Diagnosis and Prescribing Patterns of Adult Attention-Deficit ‎Hyperactivity Disorder in a Tertiary Care Hospital in the United ‎Arab Emirates: A Retrospective Study

Introduction

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by persistent patterns of inattention, hyperactivity, and impulsivity across the lifespan.^1–7 Although ADHD is most commonly identified during childhood, symptoms frequently persist into adulthood, where they continue to exert clinically meaningful effects on functioning and quality of life.^7–11 Despite this persistence, adult ADHD remains substantially underrecognized, with delayed, missed, or inaccurate diagnoses frequently reported in adult populations, particularly outside specialized psychiatric services.^12–16 Estimates suggest that fewer than one in five adults with ADHD receive an accurate diagnosis and appropriate treatment, highlighting persistent gaps in recognition and management within routine healthcare systems.^17–19

The underdiagnosis of adult ADHD reflects a complex interplay of patient-level, provider-level, and system-level barriers. Stigma surrounding mental health conditions, cultural perceptions of neurodevelopmental disorders, and socioeconomic disadvantage may hinder help-seeking and continuity of care, contributing to disparities in access and treatment adherence.^1,20,21 Within healthcare systems, limited awareness of adult ADHD, diagnostic uncertainty, provider biases, financial constraints, including restricted insurance coverage, and insufficient access to specialized services further delay assessment and intervention, adversely affecting patient outcomes.^17,22,23 These barriers are particularly relevant in general outpatient settings, where adult ADHD often presents alongside other psychiatric or medical conditions rather than as a primary diagnostic concern.

In adulthood, ADHD is associated with persistent functional impairments that extend beyond childhood academic difficulties to affect occupational performance, interpersonal relationships, and daily organization.^1,24,25 Adults with ADHD commonly experience sustained difficulties with attention regulation, task initiation, and executive functioning throughout the day, resulting in cumulative functional burden.²⁶ These impairments are linked to reduced quality of life and significant health and economic consequences, including increased healthcare utilization, reduced productivity, and broader societal costs.^6,27–31 Psychiatric comorbidities, particularly anxiety and depressive disorders, are highly prevalent among adults with ADHD and frequently complicate diagnostic assessment through symptom overlap and diagnostic overshadowing, contributing to diagnostic complexity and variability in clinical management.^32–34 Improving recognition and management of adult ADHD has important clinical implications, including optimizing treatment outcomes, reducing functional impairment, and minimizing the burden of untreated comorbid conditions.

Globally, awareness of ADHD in adults has increased in recent years, supported by expanding research and evolving diagnostic frameworks.^35,36 However, empirical evidence describing adult ADHD diagnosis, comorbidity patterns, and prescribing practices remains limited in the Middle East and Gulf region, including the United Arab Emirates (UAE), where available studies are few and heterogeneous.^37–43 In particular, robust real-world clinical data are scarce on how adult ADHD is identified across outpatient specialties, the extent to which it is documented as a primary versus secondary diagnosis, and how pharmacological treatment is prescribed in the presence of psychiatric comorbidity.

To address these gaps, the present study conducts a retrospective analysis of adult ADHD cases managed within a tertiary care hospital in the UAE, aiming to characterize diagnostic patterns across outpatient specialties, the burden and distribution of psychiatric comorbidities, and pharmacological prescribing practices in routine adult ADHD care.

Materials and Methods

Study Design

This study was conducted and reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines for observational research.⁴⁴ A retrospective observational study design was employed, utilizing routinely collected clinical data extracted from the electronic health record (EHR) system.

Setting

The study was conducted at Mediclinic Parkview Hospital (MPAR), Dubai, United Arab Emirates. MPAR is a Joint Commission International (JCI)–accredited tertiary healthcare facility providing multidisciplinary outpatient and inpatient services across more than 46 medical specialties. Data extraction was performed using a structured abstraction framework to ensure consistency across records, enabling assessment of diagnostic practices across multiple outpatient specialties.⁴⁵

Study Population

The study population included all adult patients aged 18 years and above with a documented diagnosis of attention-deficit/hyperactivity disorder (ADHD), identified using clinician-documented ICD-10 (International Classification of Diseases, Tenth Revision) diagnostic code F90.x, recorded in the electronic health record (EHR) between May 2023 and August 2024 (post–COVID-19 period). The date of diagnosis was defined as the first recorded diagnostic encounter at the study site. Prior ADHD diagnoses made outside the study institution (during childhood or in other healthcare settings) could not be systematically verified and were not distinguished from newly identified cases. All eligible cases meeting the diagnostic criterion during the study period were included, and no sampling was performed. The study size was therefore determined by the total number of eligible adult ADHD cases identified at the study site during the predefined study period.

