SEARCH · PubMed Health

Results for “ADHD subtypes”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources

PubMed2001

Executive functioning and olfactory identification in young adults with attention deficit-hyperactivity disorder.

Young adults with attention deficit-hyperactivity disorder (ADHD; N = 105) were compared with a control group (N = 64) on 14 measures of executive function and olfactory identification using a 2 (group) X 2 (sex) design. The ADHD group performed significantly worse on 11 measures. No Group X Sex interaction was found on any measures. No differences were found in the ADHD group as a function of ADHD subtype or comorbid oppositional defiant disorder. Comorbid depression influenced the results of only 1 test (Digit Symbol). After IQ was controlled for, some group differences in verbal working memory, attention, and odor identification were no longer significant, whereas those in inhibition, interference control, nonverbal working memory, and other facets of attention remained so. Executive function deficits found in childhood ADHD exist in young adults with ADHD and are largely not influenced by comorbidity but may be partly a function of low intelligence.

Adolescent↗

PubMed2004

Health-related quality of life in children and adolescents who have a diagnosis of attention-deficit/hyperactivity disorder.

OBJECTIVE: The aim of treatment for attention-deficit/hyperactivity disorder (ADHD) is to decrease symptoms, enhance functionality, and improve well-being for the child and his or her close contacts. However, the measurement of treatment response is often limited to measuring symptoms using behavior rating scales and checklists completed by teachers and parents. Because so much of the focus has been on symptom reduction, less is known about other possible health problems, which can be measured easily using health-related quality-of-life (HRQL) questionnaires, which are designed to gather information across a range of health domains. The aim of our study was to measure HRQL in a clinic-based sample of children who had a diagnosis of ADHD and consider the impact of 2 clinical factors, symptom severity and comorbidity, on HRQL. Our specific hypotheses were that parent-reported HRQL would be poorer in children with ADHD than in normative US and Australian pediatric samples, in children with increasing severity of ADHD symptoms, and in children who had diagnoses of comorbid psychiatric disorders. METHODS: Cross-sectional survey was conducted in British Columbia, Canada. The sample included 165 respondents of 259 eligible children (63.7% response rate) who were referred to the ADHD Clinic in British Columbia between November 2001 and October 2002. Children who are seen in this clinic come from all parts of the province and are diverse in terms of socioeconomic status and case mix. ADHD was diagnosed in 131 children, 68.7% of whom had a comorbid psychiatric disorder. Some children had >1 comorbidity: 23 had 2, 5 had 3, and 1 had 4. Fifty-one children had a comorbid learning disorder (LD), 45 had oppositional defiant disorder or conduct disorder (ODD/CD), and 27 had some other comorbid diagnosis. The mean age of children was 10 years (standard deviation: 2.8). Boys composed 80.9% (N = 106) of the sample. We used the 50-item parent version of the Child Health Questionnaire to measure physical and psychosocial health. Physical domains include the following: physical functioning (PF), role/social limitations as a result of physical health (RP), bodily pain/discomfort (BP), and general health perception (GH). Psychosocial domains include the following: role/social limitations as a result of emotional-behavioral problems (REB), self-esteem (SE), mental health (MH), general behavior (BE), emotional impact on parent (PTE), and time impact on parents (PTT). A separate domain measures limitations in family activities (FA). There is also a single-item measure of family cohesion (FC). Individual scale scores and summary scores for physical (PhS) and psychosocial health (PsS) can be computed. Symptom severity data (parent and teacher) came from the Child/Adolescent Symptom Inventory 4. These checklists provide information on symptoms for the 3 ADHD subtypes (inattentive, hyperactive, and combined). Each child underwent a comprehensive psychiatric assessment by 1 of 4 child psychiatrists. Documentation included a full 5-axis Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnosis on the basis of a comprehensive assessment. Clinical information for each child was extracted from hospital notes. RESULTS: Compared with both population samples, children with ADHD had comparable physical health but clinically important deficits in HRQL in all psychosocial domains, FA, FC, and PsS, with effect sizes as follows: FC = -0.66, SE = -0.90, MH = -0.97, PTT = -1.07, REB = -1.60, BE = -1.73, PTE = -1.87, FA = -1.95, and PsS = -1.98. Poorer HRQL for all domains of psychosocial health, FA, and PsS correlated significantly with more parent-reported inattentive, hyperactive, and combined symptoms of ADHD. Children with > or =2 comorbid disorders differed significantly from those with no comorbidity in most areas, including RP, GH, REB, BE, MH, SE, PTT, FA, and PsS, and from those with 1 comorbid disorder in 3 domains, including BE, MH, and FA and the PsS. The mean PsS score for children in the ODD/CD group (mean difference: -12.9; effect size = -1.11) and children in the other comorbidity group (-9.0; effect size = -.77) but not children in the LD group were significantly lower than children with no comorbid disorder. Predictors of physical health in a multiple regression model included child's gender (beta = .177) and number of comorbid conditions (beta = -.197). These 2 variables explained very little variation in the PhS. Predictors of psychosocial health included the number of comorbid conditions (beta = -.374) and parent-rated combined ADHD symptoms (beta = -.362). These 2 variables explained 31% of the variation in the PsS. CONCLUSIONS: Our study shows that ADHD has a significant impact on multiple domains of HRQL in children and adolescents. In support of our hypotheses, compared with normative data, children with ADHD had more parent-reported problems in terms of emotional-behavioral role function, behavior, mental health, and self-esteem. In addition, the problems of children with ADHD had a significant impact on the parents' emotional health and parents' time to meet their own needs, and they interfered with family activities and family cohesion. The differences that we found represent clinically important differences in HRQL. Our study adds new information about the HRQL of children with ADHD in relation to symptom severity and comorbidity. Children with more symptoms of ADHD had worse psychosocial HRQL. Children with multiple comorbid disorders had poorer psychosocial HRQL across a range of domains compared with children with none and 1 comorbid disorder. In addition, compared with children with no comorbidity, psychosocial HRQL was significantly lower in children with ODD/CD and children in the other comorbidity group but not in children with an LD. The demonstration of a differential impact of ADHD on health and well-being in relation to symptom severity and comorbidity has important implications for policies around eligibility for special educational and other supportive services. Because the impact of ADHD is not uniform, decisions about needed supports should incorporate a broader range of relevant indicators of outcome, including HRQL. Although many studies focus on measuring symptoms using rating scales and checklists, in our study, using a multidimensional questionnaire, we were able to show that many areas of health are affected in children with ADHD. We therefore argue that research studies of children with ADHD should include measurement of these broader domains of family impact and child health.

