ADHD-hyperactive/impulsive subtype in adults

Emotional Dysregulation in Emerging Adult ADHD: A Key Consideration in Explaining and Classifying Impairment and Co-Occurring Internalizing Problems

OBJECTIVE

The current study sought to clarify and harness the incremental validity of emotional dysregulation and unawareness (EDU) in emerging adulthood, beyond ADHD symptoms and with respect to concurrent classification of impairment and co-occurring problems, using machine learning techniques.

METHOD

Participants were 1,539 college students (Mage = 19.5, 69% female) with self-reported ADHD diagnoses from a multisite study who completed questionnaires assessing ADHD symptoms, EDU, and co-occurring problems.

RESULTS

Random forest analyses suggested EDU dimensions significantly improved model performance (ps < .001) in classifying participants with impairment and internalizing problems versus those without, with the resulting ADHD + EDU classification model demonstrating acceptable to excellent performance (except in classification of Work Impairment) in a distinct sample. Variable importance analyses suggested inattention sum scores and the Limited Access to Emotional Regulation Strategies EDU dimension as the most important features for facilitating model classification.

CONCLUSION

Results provided support for EDU as a key deficit in those with ADHD that, when present, helps explain ADHD's co-occurrence with impairment and internalizing problems. Continued application of machine learning techniques may facilitate actuarial classification of ADHD-related outcomes while also incorporating multiple measures.

Functional impairment and quality of life in newly diagnosed adults attending a tertiary ADHD clinic in Ireland

BACKGROUND

Attention Deficit-Hyperactive Disorder (ADHD) is a neurodevelopmental disorder, often persisting into adulthood.

AIMS

To investigate the levels of functionality and quality of life (QoL) in adult patients newly diagnosed with ADHD and to compare with those without an ADHD diagnosis.

METHODS

Consecutive patients who were referred to and assessed in a tertiary adult ADHD clinic enrolled in the study. Diagnosis of ADHD was based on DSM-5 criteria. Functionality was measured using the Weiss Functional Impairment Rating Scale (WFIRS) and the Global Assessment of Functioning Scale (GAF). QoL was assessed with the Adult ADHD Quality of Life Questionnaire (AAQoL).

RESULTS

Three-hundred and forty participants were recruited, 177 (52.1%) females. Of them 293 (86.2%) were newly diagnosed with ADHD. Those with ADHD had significant lower functionality as it was measured with the WFIRS and GAF, and worse QoL (AAQoL) compared to those without. In addition, a significant correlation between GAF and WFIRS was found.

CONCLUSIONS

The results show that adults with ADHD have decreased functionality and worse QoL when compared against those presenting with a similar symptomatology, but no ADHD diagnosis. ADHD is not just a behavioural disorder in childhood, but a lifelong condition with accumulating problems that can lead to lower QoL and impaired functioning throughout adulthood.

Sex differences in physiological correlates of affectively driven decision-making behavior in adult ADHD

BACKGROUND

Sex differences in the symptomatology of adults with attention-deficit/hyperactivity disorder (ADHD) have often been overlooked when studying behavioral abnormalities. However, it is known that women exhibit considerably more stronger symptoms related to emotional competence than men. Since affective functions significantly influence the processing of risky decision-making and risk-engagement, we assume that risky behavior in ADHD is affected by sex differences. Therefore, we specifically investigated sex-specific effects on the interaction between emotionally induced changes in physiology and behavioral performance on a decision-making task.

METHODS

Skin conductance responses of twenty-nine adults with ADHD (n = 16 male; n = 13 female) and thirty-three adults in the control group (n = 14 male; n = 19 female) were recorded during the performance in a modified version of the Balloon Analogue Risk Task (BART). Additional questionnaires were used to reveal insights in the self-assessment of emotional competence, risk perception, and feedback sensitivity. Emotional arousal and decision-making behavior were analyzed using linear mixed-effects models.