Efforts to minimize selection and information bias included incorporating all eligible cases ‎within the specified timeframe, using standardized ICD-10 diagnostic codes, and structured ‎extraction of data from electronic health records.‎

Demographic and clinical variables extracted included age, gender, date of diagnosis (defined as the first recorded encounter with ICD-10 code F90.x at the study site), ‎diagnosing outpatient specialty, ADHD diagnostic hierarchy (primary versus secondary ‎diagnosis), ADHD subtype, psychiatric and neurological comorbidities, and prescription data. ‎Prescription data captured both ADHD-specific pharmacotherapy and medications prescribed ‎for associated psychiatric or medical comorbidities. Follow-up visits were recorded ‎descriptively, and patient-level data were longitudinally structured using unique patient identifiers to link multiple visits per patient across the study period.

Age was treated as a quantitative variable and categorized into standardized five-year intervals to facilitate descriptive analysis and comparability with prior epidemiological studies.^46,47

Data Collection and Variables

All variables were specified before data analysis to minimize analytical bias. Diagnostic classifications were based on clinician-documented diagnoses recorded in the electronic health record (EHR) at each clinical encounter. ADHD diagnostic yield by specialty was operationalized as the proportion of adult ADHD diagnoses relative to the total number of unique patients seen within each specialty during the study period. This patient-based definition enabled a more interpretable comparison of diagnostic activity across outpatient services.

Statistical Analysis

Statistical analyses were performed using IBM SPSS Statistics for Windows, Version 30.0 ‎‎(IBM Corp., Armonk, NY, USA). Descriptive statistics, including frequencies and proportions, ‎were used to summarize demographic characteristics, diagnostic patterns, comorbidity profiles ‎and prescribing practices.‎

One-way analysis of variance (ANOVA) was used to compare the diagnostic yield for ADHD ‎across outpatient specialties, using rate-based measures. Assumptions for parametric testing ‎were assessed prior to analysis. Chi-square tests were used to examine associations among ‎categorical variables, including demographic characteristics, diagnosis type, distribution of ‎ADHD subtypes, presence of comorbidities, and medication prescribing patterns.‎

Records with missing data were excluded from specific analyses on a variable-by-variable ‎basis, and no imputation procedures were applied. All analyses were exploratory and ‎associative in nature; no sensitivity analyses were conducted, and no causal inferences were ‎made. Statistical significance was defined as a two-sided P-value < 0.05.‎

Ethics Statement

The study was conducted in accordance with the Declaration of Helsinki. Given the ‎retrospective nature of the study and the use of anonymized, routinely collected clinical data, ‎the ethics committees approving the study waived the requirement for informed consent. All ‎data were anonymized at the point of extraction and stored securely on password-protected, ‎restricted-access systems accessible only to authorized research personnel. ‎

Ethical approval was obtained from the Mediclinic Middle East Research and Ethics ‎Committee (MCME REC approval No. MCME.CR.371.MPAR.2024), issued on 23 October ‎‎2024. Additional regulatory approval was granted by the Dubai Health Authority through the ‎Dubai Scientific and Research Ethics Committee (DSREC) (approval No. DSREC-02/2025_05), ‎obtained on 12 February 2025.‎

Results

Study Population and Demographic Characteristics

During the study period (May 2023–August 2024), a total of 157 adult patients aged ≥18 years ‎were diagnosed with attention-deficit/hyperactivity disorder (ADHD) across four outpatient ‎specialties at Mediclinic Parkview Hospital (Table 1).‎

Table 1 Demographic and Clinical Characteristics of Adult ADHD Patients Diagnosed at MPAR ‎‎(May 2023 – August 2024)‎

The cohort comprised 82 males (52.2%) and 75 females (47.8%). The most represented age groups were 18–19 years (24.8%) and 35–39 years (20.4%), followed by 40–44 years (16.6%) and 30–34 years (10.8%) (Figure 1).

Figure 1 Age Groups Distribution of Adult ADHD Patients Diagnosed at MPAR (May 2023 – August 2024).

