustment. These results position multimodal neurophysiological biomarkers as valuable tools for differential diagnosis and for guiding targeted interventions.

The American Academy of Pediatrics (AAP) recommends behavioral therapy as first-line evidence-based treatment for young children with ADHD, and in combination with medications for children ages 6 years and older. However, a significant percentage of young children are receiving medication treatment for ADHD rather than behavioral treatment. There is limited research capturing parent experiences of barriers to implementing behavioral health services for young children with ADHD diagnoses. This paper seeks to fill this gap by exploring these perceived barriers among parents of children diagnosed with ADHD.

Parents of children with ADHD diagnoses (N = 29) were invited to participate in four focus groups to discuss their experiences with accessing treatment for their child. Focus group participants were recruited from one Southeast city through an ADHD parental support group and nationally from parents attending a conference on ADHD.

Three themes emerged as perceived barriers that impact ADHD treatment. Parents reported barriers that can be conceptualized as (1) misconceptions and stigma; (2) availability of financial and time-related resources; and (3) treatment messaging and provider coordination. These barriers may be more pronounced for parents of young children with ADHD living in the Southeast.

Parent responses about perceived barriers in this study suggest a need for better coordinated care of ADHD across places of service, providers, and families. These findings may inform future efforts to improve access to and utilization of evidence-based treatments for ADHD in the Southeast and nationwide.

Previous research has revealed that individuals with ADHD exhibit difficulties in social functioning including obtaining and maintaining quality friendships. Cognitive disengagement syndrome (CDS) symptoms and internalizing symptoms frequently co-occur with ADHD symptoms and negatively influence social functioning, yet relatively little is known about how these symptoms uniquely relate to friendship features.

The present study sought to examine associations among these variables in a large, multi-site sample of emerging adults. Participants (N = 4,756; 18–29 years; 72.7% female; 79.8% White) enrolled in five universities in the United States completed measures of ADHD, CDS, internalizing symptoms, and friendship features.

Moderated conditional effects modeling revealed that internalizing symptoms accounted for significant variance in the association between ADHD symptoms and friendship features in all models. CDS symptoms were a significant moderator of the association between ADHD symptoms and friendship features (both positive and negative) such that there was a weaker association between ADHD symptoms and friendship impairment at higher levels of CDS symptoms.

Our findings suggest that CDS symptoms may buffer the association between ADHD and friendship features. Future research should continue to explore the associations among ADHD, CDS, and internalizing symptoms and their impact on friendship functioning.

ADHD is a highly prevalent neurodevelopmental disorder that is associated with elevated rates of co-occurring psychiatric symptoms. The present study evaluated the role of functional impairment in mediating the association between ADHD symptoms and psychiatric symptoms, as well as the moderating role of temperament traits.

Participants included two cohorts: an early childhood longitudinal sample (ages 2–4 years; n = 93) and a middle childhood cross-sectional sample (ages 7–11 years; n = 92). Both cohorts were oversampled for ADHD diagnosis or concerns. ADHD symptom severity, psychiatric symptoms, functional impairment, and temperament were assessed by caregiver report. Linear mediation and moderated mediation models were conducted, with ADHD symptom severity as the independent variable, functional impairment as the mediator, and psychiatric symptoms as the dependent variable; additionally, baseline psychiatric symptoms were covaried in the longitudinal early childhood analysis.

Across both samples, we found significant mediation effects for depression and aggression. In the middle childhood sample, functional impairment also fully mediated the association between ADHD and anxiety symptom severity. In the moderated mediation models, negative affect enhanced indirect effects on depression in early childhood and aggression in middle childhood. There were no protective effects of surgency.

Intervention specifically targeting functional impairment in this population has key clinical implications as it may help reduce the elevated risk of psychiatric comorbidity in the ADHD population, particularly in children with elevated levels of negative emotionality who are seemingly at highest risk.

Evidence-based assessments for ADHD include the collection of standardized ratings of Diagnostic and Statistical Manual of Mental Disorders symptoms. There is limited research on ADHD diagnostic procedures in Hispanic/Latino children and a growing concern that ADHD may be underdiagnosed due to language barriers that exist between parents and the standardized measures. To address this gap, we examined potential language related biases in the assessment of ADHD among Spanish-speaking parents.