RESULTS

Results showed different effects of sex on risk behaviors in controls and ADHD. In contrast to healthy controls, female adults with ADHD showed a significantly greater risk engagement in the BART compared to males with ADHD. This contrary sex relation was not observed in skin conductance responses and revealed a significantly different sex-dependent correlation of body response and behavioral task performance in ADHD. Comparisons with results from self-assessments furthermore indicate a reduced behavioral self-perception in women with ADHD, but not in men.

CONCLUSION

In summary, we found an altered interaction between physiological activity and risky behavior in women with ADHD. Thus, the present study indicates a reduced sensitivity towards the own bodily responses in women with ADHD, which could consequently cause increased risky DM behavior in daily life. The current results suggest that more consideration needs to be given to sex-specific effects on physiological processes and behavior in adults with ADHD.

Psychometric properties of the self-report version of the Strengths and Weaknesses of ADHD Symptoms and Normal Behavior Scale in a sample of Hungarian adolescents and young adults

The Strengths and Weaknesses of ADHD Symptoms and Normal Behaviour Scale (SWAN) measures the full spectrum of attention and activity symptoms, not just the negative end of the distribution. Previous studies revealed strong psychometric properties of the parent and teacher report versions; however, there is little research on the new self-report form of the SWAN. Therefore, our research aimed to explore the psychometric characteristics of the SWAN self-report. A non-clinical sample of young women (N = 664, mean age: 20.01 years, SD: 3.08 years) completed the SWAN self-report, the Strengths and Difficulties Questionnaire (SDQ) and the Mental Health Continuum Short Form (MHC-SF). We tested several models using confirmatory factor analyses to assess the factorial validity of the SWAN self-report. Distributional characteristics, convergent, and predictive validity were assessed. A bifactor model with a general factor and a specific inattention factor (bifactor-1) provided the best fit in our data (CFI = 0.977, TLI/NFI = 0.972, RMSEA = 0.053 [90% CI: 0.047 - 0.059], SRMR = 0.061, ω = 0.90). The reliability of the general ADHD factor was good (ωh = 0.87), and the specific inattention factor was acceptable (ωh = 0.73). The distribution of the SWAN self-report scores did not differ from the normal distribution. A strong correlation between the SWAN and the SDQ Hyperactivity subscale was found. The analyses revealed good predictive validity. Our results suggest that the SWAN self-report is a valuable tool for assessing symptoms of ADHD in adolescents and young adults.

Prevalence of adult attention deficit hyperactivity disorder in India: a systematic review and a cross-sectional study among young adults in Delhi-NCR

PURPOSE

The epidemiology of adult attention deficit hyperactivity disorder (ADHD) is not well explored in India. The present study aims to systematically review the literature on the prevalence of adult ADHD in India and also estimate the prevalence and sociodemographic correlates of adult ADHD among the young adults in Delhi-NCR.

METHODS

For the systematic review, 494 articles were identified of which 10 were included in the review. Simultaneously, a cross-sectional study was conducted involving 1665 adults (18-25 years; mean age 19.92) of both sexes (69.1% females) from different colleges in Delhi-NCR, India. Data was collected using structured interviews and standardized diagnostic tool ASRS V1.1 was used for screening of ADHD.

RESULT

The systematic review revealed a high prevalence of adult ADHD ranging from 5.48 to 25.7% among general and specific populations of India. Further, in the cross-sectional study, 14% of participants were screened positive for ADHD. While factors like South Indian origin and higher maternal education were associated with an increased risk of adult ADHD, low socioeconomic status was found to be protective.

CONCLUSION

Considering the high prevalence of adult ADHD in India, there is an urgent need to increase awareness regarding adult ADHD and identify vulnerable populations to facilitate informed interventions.