Diagnosing Specialty and Diagnostic Hierarchy

Most ADHD diagnoses were made within Psychiatry (n=95, 61%), followed by Family ‎Medicine (n=44, 28%), Neurology (n=16, 10%), and Internal Medicine (n=2, 1%) (Figure 2).

Figure 2 Distribution of Adult ADHD Diagnoses by Outpatient Specialty at MPAR.

Overall, 61 patients (38.9%) had ADHD documented as a primary diagnosis, whereas 96 ‎patients (61.1%) had ADHD recorded as a secondary diagnosis alongside other psychiatric or ‎neurological conditions‎.

Temporal Patterns of Adult ADHD Diagnoses

The distribution of adult ADHD diagnoses was closely comparable across calendar years, with ‎‎80 cases (51%) identified in 2023 and 77 cases (49%) in 2024. Monthly case counts varied ‎within each year, with higher counts in May and June of both years and lower counts in ‎December 2023 and August 2024 in Dubai. Overall, monthly diagnosis counts showed temporal ‎variability without evidence of sustained increases or decreases. Monthly data are presented as ‎absolute counts (Figure 3).‎

Figure 3 Monthly Counts of Adult ADHD Diagnoses at MPAR (May 2023 – August 2024).

ADHD Subtypes and Psychiatric Comorbidities

The distribution of ADHD subtypes and associated psychiatric comorbidities among the 157 ‎adult patients is summarized in Table 2. Overall, 40 patients (25.5%) were diagnosed with ‎primary ADHD without comorbid conditions, with the predominantly inattentive subtype being ‎the most frequently documented. An additional 21 patients (13.4%) had a primary ADHD ‎diagnosis with comorbid generalized anxiety disorder (GAD), most commonly in combination ‎with the combined or inattentive subtypes.‎

Table 2 Distribution of ADHD Diagnoses and Comorbid Conditions Among Adult Patients

The majority of cases (n = 96, 61.1%) were classified as secondary ADHD with primary ‎comorbid psychiatric conditions. Within this group, generalized anxiety disorder (GAD) and ‎major depressive disorder (MDD) were the most frequently recorded co-occurring diagnoses.‎

Across the cohort, inattentive and unspecified ADHD subtypes were more commonly observed ‎than the hyperactive subtype, particularly among patients with comorbid psychiatric ‎conditions. This pattern of ADHD subtypes and comorbidity categories features the clinical heterogeneity and diagnostic complexity of adult ADHD presentations.‎

ADHD Medication Prescribing Patterns

Across the cohort, a total of 509 medications were prescribed, reflecting both ADHD-specific ‎treatments and medications for comorbid conditions. Methylphenidate-based formulations ‎accounted for 234 prescriptions (46.0%), including Concerta (31.2%) and Ritalin (14.7%). ‎Non-stimulant FDA-approved ADHD medication, specifically atomoxetine (1.8%), was ‎prescribed infrequently, while off-label psychotropic medications, such as bupropion (4.1%), ‎were used primarily for the management of associated psychiatric comorbidities rather than as ‎first-line ADHD treatments. (Table 3).‎

Table 3 Medication Prescribing Patterns Among Adults with ADHD

Statistical Analyses

One-way analysis of variance demonstrated a statistically significant difference in ADHD ‎diagnostic yield across outpatient specialties (F = 32.96, P < 0.001), indicating variation in ‎diagnostic rates between Psychiatry, Family Medicine, Neurology, and Internal Medicine. ‎

Chi-square analyses showed no statistically significant associations between ADHD diagnosis ‎type and gender (χ² = 0.89, P = 0.640), age group (χ² = 6.72, P = 0.945), or diagnosis year (χ² = ‎‎0.03, P = 0.984). Similarly, the presence of comorbidity did not differ significantly by gender ‎‎(χ² = 0.05, P = 0.824) or age group (χ² = 2.62, P = 0.918).‎

In contrast, significant differences were observed in the distribution of ADHD subtypes (χ² = ‎‎85.82, P < 0.001) and comorbidity categories (χ² = 77.84, P < 0.001), with inattentive and ‎unspecified subtypes occurring more frequently than the hyperactive subtype, and anxiety-‎related disorders being the most commonly documented comorbidities. Comorbidity presence ‎was significantly associated with diagnosis type, with psychiatric comorbidities more ‎frequently observed among patients with secondary ADHD diagnoses (χ² = 157.00, P < 0.001). ‎In addition, medication prescription categories differed significantly (χ² = 314.21, P < 0.001), ‎with methylphenidate-based formulations accounting for the largest proportion of ‎prescriptions. (Table 4) summarizes all inferential statistical analyses.‎