Adolescent↗

PubMed2003

Child temperament, ADHD, and caregiver strain: exploring relationships in an epidemiological sample.

OBJECTIVE: To investigate the relationship between child-reported dimensions of temperament and attention-deficit/ hyperactivity disorder (ADHD), as well as other indicators of child psychopathology, including disruptive disorders, depression, and anxiety. It also examined whether difficult child temperament scores independently predicted caregiver strain. METHOD: A school-district-wide, two-phase screening design (response rate 70% for phase 2) identified elementary school children at high risk for ADHD. Two hundred high-risk children and their parents completed standardized instruments to assess child temperament, diagnoses of disruptive disorders, children's symptoms of anxiety and depression, and caregiver strain. Relationships were examined using analysis of variance, correlations, and multivariate prediction models, adjusting for child sociodemographic characteristics and psychopathology. All estimates were weighted for sampling design and differential participation. RESULTS: Combined subtype ADHD was associated with lower scores on task orientation and higher scores on general activity level. Depressive symptoms correlated significantly with all but one difficult temperament dimension, in a pattern consistent with clinical symptoms of depression. Child temperament did not vary by ADHD treatment status. Among these high-risk children, maternal caregiver strain experiences were increased by male gender, inattention symptoms, and oppositional defiant disorder, but not by difficult temperament scores. CONCLUSION: This study provides support for Graham and Stevenson's hypothesis of continuity between specific temperament traits and certain child psychiatric disorders, namely ADHD and depressive disorders.

Adult↗

PubMed1998

Addressing comorbidity in adults with attention-deficit/hyperactivity disorder.

Psychiatric comorbidity complicates the accurate diagnosis and effective treatment of attention-deficit/hyperactivity disorder (ADHD) in adults. This paper examines the influence of comorbidity on treatment responsiveness in ADHD adults, the neurobiological underpinnings of comorbidity, and the potential of different pharmacologic agents to address comorbid states in ADHD. A categorical schema for neurobiological classification of ADHD subtypes is integrated with literature associating specific neurotransmitters with corresponding neurobehavioral abnormalities. Dopamine, for example, is one of several neurotransmitters implicated in bipolar disorder. Serotonin and norepinephrine are implicated in major depression and anxiety disorders, while self-medication for dopamine dysfunction may relate to substance abuse. Norepinephrine and serotonin have each been linked to aggression and impulsive antisocial behaviors. The effective treatment of ADHD with comorbid psychiatric disorders requires knowledge of the neurochemical underpinnings of each disorder and expertise in the application of appropriate pharmacologic tools. Controlled studies assessing treatment outcomes for both comorbid disorders will assist in the development of improved treatment strategies for adults with complicated ADHD.