The Chinese Version of the Compensatory ADHD Behaviors Scale (CABS): A Study on Reliability, Validity, and Clinical Utility

Purpose

With the further development of attention-deficit/hyperactivity disorder (ADHD) research, more and more assessment tools related to ADHD have been used. However, there is still no measurement instrument to evaluate the compensatory behavior of ADHD in China. This study aimed to examine the reliability and validity of the Compensatory ADHD Behaviors Scale (CABS) adapted in Chinese and explore ecological characteristics in adults with ADHD using the CABS.

Patients and Methods

Data were collected from a sample of 306 adults (Mage = 26.43 years, SD = 5.32; 46.08% male). The original version CABS was translated into Chinese using the forward and backward translation procedures. Participants completed the CABS and questionnaires assessing ADHD symptoms and executive function. We utilized content validity, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and criterion validity to test the validity. Internal consistency and test-retest reliability were employed to test the reliability. Analysis of variance (ANOVA) was employed to compare ADHD subgroups based on gender, ADHD subtype, comorbidities, and medication status, while controlling for demographic variables as covariates.

Results

CABS exhibited good construct validity (two factors: present-oriented and future-oriented), content validity (content validity index: 0.98), internal consistency reliability (Cronbach's alpha coefficient: 0.85 to 0.87) and test-retest reliability (intraclass correlation coefficient: 0.59 to 0.88). The results of CFA showed acceptable fitness for each subscale. CABS demonstrated significant associations with inattention symptoms and plan/organizational abilities. Medicated ADHD individuals scored higher on future-oriented effectiveness subscale of CABS than non-medicated (F = 6.106, p = 0.014).

Conclusion

The results indicate that the Chinese CABS exhibited good validity and reliability. It can be considered a valid tool for assessing compensatory behaviors in Chinese adults with ADHD. Further research is needed to explore the connection between medication and compensatory behavior.

Data-driven profiles of attention-deficit/hyperactivity disorder using objective and ecological measures of attention, distractibility, and hyperactivity

In the past two decades, the traditional nosology of attention-deficit/hyperactivity disorder (ADHD) has been criticized for having insufficient discriminant validity. In line with current trends, in the present study, we combined a data-driven approach with the advantages of virtual reality aiming to identify novel behavioral profiles of ADHD based on ecological and performance-based measures of inattention, impulsivity, and hyperactivity. One hundred and ten Spanish-speaking participants (6-16 years) with ADHD (medication-naïve, n = 57) and typically developing participants (n = 53) completed AULA, a continuous performance test embedded in virtual reality. We performed hybrid hierarchical k-means clustering methods over the whole sample on the normalized t-scores of AULA main indices. A five-cluster structure was the most optimal solution. We did not replicate ADHD subtypes. Instead, we identified two clusters sharing clinical scores on attention indices, susceptibility to distraction, and head motor activity, but with opposing scores on mean reaction time and commission errors; two clusters with good performance; and one cluster with average scores but increased response variability and slow RT. DSM-5 subtypes cut across cluster profiles. Our results suggest that latency of response and response inhibition could serve to distinguish among ADHD subpopulations and guide neuropsychological interventions. Motor activity, in contrast, seems to be a common feature among ADHD subgroups. This study highlights the poor feasibility of categorical systems to parse ADHD heterogeneity and the added value of data-driven approaches and VR-based assessments to obtain an accurate characterization of cognitive functioning in individuals with and without ADHD.