The sample was 107 Hispanic/Latino, Spanish-speaking parents of children in kindergarten or first grade. The Spanish translated versions of the Disruptive Behavior Disorders Rating Scale (DBD-RS), Strength and Difficulties Questionnaire (SDQ), and Impairment Rating Scale (IRS) were administered to assess ADHD symptoms, concurrent validity, and the influence of time since arrival in the United States on parent ratings.

The Spanish DBD-RS demonstrated strong internal consistency for both Inattention (α = .85) and Hyperactivity/Impulsivity (α = .85) subscales. Parent ADHD ratings were positively correlated with SDQ Hyperactivity/Inattention scores (r = .38, p < .001), supporting concurrent validity. In regression analyses, parent time in the U.S. significantly predicted IRS impairment scores beyond ADHD symptoms (ΔR² = .036, p = .035).

Despite limitations such as reliance on self-report measures and cultural heterogeneity in the sample, this research contributes to understanding ADHD assessment in an under-studied ethnic group. Our findings contribute to ongoing efforts to refine diagnostic tools and promote equitable access to ADHD evaluations that are culturally appropriate for Hispanic/Latino children.

This study aimed to provide a representative indication of the accessibility of both adult and child ADHD assessments in Australia for psychologists, psychiatrists, and paediatricians. Accessibility was considered in terms of clinician availability, wait times for an initial session, initial session costs, and total assessment costs across Australian states and territories, remoteness areas, and socioeconomic ranges.

Using a secret shopper design, researchers posed as potential consumers seeking an ADHD assessment for themselves and/or their child. A total of 736 clinicians were contacted via telephone between May and August 2024.

Fifty-nine percent of clinicians responded, and 49.8% of respondents were available to book an ADHD assessment. The average wait times for psychologists, psychiatrists, and paediatricians were 7, 16, and 31 weeks, respectively (Mdn = 3, 15, and 26; IQR = 7, 16, and 31). The average initial session costs and estimated total assessment costs were $266 and $1,622 for psychologists (Mdn = 250 and 1,625; IQR = 57 and 929), $748 and $1,163 for psychiatrists (Mdn = 750 and 1,086; IQR = 340 and 555), and $500 and $598 for paediatricians (Mdn = 495 and 585; IQR = 123 and 739).

This study identified substantial barriers to ADHD assessment accessibility in Australia. Low clinician availability, long wait times, and high costs for assessments are all factors contributing to healthcare access inequality. Policy changes and investment, as well as further research into contributing factors, are needed to improve availability and accessibility.

Attention-Deficit/Hyperactivity Disorder (ADHD) has gained increasing visibility in public discourse on mental health, particularly in adulthood, while remaining associated with stigma, oversimplification, and misinformation. The present study aimed to identify mental representations of ADHD among Brazilian adults with and without a diagnosis.

This qualitative, exploratory, cross-sectional study included a non-probabilistic sample of 805 adults, comprising 463 participants with ADHD and 342 without a diagnosis. Data were collected online using the Free Word Association Technique, based on the inductive stimulus “ADHD.” Analyses were conducted using IRaMuTeQ software, including word cloud analysis, Descending Hierarchical Classification, and specificity analyses, complemented by thematic content analysis.

Results were primarily organized into four classes: (a) Stigma and delegitimization of ADHD, characterized by pejorative labels and simplified understandings of the condition; (b) Distress and Insecurity, reflected in feelings of insecurity, frustration, and low self-esteem; (c) Technical-Diagnostic Perspective on ADHD, centered on symptoms such as inattention, deficits, and hyperactivity; and (d) Dysfunctional behaviors, related to difficulties with organization, procrastination, and overload. Overall, more similarities than differences were observed in how participants with and without ADHD represented the disorder.

These findings suggest that ADHD is socially constructed as an experience that extends beyond its clinical definition, shaped by symbolic, normative, and affective processes. Accordingly, there is a need for clinical and psychoeducational practices that integrate diagnostic knowledge with subjective experiences and the sociocultural conditions that influence distress and daily functioning in the Brazilian context.

Parental mental health plays a critical role in the wellbeing of the family, yet few studies have examined how parental ADHD affects postpartum depression and anxiety. This study investigates the hypothesis that parent (including coparent) ADHD symptoms are associated with postpartum depressive and anxiety symptoms.