Adolescent↗

PubMedDate not supplied

Seasonal affective symptoms in adults with residual attention-deficit hyperactivity disorder.

There is evidence from clinical, epidemiological, and neuroimaging studies that attention-deficit hyperactivity disorder (ADHD) and seasonal affective disorder (SAD) may have several features in common. To assess seasonal affective symptoms in adults with ADHD, 115 individuals attending an adult ADHD clinic in Toronto, Ontario, Canada were asked to complete the Seasonal Pattern Assessment Questionnaire (SPAQ). From this clinic population of 115, a total of 56 completed SPAQs were returned. Assuming that all individuals failing to complete the SPAQ were nonseasonal and depending on which case-finding criteria were used, the rate of SAD in the overall clinic sample was estimated at either 10.4% (Terman criteria) or 19.1% (criteria of Kasper et al.). These prevalence rates are significantly greater than the rates reported in large population surveys at similar latitudes. There was an apparent relationship between female gender, impulsive-subtype ADHD, and seasonality. Future studies to examine whether core symptoms of ADHD fluctuate across the seasons and to assess the efficacy of light therapy in "seasonal" ADHD patients would be of great theoretical and clinical interest.

Adolescent↗

PubMed2005

12-month efficacy and safety of OROS MPH in children and adolescents with attention-deficit/hyperactivity disorder switched from MPH.

PURPOSE: The aim of this study was to evaluate long-term clinical treatment with OROS methylphenidate (MPH) (Concerta) in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) who had been previously treated with immediate release (IR) MPH. METHODS: Subjects aged 6-16 years (n=105) who were stable on IR MPH (10-60 mg/day) were switched to 18, 36 or 54 mg OROS MPH once daily for 21 days, depending on prestudy MPH dose. Subjects who benefited from OROS MPH could continue in a 12-month extension period. ADHD symptoms and treatment response were assessed by parents/caregivers and investigators. RESULTS: Out of 105 enrolled children, 101 completed the 21-day treatment phase. In all, 89 parents/caregivers (88.1%) wanted their child to continue with the study treatment into the extension phase, and 56 children (63 %) completed the 1-year trial. The parent/caregiver global assessment of satisfaction ranged from 49 to 69% during the extension phase, and 49 to 71% of investigators rated the treatment as adequate. Efficacy and satisfaction were found more commonly in patients in the older age group (10-16 years), those on a higher dose (36 mg or 54 mg) and with the predominantly inattentive ADHD subtype. OROS MPH was well tolerated. CONCLUSIONS: Children and adolescents can effectively and safely be switched from IR MPH to OROS MPH with improved symptom control and compliance.

Adolescent↗

PubMed2004

Age-dependent expression of attention-deficit/hyperactivity disorder symptoms.

The authors' research indicates that most adults with ADHD continue to struggle with substantial number of ADHD symptoms and high levels of dysfunction despite a sizable syndromatic remission. Furthermore, in-attention was more persistent than hyperactivity or impulsivity as children progress throughout adolescence and into early adulthood. These results stress the critical importance of carefully choosing the appropriate definition of remission in longitudinal studies of youth with ADHD and that symptom clusters and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-defined ADHD subtypes (ie, combined, inattentive., or hyperactive/'impulsive) should be considered separately.

Age Factors↗

PubMed2001

Is ADHD a disinhibitory disorder?

Attention deficit hyperactivity disorder (ADHD) is widely theorized to stem from dysfunctional inhibitory processes. However, the definition of inhibition is imprecisely distinguished across theories. To clarify the evidence for this conception, the author relies on a heuristic distinction between inhibition that is under executive control and inhibition that is under motivational control (anxiety or fear). It is argued that ADHD is unlikely to be due to a motivational inhibitory control deficit, although suggestions are made for additional studies that could overturn that conclusion. Evidence for a deficit in an executive motor inhibition process for the ADHD combined type is more compelling but is not equally strong for all forms of executive inhibitory control. Remaining issues include specificity to ADHD, whether inhibitory problems are primary or secondary in causing ADHD, role of comorbid anxiety and conduct disorder, and functional deficits in the inattentive ADHD subtype.