Table 4 Summary of Statistical Tests Examining Demographic, Diagnostic, and Comorbidity Patterns in MPAR Adult ADHD Data (May 2023–August 2024)

Discussion

This retrospective study, conducted at Mediclinic Parkview Hospital (MPAR), United Arab Emirates (UAE), provided an overview of‎ adult attention-deficit/hyperactivity disorder (ADHD) diagnostic and prescribing practices within a tertiary outpatient setting, interpreted within the context of existing regional and international literature. Importantly, the findings highlighted context-specific patterns across specialties within the UAE healthcare system, which remain underrepresented in the literature.

Adult ADHD diagnostic yield varied significantly across outpatient specialties, with Psychiatry ‎demonstrating the highest rate-based diagnostic yield, followed by Family Medicine, ‎Neurology and Internal Medicine. This pattern is consistent with global observations ‎identifying Psychiatry as the primary setting for adult ADHD diagnosis, while highlighting ‎under-recognition in non-psychiatric specialties, particularly in the presence of comorbid or ‎atypical presentations. This variation should be interpreted in the context of widely reported adult ADHD prevalence estimates ranging from 1.13% to over 30%, which reflect variability in recognition and diagnostic practices across different healthcare settings.‎^48,49 The specialty-specific diagnostic yields observed at MPAR fall toward the lower end of ‎expected detection in general healthcare contexts, reinforcing concerns about suboptimal ‎knowledge and underdiagnosis of adult ADHD outside specialized mental health services.^50,51 Contributing factors may include referral pathways, clinician awareness, insurance coverage ‎limitations and stigma surrounding adult ADHD in the region.‎³⁹

In addition, although overall case numbers were closely comparable across calendar years, monthly diagnosis counts varied over time, with recurrent peaks in late spring and lower counts observed during the summer months and toward the end of the calendar year, potentially reflecting reduced outpatient attendance in the UAE during school summer breaks and broader seasonal variation in healthcare utilization rather than a sustained directional pattern.

The cohort demonstrated a slight male predominance, consistent with existing literature ‎reporting higher diagnosis rates among males.⁵² Younger adults represented a substantial proportion of diagnosed cases.^11,37 Statistical analysis showed no significant associations between ADHD diagnosis type and gender or age group. In addition, no significant gender- or age-based differences in comorbidity prevalence were observed. These findings suggest that demographic characteristics alone did not drive diagnostic patterns within this cohort.

A substantial proportion of patients had ADHD documented as a secondary diagnosis in the presence of psychiatric comorbidities, most commonly anxiety and depressive disorders. This diagnostic hierarchy reflects challenges consistently reported in adult ADHD literature, where overlapping symptomatology and childhood-centric diagnostic frameworks may delay or obscure ADHD recognition. Similar patterns have been described across multiple international settings, including reports from adult ADHD clinics in neighboring Gulf countries, where psychiatric comorbidities were present in the majority of cases.⁵³

The observed association between diagnosis type and comorbidity presence reflects patterns in clinical classification rather than an independent relationship, highlighting the importance of comprehensive diagnostic evaluations in adult populations. The predominance of inattentive and unspecified ADHD subtypes, particularly among patients with psychiatric comorbidities, further illustrates the heterogeneity of adult ADHD presentations and supports prior evidence that non-hyperactive symptom profiles are more common in adults and may contribute to delayed recognition or misclassification.^54–57

Psychiatric comorbidities were highly prevalent in this cohort, with nearly three-quarters of patients presenting with at least one comorbid condition, most commonly generalized anxiety disorder and major depressive disorder.^11,58 This finding aligns with prior evidence demonstrating that psychiatric comorbidities are common and clinically significant among adults with ADHD and contribute to increased healthcare utilization and treatment complexity.^59,60 The marked imbalance in comorbidity categories highlights the heterogeneity of adult ADHD presentations and underscores the importance of comprehensive, technology-enabled assessment by suitably trained mental health professionals to identify co-occurring and alternative diagnoses accurately.⁶¹ In this study, the high prevalence of comorbidities directly supports the need for structured diagnostic assessment in routine clinical care.