Abnormal wiring of the structural connectome in adults with ADHD

Current knowledge of white matter changes in large-scale brain networks in adult attention-deficit/hyperactivity disorder (ADHD) is scarce. We collected diffusion-weighted magnetic resonance imaging data in 40 adults with ADHD and 36 neurotypical controls and used constrained spherical deconvolution-based tractography to reconstruct whole-brain structural connectivity networks. We used network-based statistic (NBS) and graph theoretical analysis to investigate differences in these networks between the ADHD and control groups, as well as associations between structural connectivity and ADHD symptoms assessed with the Adult ADHD Self-Report Scale or performance in the Conners Continuous Performance Test 2 (CPT-2). NBS revealed decreased connectivity in the ADHD group compared to the neurotypical controls in widespread unilateral networks, which included subcortical and corticocortical structures and encompassed dorsal and ventral attention networks and visual and somatomotor systems. Furthermore, hypoconnectivity in a predominantly left-frontal network was associated with higher amount of commission errors in CPT-2. Graph theoretical analysis did not reveal topological differences between the groups or associations between topological properties and ADHD symptoms or task performance. Our results suggest that abnormal structural wiring of the brain in adult ADHD is manifested as widespread intrahemispheric hypoconnectivity in networks previously associated with ADHD in functional neuroimaging studies.

Functional Near-Infrared Spectroscopy of English-Speaking Adults With Attention-Deficit/Hyperactivity Disorder During a Verbal Fluency Task

OBJECTIVE

Functional near-infrared spectroscopy (fNIRS) provides direct and quantitative assessment of cortical hemodynamic response. It has been used to identify neurophysiological alterations in medication-naïve adults with attention-deficit/hyperactivity disorder (ADHD). Hence, this study aimed to distinguish both medication-naïve and medicated adults with ADHD from healthy controls (HC).

METHOD

75 HCs, 75 medication-naïve, and 45 medicated patients took part in this study. fNIRS signals during a verbal fluency task (VFT) were acquired using a 52-channel system and relative oxy-hemoglobin changes in the prefrontal cortex were quantified.

RESULTS

Prefrontal cortex hemodynamic response was lower in patients than HCs (p ≤ ≤.001). Medication-naïve and medicated patients did not differ in hemodynamic response or symptom severity (p > .05). fNIRS measurements were not associated with any clinical variables (p > .05). 75.8% patients and 76% HCs were correctly classified using hemodynamic response.

CONCLUSION

fNIRS may be a potential diagnostic tool for adult ADHD. These findings need to be replicated in larger validation studies.

Subtype classification of attention deficit hyperactivity disorder with hierarchical binary hypothesis testing framework

Objective. The diagnosis of attention deficit hyperactivity disorder (ADHD) subtypes is important for the refined treatment of ADHD children. Although automated diagnosis methods based on machine learning are performed with structural and functional magnetic resonance imaging (sMRI and fMRI) data which have full observation of brains, they are not satisfactory with the accuracy of less than80%for the ADHD subtype diagnosis.Approach. To improve the accuracy and obtain the biomarker of ADHD subtypes, we proposed a hierarchical binary hypothesis testing (H-BHT) framework by using brain functional connectivity (FC) as input bio-signals. The framework includes a two-stage procedure with a decision tree strategy and thus becomes suitable for the subtype classification. Also, typical FC is extracted in both two stages of identifying ADHD subtypes. That means the important FC is found out for the subtype recognition.Main results. We apply the proposed H-BHT framework to resting state fMRI datasets from ADHD-200 consortium. The results are achieved with the average accuracy97.1%and an average kappa score 0.947. Discriminative FC between ADHD subtypes is found by comparing the P-values of typical FC.Significance. The proposed framework not only is an effective structure for ADHD subtype classification, but also provides useful reference for multiclass classification of mental disease subtypes.

Altered interaction of physiological activity and behavior affects risky decision-making in ADHD

Background

Adult attention-deficit/hyperactivity disorder (ADHD) is often associated with risky decision-making behavior. However, current research studies are often limited by the ability to adequately reflect daily behavior in a laboratory setting. Over the lifespan impairments in cognitive functions appear to improve, whereas affective functions become more severe. We assume that risk behavior in ADHD arises predominantly from deficits in affective processes. This study will therefore aim to investigate whether a dysfunction in affective pathways causes an abnormal risky decision-making (DM) behavior in adult ADHD.