Anxiety Disorders↗

PubMed2007

The latent structure of attention-deficit/hyperactivity disorder in a clinic-referred sample.

The question of whether attention-deficit/hyperactivity disorder (ADHD) represents a continuum of attentional and executive dysfunction or a natural category has yet to be extensively investigated. Subjective report and neuropsychological data from 437 individuals referred for neuropsychological evaluation were analyzed using latent class and taxometric analyses (mean above minus below a cut [MAMBAC], maximum eigenvalue [MAXEIG], and latent mode [LMODE]). Results indicated no significant evidence for a taxonic representation of ADHD across multiple procedures and indicator sets. Similarly, there was no evidence that ADHD subtypes represent a qualitative distinction. These findings may suggest that current diagnostic conceptualizations are inadequate for accurately identifying and characterizing individuals with problems related to attention and executive dysfunction. Alternatively, the null findings may have resulted from inadequate indicator selection. A dimensional model may better facilitate accurate identification of individuals at risk for functional impairment.

Adolescent↗

PubMed1998

Clinical and treatment characteristics of children with attention-deficit/hyperactivity disorder in psychiatric practice.

OBJECTIVE: To capture information about the clinical characteristics of, and treatments for, children with attention-deficit/hyperactivity disorder (ADHD) in psychiatric practice. METHOD: A mailed, self-administered questionnaire was sent to 81 practicing psychiatrists for them to complete on the next three consecutive patients aged 14 years and younger with ADHD seen during the 12-day study period. Information collected included the sociodemographic, clinical, and treatment characteristics of sampled patients. RESULTS: Patients in the study were predominantly white (85%), male (78%), and between 10 and 14 years old (58%). The most common ADHD subtype was combined/predominantly hyperactive (86%); 31% had no other comorbidity. Ninety-seven percent were receiving medications, with 49% receiving two or more. The single most common medication reported was methylphenidate (51% of patients) followed by clonidine (20%). Psychotropics other than psychostimulants were used in a majority of patients (55%). CONCLUSIONS: Psychiatrists, and child and adolescent psychiatrists in particular, see a more severely impaired and complex group of patients than would be expected of primary care providers. The treatment patterns of psychiatrists for these patients do not reflect the simpler treatments usually studied in clinical trials.

Adolescent↗

PubMed2002

Sluggish cognitive tempo predicts a different pattern of impairment in the attention deficit hyperactivity disorder, predominantly inattentive type.

Compared 2 groups of children with attention deficit hyperactivity disorder, predominantly inattentive type (ADHD/IA)--those with high scores on a composite measure of sluggish cognitive tempo (SCT) and those without--using a large, school-based sample of children for which previous comparisons between ADHD subtypes have been reported. Although the 2 groups did not differ on level of attention or learning problems, high-SCT ADHD/IA children were rated by teachers as showing less externalizing behavior and higher levels of unhappiness, anxiety/depression, withdrawn behavior, and social dysfunction. Thus, SCT identifies a more homogeneous subgroup of ADHD/IA children who are, relative to the entire Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]; American Psychiatric Association [APA], 1994) diagnosed ADHD/IA group, more similar to those classified in previous research as "attention deficit disorder without hyperactivity." These results support a reconsideration of SCT symptoms as a component of diagnostic criteria for a category of nonhyperactive attention deficit disorder.

Anxiety↗

PubMed2004

[Epidemiological study on symptoms of attention deficit/hyperactivity disorder and behavior disorders in public schools of Florianopolis/SC using the EDAH].

OBJECTIVE: Attention deficit/hyperactivity disorder (ADHD) is a pathology characterized by inattention, hyperactivity and impulsivity. The purpose of this article is to conduct an epidemiological study on symptoms of ADHA and behavior disorders in public schools of Florianopolis/SC. METHOD: The study involved 1,898 students (1,001 males and 897 females) enrolled in five public schools of Florianopolis, from the 1st up to the 4th grades, aged 6 to 12. The instrument used was the EDAH, filled out by teachers and parents, which classifies children with predominance of the following symptoms: hyperactivity, attention deficit, conduct disorder, hyperactivity with attention deficit and ADHD associated with conduct disorder (global). RESULTS: Of the 1,898 students, 95 (5%) showed symptoms of ADHA associated with behavioral disorders. Regarding gender, the prevalence was higher in boys, in a 3:1 ratio. CONCLUSION: Our data is in accordance with the literature. The distribution of the ADHD subtypes by gender is similar to the mentioned literature.