117 mother-father dyads (half with parental ADHD) were recruited when their infants were 6 to 10 months old. Participants completed questionnaires on ADHD, depression, anxiety, and social support. Clinician-administered semi-structured interviews assessed ADHD symptoms and psychiatric histories.

Participants in ADHD and non-ADHD dyads were demographically comparable but differed in prevalence of prior mood disorder (47% vs. 24%). Individuals with ADHD had significantly higher odds of moderate-to-severe depressive (OR = 2.70, 95% CI [1.10, 6.62]) and anxiety symptoms (OR = 4.58, 95% CI [1.82, 11.53]). Parallel mixed effects models accounting for parent dyad found that self-reported and clinician-reported ADHD symptoms and prior mood disorder history were significant predictors of depressive and anxiety symptoms (p < .025). Coparent ADHD symptoms were significantly associated with postpartum mood symptoms in the self-report models only. Higher perceived social support was associated with fewer depressive symptoms, approaching or reaching statistical significance in self- and clinician-report models, respectively. Secondary analysis identified self-reported ADHD symptoms and prior mood disorder as predictors of postpartum depressive and anxiety symptoms regardless of parent sex (p < .05).

Findings suggest that parental ADHD – in either parent – contributes to postpartum psychological distress. Screening and treatment of ADHD in new parents may reduce depressive and anxiety symptoms for those showing ADHD symptoms and their coparents, supporting the mental health outcomes of the whole family.

To examine the effect of attention-deficit hyperactivity disorder (ADHD) on sex differences in the hazard risk of a physical disease (PD) in childhood and adolescence, per ICD-10 criteria.

The Danish population born from 1984 to 1995, comprising over 800,000 individuals, was studied for the 13 different ICD-10 PD categories with ADHD as a time-dependent exposure in time-to-event settings. Time from birth to first episode PD, emigration, death, or 31st December 2017, whichever occurred first, was analyzed by use of piecewise Cox models.

Individuals with an ADHD diagnosis had higher or similar hazard risk than undiagnosed individuals throughout follow-up. Across all PD categories, baring malignant neoplasms, ADHD-diagnosed individuals had a higher hazard risk from teen age. In the general population, females had higher hazard risk of most PDs from teen age or early adolescence, while males had higher hazard risk in early childhood. Dispersed modification occurred in the hazard difference between sex post-ADHD diagnosis. For eye and adnexa diseases in childhood, males had about a 15% added hazard that of females in the general population, while females had twice the hazard of males among those diagnosed with ADHD. In the general population of young adulthood, females faced a hazard risk of endocrine, nutritional, and metabolic diseases nine times higher than that of males, with an ADHD diagnosis reducing this ratio by half.

The time-dependent ADHD diagnosis alters sex differences in the vulnerability to certain PD categories at various ages, while ADHD considerably increases vulnerability to all PDs except malignant neoplasms.

Studies have provided evidence that mind wandering (MW) is involved in the symptomatology of attention deficit/hyperactivity disorder (ADHD). One of the notable categorizations of MW is based on the dimension of intentionality, in which intentional MW is labeled as deliberate MW (D-MW) while the unintentional form is called spontaneous MW (S-MW). S-MW has been reported to be associated with lapses of attention or impulsive behaviors in individuals with ADHD. Using self-report and behavioral measures, the present study aimed to replicate the finding that scores on the S-MW scale predict those on the ADHD Self-Report Scale (ASRS) and to examine whether task performance under the S-MW state similarly predicts the scores on the ASRS scores.

The participants completed the ASRS and the D-MW and S-MW scales several days before performing the laboratory task (i.e., the continuous counting Stroop task). During the Stroop task (576 trials × 2 blocks), experience sampling probes were presented (20/block), which requested the participants to report their attentional state (i.e., concentrated, D-MW, S-MW, or other).

A univariate analysis showed that the accuracy of the Stroop task was remarkably lower under S-MW than under D-MW. Multiple regression analyses showed that scores on the S-MW scale and the accuracy of the Stroop task in the S-MW state independently predicted the ASRS scores.

These results may indicate that individuals with ADHD could suffer from two different types of interference stemming from S-MW.

Since DSM-5, ADHD has been classified as a neurodevelopmental disorder, and this placement has often reinforced dominant models that emphasize neurobiological mechanisms—treating attention as an internal trait shaped by executive dysfunction or dopaminergic imbalance. While these frameworks offer valuable insights, they often marginalize the ecological, relational, and sociomaterial contexts in which attention arises or collapses. Context is too often treated as background rather than condition.