Methods

Twenty-eight participants with ADHD and twenty-eight healthy controls completed a battery of questionnaires regarding clinical symptoms, self-assessment of behavior and emotional competence. Furthermore, skin conductance responses were measured during the performance in a modified version of the Balloon Analogue Risk Task. A linear mixed-effects model analysis was used to analyze emotional arousal prior to a decision and after feedback display.

Results

Results showed higher emotional arousal in ADHD participants before decision-making (β = -0.12, SE = 0.05, t = -2.63, p < 0.001) and after feedback display (β = -0.14, SE = 0.05, t = -2.66, p = 0.008). Although risky behavior was greater in HC than in ADHD, we found a significant interaction effect of group and anticipatory skin conductance responses regarding the response behavior (β = 107.17, SE = 41.91, t = 2.56, p = 0.011). Post hoc analyses revealed a positive correlation between anticipatory skin conductance responses and reaction time in HC, whereas this correlation was negative in ADHD. Self-assessment results were in line with the objective measurements.

Conclusion

We found altered changes in physiological activity during a risky decision-making task. The results confirm the assumption of an aberrant relationship between bodily response and risky behavior in adult ADHD. However, further research is needed with respect to age and gender when considering physiological activities.

Alarmingly high prevalence and lack of gender differences in ADHD among high school students: Screening for ADHD with ASRS among adolescents and working adults

Introduction: The aim was to examine the psychometric properties of the Polish version of the Adult ADHD Self-Report Scale (ASRS) among adolescents and adult working populations of different genders, the prevalence of ADHD, and its relationship to stress.

Materials and methods: A sample of 723 professionally active people and 1744 high school students participated in the study. Part A of the Adult ADHD Self-Report Scale (ASRS) was used to measure ADHD and the 4-item Perceived Stress Scale (PSS-4) was used to measure stress.

Results: Confirmatory factor analyses showed that the original 6-item two-factor solution of ASRS Part A had a satisfactory fit and showed basic measurement invariance between age groups and genders. Inattention and hyperactivity were related mostly similarly to stress in all groups. The prevalence of ADHD among adolescents was much higher than in previous reports, and no gender differences were found. About every fifth high school student and every tenth adult showed a risk of ADHD. The potential cause of the difference in the prevalence in the studied groups can be generation change.

Conclusions: ASRS is a well-functioning screening measure with good psychometric properties. It is a convenient option for large-scale epidemiological surveys necessary to understand potential generational changes in the prevalence of ADHD and the lack of gender differences among adolescents.

ADHD and Neurodegenerative Disease Risk: A Critical Examination of the Evidence

In this review, we undertake a critical appraisal of eight published studies providing first evidence that a history of attention-deficit/hyperactivity disorder (ADHD) may increase risk for the later-life development of a neurodegenerative disease, in particular Lewy body diseases (LBD), by up to five-fold. Most of these studies have used data linked to health records in large population registers and include impressive sample sizes and adequate follow-up periods. We identify a number of methodological limitations as well, including potential diagnostic inaccuracies arising from the use of electronic health records, biases in the measurement of ADHD status and symptoms, and concerns surrounding the representativeness of ADHD and LBD cohorts. Consequently, previously reported risk associations may have been underestimated due to the high likelihood of potentially missed ADHD cases in groups used as “controls”, or alternatively previous estimates may be inflated due to the inclusion of confounding comorbidities or non-ADHD cases within “exposed” groups that may have better accounted for dementia risk. Prospective longitudinal studies involving well-characterized cases and controls are recommended to provide some reassurance about the validity of neurodegenerative risk estimates in ADHD.