Attention Deficit Disorder with Hyperactivity↗

PubMed1999

Childhood conduct problems, hyperactivity-impulsivity, and inattention as predictors of adult criminal activity.

This study reconsiders the relationship of childhood Attention Deficit/Hyperactivity Disorder (ADHD) and childhood conduct problems with adult criminal activity by clarifying the role of the cardinal behaviors associated with the DSM-IV ADHD subtypes (inattention and hyperactivity/impulsivity). Since their childhood (average age 9 years), 230 male and 75 female subjects have been followed prospectively and were interviewed as young adults (average age 26 at follow-up). Early childhood behavior ratings by parents and teachers were examined to determine the role of conduct problems, hyperactivity-impulsivity, and inattention in predicting adult criminal involvement as measured by both official arrest records and self-report. Results show that both hyperactivity-impulsivity and early conduct problems independently, as well as jointly, predict a greater likelihood of having an arrest record for males, but not for females. For male subjects with 10 or more self-reported crimes, both early conduct problems and hyperactivity-impulsivity were significant predictors, both alone and in combination. Therefore, it appears that predominantly the symptoms of hyperactivity-impulsivity, but not inattention, contribute to the risk for criminal involvement over and above the risk associated with early conduct problems alone.

Adult↗

PubMed1997

Comorbidity in ADHD: implications for research, practice, and DSM-V.

OBJECTIVE: Since the introduction of DSM-III/III-R, clinicians and investigators have shown increasing interest in the study of conditions comorbid with attention-deficit hyperactivity disorder (ADHD). Better understanding ADHD comorbidity patterns is needed to guide treatment, research and future classification approaches. METHOD: The ADHD literature from the past 15 years was reviewed to (1) explore the most prevalent patterns of ADHD comorbidity; (2) examine the correlates and longitudinal predictors of comorbidity; and (3) determine the extent to which comorbid patterns convey unique information concerning ADHD etiology, treatment and outcomes. To identify potential new syndromes, the authors examined comorbid patterns based on eight validational criteria. RESULTS: The largest available body of literature concerned the comorbidity with ADHD and conduct disorder/aggression, with a substantially smaller amount of data concerning other comorbid conditions. In many areas the literature was sparse, and pertinent questions concerning comorbidity patterns remain unexplored. Nonetheless available data warrant the delineation of two new subclassifications of ADHD: (1) ADHD aggressive subtype, and (2) ADHD, anxious subtype. CONCLUSIONS: Additional studies of the frequency of comorbidity and associated factors are greatly needed to include studies of differential effects of treatment of children with various comorbid ADHD disorders, as well as of ADHD children who differ on etiological factors.

Aggression↗

PubMed2005

Variability in time reproduction: difference in ADHD combined and inattentive subtypes.

OBJECTIVE: To examine the relationship between time reproduction, performance variability, and sustained attention deficits in children with attention-deficit/hyperactivity disorder (ADHD) combined (ADHD-C) and inattentive (ADHD-I) subtypes, relative to matched controls. METHOD: Participants (age range 7.1-14.1 years) performed a time reproduction task. A subset of the ADHD group was also tested on the Sustained Attention to Response Test. Absolute discrepancy, accuracy coefficient, and intraindividual variability scores on the time reproduction task were compared across the three groups (ADHD-C: N = 20; ADHD-I: N = 19; controls: N = 44) and correlated with the Sustained Attention to Response Test. RESULTS: First, significantly better performance was observed in matched controls than in children with ADHD on the time reproduction task. Second, there was a significant difference between the two ADHD subtypes in the variability of the size of errors made at high time intervals (36-60 seconds). Third, intraindividual performance variability in the direction (over- versus underestimations) of time reproductions correlated with sustained attention performance. CONCLUSIONS: Children with ADHD varied more in the size and direction of their time reproduction errors than control children. Those with ADHD-C demonstrated more intraindividual variability than did those with ADHD-I in the size of their errors. The data provide support for a relationship between sustained attention and time reproduction. This relationship has previously been inferred from common right-lateralized neural circuitry that is thought to subserve these processes.

Adolescent↗

PubMed2006

Family psychiatric history evidence on the nosological relations of DSM-IV ADHD combined and inattentive subtypes: new data and meta-analysis.