This paper proposes a field-based reconceptualization of attention: a relational ontology in which patterns of behavior and experience gathered under the ADHD diagnosis are not solely located within the individual but emerge from dynamic tension between organism and environment.

Drawing from ecological psychology, dynamic systems theory, and phenomenological psychiatry, we develop the notion of fielded attention—a model in which attention is not a fixed trait but a modulation shaped by rhythm, affordance, and environmental curvature. We conduct a conceptual analysis in three stages: (1) critique of trait-based diagnostic frameworks that statistically neutralize context; (2) elaboration of a field ontology of attention that reframes breakdowns as ruptures in relational coherence; and (3) derivation of translational implications for research and care design.

The analysis identifies an epistemic shift in which environmental and social structures are often flattened into reductionist risk factors, and heterogeneity in ADHD symptom expression is reframed as field sensitivity—a signal of developmental plasticity rather than diagnostic noise. Translational implications include the design of learning and care environments (including architectural and temporal structure) and adoption of field-sensitive research methods such as ecological momentary assessment and spatial diaries.

Rather than reject biological models, this framework resituates them within broader ecologies of modulation. By repositioning context as ontologically central, fielded attention advances a more ethically responsive and developmentally situated account of ADHD.

Theoretical accounts of ADHD predict impaired learning under partial reinforcement and altered behavioral persistence under extinction. One of these theories (Amsel, 1992) postulates increased negative emotional responding (i.e., frustration) underlies these impairments, but to date emotional responding during instrumental learning has received limited attention. The current experimental study investigated behavioral and emotional responding during an instrumental learning task under different reinforcement schedules.

Eighty-four children with ADHD and 83 neurotypical children completed a simple instrumental learning task under a continuous (100%), partial (33%) or stretching ratio (i.e., schedule thinning; 100%–33%) reinforcement schedule, followed by a four-minute extinction phase. Negative and positive emotional expressions of the children were assessed during task completion.

No group differences were found in either speed of acquisition or behavioral persistence under extinction with the reinforcement schedules applied in the current study. Across groups, partial reinforcement and stretching the ratios resulted in more behavioral persistence compared to continuous reinforcement, supporting the presence of a PREE effect. Children with ADHD showed more negative emotional expressions during both acquisition and extinction, irrespective of reinforcement condition. No diagnostic group or condition differences were found in the number of positive emotional expressions.

Findings may have implications for instrumental learning based psychosocial treatments for children with ADHD, as their efficacy can be impacted by increased emotional responding.

The objective of this analysis was to describe the effects of methylphenidate-mediated symptom improvement on functional impairments in adults with ADHD.

This is an exploratory study of self-reported functional impairment on the Weiss Functional Impairment Rating Scale (WFIRS-S) in 351 ADHD adults treated in a forced dose, double blind (DB), randomized, parallel clinical trial of a 16-hr methylphenidate stimulant (PRC-063) for 4 weeks followed by open-label (OL; N = 147) for 6 months.

During the 4-week DB period, there was a statistically significant response to medication versus placebo in the WFIRS-S domain of “work.” Forty percent of DB subjects, assigned a random dose of medication, showed functional improvement as defined by the Minimal Clinical Important Differences (MCID) of the WFIRS. At the end of DB, one third of subjects had scores below symptomatic and functional impairment thresholds and two thirds by the end of OL. Although the OL period was uncontrolled, when all subjects had been dose optimized with sufficient time for functional impairment to manifest, all WFIRS functional domains showed clinically-relevant improvements from baseline to end of the 6-month OL (p < .0001). There was a fair-to-moderate correlation between change in symptoms and change in function, but ADHD symptoms were about twice as sensitive to change. The strongest predictor of improvement in function was greater improvement in ADHD symptoms. Younger age predicted greater functional impairment.

This study of the relationship between change in symptoms and functional outcome illustrates that improvement in symptoms may be associated with an almost cotemporaneous improvement in function, that increases over time. Identification of subjects who are symptom responders with residual functional impairment suggests the need for additional intervention to target residual functional difficulty. Further research needs to replicate this methodology using an individually dose optimized design to demonstrate full potential for change and to confirm the domains of functioning in adults with ADHD that are most responsive to stimulant treatment.

https://clinicaltrials.gov/study/NCT02139124.