Improved attention linked to sustained phenylalanine reduction in adults with early-treated phenylketonuria

Pegvaliase is approved to reduce phenylalanine (Phe) levels for people with phenylketonuria (PKU). PRISM‐1 (NCT01819727) and PRISM‐2 (NCT01889862) data were analyzed to evaluate the relationship between Phe and inattention in adult participants with PKU. In the modified‐intent‐to‐treat population (N = 156), baseline mean (SE) plasma Phe was 1263 (29) μmol/L and the Attention Deficit Hyperactivity Disorder Rating Scale‐IV Inattentive (IA) symptoms score was 9.8 (0.5). Mean (SE) IA scores fell 9.0 (1.1) in Quartile 1 (Phe reduction between 1166 and 2229 μmol/L) versus 4.3 (0.7) in Quartile 4 (Phe reduction of 139 μmol/L to increase of 934 μmol/L), p = 0.004. Least squares mean (SE) change from baseline IA score was −7.9 (0.7) for participants with final Phe ≤ 360 μmol/L and −4.5 (0.7) for final Phe > 360 μmol/L, p < 0.001. In the inattention subgroup, IA scores fell 13.3 (1.5) in Quartile 1 (Phe reduction between 1288 and 2229 μmol/L) versus 6.2 (1.3) in Quartile 4 (Phe reduction of 247 to increase of 934 μmol/L), p = 0.009. Inattention symptoms improved among those whose Phe levels decreased, particularly those with high baseline IA scores. IA improvements were larger among participants with the greatest plasma Phe reductions, supporting this value as a therapeutic goal.

The Norwegian Translation of the Adult Attention-Deficit/Hyperactivity Disorder Quality of Life Scale: Validation and Assessment of QoL in 313 Adults With ADHD

OBJECTIVE

The aim of the study was to validate the Norwegian version of the Adult Attention-Deficit/Hyperactivity Disorder Quality of Life (AAQoL) scale and to explore Quality of Life (QoL) and functional outcomes in adults with ADHD.

METHOD

A total of 313 adults with ADHD participated in the study. Data were collected from medical records and self-report questionnaires. Confirmatory factor analysis was performed to assess the model fit of the translated AAQoL. Chi-square statistics and t tests were used to investigate sample characteristics.

RESULTS

The analyses showed acceptable model fit between data and the model. Chi square = 863.179 (371 df, p < .0000), root mean square error of approximation (RMSEA) = 0.069 (90% confidence interval [CI]), comparative fit index (CFI) = 0.873, and Tucker-Lewis index (TLI) = 0.821. Cronbach's alpha range for the scales was .761 to .869. The sample was characterized by poor QoL and impairment.

CONCLUSION

The translated AAQoL is showing good initial indications of validity with acceptable psychometric properties in the sample. ADHD was associated with impairments in QoL, symptoms, and functional outcomes.

Functional Impairment Mediates the Relationship Between Adult ADHD Inattentiveness and Occupational Outcome

OBJECTIVE

In spite of an expanding use of health-related quality of life assessment in research and treatment of ADHD, there is still limited knowledge about the role of impaired quality of life in symptomatic outcomes. This study investigates how specific functional domains affect the relationship between ADHD symptoms and occupational outcome.

METHOD

A total of 149 referred adults with ADHD participated in the study. We used mediation analyses to test a model with two 36-item short form health survey (SF-36) Mental Component scales, that is, role-emotion function and social function as mediators for the relationship between ADHD inattentiveness and occupational outcome.

RESULTS

The relationship between ADHD inattentiveness and occupational outcome was completely mediated by both role-emotion function and social function.

CONCLUSION

Role-emotion function and social function may identify specific aspects of functional impairment as potentially important treatment targets for ADHD patients with impaired occupational function. (J. of Att. Dis. 2016; 20(6) 510-518).

ADHD symptoms are differentially related to specific aspects of quality of life

OBJECTIVE

The objectives of this study were to investigate the relationships between ADHD symptoms and specific domains of the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) mental component.

METHOD

A sample of 149 adults participated in the study. Data were collected from the participant's medical records and from self-report questionnaires. Multiple regression analyses were applied to identify predictors of the SF-36 mental component outcomes.