BACKGROUND: A key issue in the nosology of attention deficit hyperactivity disorder (ADHD) has concerned whether the DSM-IV combined (ADHD-C) and primarily inattentive (ADHD-PI) subtypes are in fact distinct disorders, or instead are fairly closely related, perhaps differing only in severity. Pertinent to this question, but in short supply, are data on family psychiatric history. METHOD: We present new data followed by a meta-analysis. For the new data 210 children were well-characterized via structured interview and multi-informant ratings as ADHD-C or ADHD-PI. Three hundred and thirty-five parents completed structured diagnostic interviews to determine whether they had ADHD-C or ADHD-PI. Comorbid disorders were also assessed. For the meta-analysis, 6 existing family-history data sets using DSM-IV subtypes were pooled and analyzed (total N = 4120). RESULTS: The new family study found support for subtype-specific transmission, but the effect was small. Girls with ADHD-C had more severe family psychiatric histories (non-ADHD disorders in parents) than girls with ADHD-I, but this subtype effect did not occur for boys. The meta-analysis of 6 data sets implemented a model-fitting methodology. Despite inconsistent results across individual studies, the pooled data consistently suggested that (1) some degree of subtype specific transmission is occurring, (2) the effect is small, (3) non-specific (gradient) transmission also occurs, specifically in families of children with ADHD-C. CONCLUSION: The much-debated relation between these two most prevalent ADHD subtypes is best modeled via two processes transmitting in families. One process is distinct for the two syndromes, and the other is shared. We briefly suggest neuropsychological models that would account for this state of affairs and suggest future research to refine the nosology with these findings in mind.

Adult↗

PubMedDate not supplied

Right hemisphere dysfunction in ADHD: visual hemispatial inattention and clinical subtype.

The relationship between right hemisphere dysfunction and attention-deficit/hyperactivity disorder (ADHD) remains controversial. We administered a random letter cancellation test to 58 carefully selected adult patients meeting DSM-IV criteria for ADHD and 29 age- and education-matched controls. Patients with ADHD had a higher mean omission rate on the left side than the controls, and a greater percentage of ADHD patients than controls made more omissions on the left than on the right (L > R errors). ADHD patients who made L > R errors had lower performance IQ scores than ADHD patients who did not make L > R errors. However, ADHD patients who made L > R errors did not differ from ADHD patients who did not make L > R errors in ADHD subtype, medication response, or neuropsychological measures of attention, executive function, verbal memory, nonverbal memory, or academic achievement. Patients without a family history of ADHD were more likely to make L > R errors than patients with a family history of ADHD. This study provides support for the concept of right hemisphere dysfunction in a subset of patients with ADHD. However, ADHD patients who make L > R errors do not appear to represent a distinct clinical subgroup in terms of medication response, ADHD subtype, or neuropsychological test performance.

Adult↗

PubMed2006

Working memory deficits in adults with ADHD: is there evidence for subtype differences?

BACKGROUND: Working memory performance is important for maintaining functioning in cognitive, academic and social activities. Previous research suggests there are prevalent working memory deficits in children with attention deficit hyperactivity disorder (ADHD). There is now a growing body of literature characterizing working memory functioning according to ADHD subtypes in children. The expression of working memory deficits in adults with ADHD and how they vary according to subtype, however, remains to be more fully documented. METHODS: This study assessed differences in working memory functioning between Normal Control (NC) adults (N = 18); patients with ADHD, Combined (ADHD-CT) Type ADHD (N = 17); and ADHD, Inattentive (ADHD-IA) Type (N = 16) using subtests from the Wechsler Adult Intelligence Scale-III and Wechsler Memory Scale-III and the Paced Auditory Serial Addition Task (PASAT). RESULTS: The ADHD groups displayed significant weaknesses in contrast to the NC group on working memory tests requiring rapid processing and active stimulus manipulation. This included the Letter-Number-Sequencing test of the Wechsler scales, PASAT omission errors and the longest sequence of consecutive correct answers on the PASAT. No overall ADHD group subtype differences emerged; however differences between the ADHD groups and the NC group varied depending on the measure and the gender of the participants. Gender differences in performance were evident on some measures of working memory, regardless of group, with males performing better than females. CONCLUSION: In general, the data support a dimensional interpretation of working memory deficits experienced by the ADHD-CT and ADHD-IA subtypes, rather than an absolute difference between subtypes. Future studies should test the effects of processing speed and load on subtype performance and how those variables interact with gender in adults with ADHD.

Journal Article↗