Grit is a potential resilience factor that might help expand ADHD’s conceptualization and inform empowering interventions. Yet, no work has examined how components of grit, particularly consistency of interests (COI), may relate to ADHD symptom severity and impairment. Additionally, it is unclear whether these relations may differ with respect to one’s race and ethnicity. Thus, the current study aimed to examine whether race and ethnicity moderate grit and COI’s relations with ADHD symptom severity and impairment in college students.

Participants, aged 18 to 25 years, were derived from two samples of a multisite college ADHD study: Exploratory Sample (N = 1,771; M_age = 19.21, SD = 1.40) and Confirmatory Sample (N = 3,809; M_age = 19.11, SD = 1.31). All participants self-reported ADHD symptom severity, functional impairment, and levels of grit.

Examination of main effects across samples revealed that grit and COI were significantly and negatively associated with ADHD symptom severity. Further, in a sample of participants with five or more ADHD symptoms (N = 1,153; M_age = 19.22, SD = 1.41), follow-up analyses investigating impairment revealed that grit had a significant, positive relation with impairment, and COI had a significant, negative relation with impairment. Grit’s relations with ADHD symptom severity and impairment were generally consistent across race and ethnicity. Yet, there was a significant moderating effect with respect to the White versus Asian comparison concerning COI-ADHD relations. Follow-up analyses revealed that the strength of these relations was significantly weaker in Asian college students.

Results provided greater specificity in grit’s role as a resilience factor for ADHD and highlighted the need for further exploration of resilience factors to inform more comprehensive conceptualizations of ADHD in Asian college students.

Research suggests there is a higher prevalence of anxiety in individuals with ADHD compared to those without ADHD. However, estimated prevalence rates vary greatly due to differences in methodologies used across studies. This study is the first meta-analysis investigating differences in anxiety measure scores between adults with and without ADHD, and possible moderators of this effect.

Our analysis included 58 studies that compared anxiety scores in adults with/without ADHD (N = 18,821; k = 112).

The average effect size (Hedges’s g) of anxiety scores in those with ADHD relative to controls was 0.77 (SE = 0.066); a medium effect. The only significant moderator was the type of comparison group used, with comparisons to non-clinical control groups (g = 0.954, SE = 0.08) yielding significantly larger effects than comparisons to clinical control groups (g = 0.437, SE = 0.09). None of the other moderator variables examined (Method of characterising ADHD, Anxiety Measure Type, Anxiety Measure Focus, Age or Gender) moderated the effect. There was some evidence of publication bias, therefore results should be interpreted with this in mind.

Overall, this study indicates that ADHD is associated with higher levels of anxiety symptomology. This has important implications in the diagnosis and treatment of individuals presenting with ADHD or anxiety, including the consideration and screening of each of these conditions as potentially co-occurring with the other. Adaptions made to clinical practice in line with this would better support this population, improve symptom management and overall quality of life. Suggestions for future research are discussed.

Attention deficit hyperactivity disorder (ADHD) has been associated with comorbid conditions, especially psychiatric comorbidities. On the other hand, getting an ADHD diagnosis has been linked to children’s relative age. The aim of this study was to describe diagnostic patterns of ADHD patients of all ages, and to compare comorbidity and birth month between ADHD patients and matched controls.

This nationwide study cohort included incident ADHD patients with records of ADHD medication and/or ADHD diagnosis in Finland during 2015 to 2020, and with no such records during 2010 to 2014. Four controls were matched with each patient based on age, gender, and place of residence.

Altogether 66,146 incident ADHD patients and 256,270 matched controls were identified, and their average follow-up time was 3.5 years. Mean age at the first ADHD diagnosis was 15.9 years for males and 22.3 for females. Prior to being diagnosed with ADHD, patients visited health care remarkably more often than controls. Comorbid diagnoses were the most prevalent at index date, and compared to controls, the prevalence of these comorbidities within 3 years preceding the index date increased more in ADHD patients. The odds of ADHD increased with later birth months across all age-gender groups, except among girls under 6 years of age. The association was more pronounced among males.

ADHD is associated with a significant comorbidity burden across all age groups, even before ADHD diagnosis. Individuals who are younger in relative age are more likely to be diagnosed with ADHD.