RESULTS

The sample was highly impaired in terms of low health-related quality of life on all SF-36 mental component scales. The ADHD Self-Report Scale (ASRS) inattentiveness was the strongest predictor of vitality and the only significant predictor of role-emotional outcome. The ASRS hyperactivity/impulsivity was the strongest predictor of social function and the only predictor of mental health outcome.

CONCLUSION

Inattentiveness and hyperactivity/impulsivity were differentially related to specific quality-of-life domains. Inattentiveness was significantly predicting vitality and role-emotional outcomes, and hyperactivity/impulsivity predicted social function and mental health outcomes.

Pay attention to impulsivity: modelling low attentive and high impulsive subtypes of adult ADHD in the 5-choice continuous performance task (5C-CPT) in female rats

Varying levels of attention and impulsivity deficits are core features of the three subtypes of adult attention deficit-hyperactivity disorder (ADHD). To date, little is known about the neurobiological correlates of these subtypes. Development of a translational animal model is essential to improve our understanding and improve therapeutic strategies. The 5-choice continuous performance task (5C-CPT) in rats can be used to examine different forms of attention and impulsivity. Adult rats were trained to pre-set 5C-CPT criterion and subsequently separated into subgroups according to baseline levels of sustained attention, vigilance, premature responding and response disinhibition in the 5C-CPT. The behavioural subgroups were selected to represent the different subtypes of adult ADHD. Consequently, effects of the clinically used pharmacotherapies (methylphenidate and atomoxetine) were assessed in the different subgroups. Four subgroups were identified: low-attentive (LA), high-attentive (HA), high-impulsive (HI) and low-impulsive (LI). Methylphenidate and atomoxetine produced differential effects in the subgroups. Methylphenidate increased sustained attention and vigilance in LA animals, and reduced premature responding in HI animals. Atomoxetine also improved sustained attention and vigilance in LA animals, and reduced response disinhibition and premature responding in HI animals. This is the first study using adult rats to demonstrate the translational value of the 5C-CPT to select subgroups of rats, which may be used to model the subtypes observed in adult ADHD. Our findings suggest that this as an important paradigm to increase our understanding of the neurobiological underpinnings of adult ADHD-subtypes and their response to pharmacotherapy.

Adult ADHD: prevalence of diagnosis in a US population with employer health insurance

OBJECTIVE

The burden of attention-deficit/hyperactivity disorder (ADHD) in adults is increasingly recognized. This retrospective analysis was designed to estimate the prevalence of diagnosed ADHD in a population of insured, employed individuals and their dependents in the United States.

METHODS

Health care claims data obtained from the MarketScan Commercial Claims and Encounters Database were analyzed. Patients with ADHD were identified by at least two diagnostic claims per calendar year. Once identified, patient records were examined for evidence of continuing ADHD.

RESULTS

Between 2002 and 2007, the MarketScan database identified 342,284 patients with more than one claim for ADHD. Of these, 79,368 patients met the eligibility for the prevalence estimates. During the study period, the prevalence of diagnosed ADHD among adults increased more than three-fold: 1.24 to 4.02 cases per 1000 covered members. The largest proportion of cases was in the 18-24 years age group (42.8%-45.8% per year). Most cases were males; however, the ratio of females-to-males diagnosed increased over time. ADHD with hyperactivity was prevalent across all age groups analyzed, although more common in the 18-24 years group. Pharmacy claims showed patients receiving medical treatment for ADHD increased from 78% to 88.5%. A limitation of this study is that it is restricted to employed persons and their dependents. Thus, the results from this database may underestimate the true prevalence of diagnosed ADHD in the US population.

CONCLUSIONS

While the claims database used included employed insured persons and dependents only, study results highlight the rising prevalence of diagnosed ADHD in a US adult population. The prevalence increased more than three-fold from 2002 to 2007 with the largest increase in the 18-24 years age group. These findings on ADHD prevalence highlight the need for greater attention to the medical treatment of this disorder in different age groups, particularly in young adults.