Pharmacological treatment in this cohort was predominantly stimulant-based, with methylphenidate accounting for nearly half of all prescriptions. This prescribing pattern aligns with international clinical guidance supporting stimulants as first-line therapy for adult ADHD.¹ Non-simulant atomoxetine was prescribed less frequently, while off-label agents such as bupropion were more commonly observed among patients with co-occurring psychiatric conditions. The statistically significant difference observed in medication distribution reflects the central role of stimulant therapy while also reflecting the complexity of pharmacological management in multimorbid adult ADHD populations.^62–65

A total of 509 medications were prescribed to 157 patients, corresponding to an average of approximately 3.2 medications per patient, indicating frequent use of combination therapy, medication adjustments, and pharmacological management of comorbid conditions. These findings highlight the multifaceted nature of pharmacological management in adult ADHD, particularly in the presence of comorbid conditions, and support the need for individualized and flexible treatment strategies.^66–70

Medication availability should be considered when interpreting these findings. Previously documented supply disruptions at the study institution may have intermittently limited access to high-demand stimulant medications, including methylphenidate, potentially influencing prescribing continuity and treatment adherence during the study period.⁷¹

The diagnostic and prescribing patterns observed at MPAR mirror broader regional trends within the Middle East and North Africa, where adult ADHD diagnosis and management vary across healthcare systems. The concentration of diagnoses within psychiatric services and reliance on stimulant pharmacotherapy highlight the influence of local referral pathways, healthcare infrastructure, and cultural perceptions of ADHD.^72,73 These findings support the need for standardized, nationally relevant clinical pathways for adult ADHD within general outpatient services in the region.³⁸

The high prevalence of psychiatric comorbidities and the intensity of pharmacological treatment observed in this cohort suggest increased healthcare resource utilization. This finding is consistent with global evidence linking adult ADHD, particularly when accompanied by psychiatric comorbidity, to higher direct and indirect healthcare costs.²⁹ Investment in integrated care models and in evaluating the cost-effectiveness of adult ADHD interventions may help mitigate the long-term economic burden.⁷⁴

This study represents one of the few UAE-specific retrospective analyses of adult ADHD and benefits from real-world clinical data captured across multiple outpatient specialties within a tertiary care hospital. However, the retrospective design limited causal inference and relied on the completeness and accuracy of electronic health record documentation. The monthly variation analysis and the association between diagnosis type and comorbidity should be interpreted cautiously, given the limited observations and the inherent relationship between these variables, and are presented as descriptive findings. In addition, the diagnostic yield estimates may be influenced by differences in patient revisit frequency across specialties, which were not adjusted for in the analysis. The single-center setting may limit generalizability, and patient-reported outcomes, symptom severity measures, and objective assessments of treatment adherence were not available.

Future studies should employ multicenter designs across diverse healthcare settings in the UAE to improve generalizability and enable comparative analyses of adult ADHD diagnostic pathways and prescribing practices. Prospective longitudinal studies incorporating standardized diagnostic instruments, symptom severity measures, and patient-reported outcomes would allow evaluation of diagnostic stability, treatment effectiveness, and long-term adherence. Integration of healthcare utilization data, including appointment attendance and follow-up patterns, may clarify the influence of system-level and seasonal factors on diagnostic activity. Given the evolving role of artificial intelligence (AI) in clinical medicine and diagnosis, future research should also investigate how AI-assisted decision support systems, predictive models, and natural language processing tools could enhance the accuracy and efficiency of adult ADHD screening and diagnostic workflows.⁷⁵ In addition, studies assessing medication availability, supply chain disruptions, and their impact on prescribing continuity are warranted to contextualize treatment patterns in real-world settings better. Finally, economic evaluations examining the cost-effectiveness of integrated and multidisciplinary care models for adults with ADHD, particularly those with psychiatric comorbidities, would inform national policy development and clinical guideline refinement.

Conclusion

This retrospective analysis of adult ADHD in a single-center tertiary hospital in the United Arab Emirates demonstrated marked variation in diagnostic yield across outpatient specialties, with diagnoses occurring predominantly within psychiatric services and frequently in the presence of psychiatric comorbidity. ADHD was more often documented as a secondary diagnosis rather than as a standalone condition, underscoring the clinical complexity of adult presentations and the potential for under-recognition outside specialist mental health settings. Pharmacological management was largely stimulant-based, with methylphenidate formulations accounting for the largest proportion of prescriptions, alongside substantial pharmacological treatment of comorbid conditions. Collectively, these findings, within the limitations of the study design, highlight the need for refined, nationally relevant clinical pathways that support standardized assessment, cross-specialty collaboration, and integrated management of adult ADHD within the UAE healthcare system.