Memory in Early Onset Bipolar Disorder and Attention-Deficit/Hyperactivity Disorder: Similarities and Differences

Differentiating between early-onset bipolar disorder (BD) and attention-deficit/hyperactivity disorder (ADHD) can be difficult. Memory problems are commonly reported in BD, and forgetfulness is among the diagnostic criteria for ADHD. We compared children and adolescents with BD (n?=?23), ADHD combined type (ADHD-C; n?=?26), BD?+?ADHD-C (n?=?15), and 68 healthy controls on memory tests (Digit span, Children's Verbal Learning Test-II). Further analyses were performed on subgroups of BD (BD-I, BD-II/BD-NOS, with and without previous psychotic symptoms). All clinical groups demonstrated some problems with free recall, but the BD subgroup with a history of psychotic symptoms had a more pervasive problem that also included recognition and semantic clustering. The ADHD-C groups demonstrated the lowest performance on working memory. These data suggest that children and adolescents with BD and previously psychotic symptoms may have inefficient encoding of verbal material, whereas memory problems in ADHD-C appear more characterized by impaired free recall.     

Components of Visual Search in Childhood-Onset Schizophrenia and Attention-Deficit/Hyperactivity Disorder

This study tested the hypotheses that visual search impairments in schizophrenia are due to a delay in initiation of search or a slow rate of serial search. We determined the specificity of these impairments by comparing children with schizophrenia to children with attention-deficit hyperactivity disorder (ADHD) and age-matched normal children. The hypotheses were tested within the framework of feature integration theory by administering children tasks tapping parallel and serial search. Search rate was estimated from the slope of the search functions, and duration of the initial stages of search from time to make the first saccade on each trial. As expected, manual response times were elevated in both clinical groups. Contrary to expectation, ADHD, but not schizophrenic, children were delayed in initiation of serial search. Finally, both groups showed a clear dissociation between intact parallel search rates and slowed serial search rates.     

Attention-Deficit Hyperactivity Disorder: The Medicalization of Misbehavior

During the past decade, there has been an increase in the diagnosis and treatment of Attention-Deficit Hyperactivity Disorder (ADHD). This syndrome, typically diagnosed in childhood, is characterized by inattention, hyperactive motor behavior, and distractibility. Current prevalence rates obtained in various countries generally exceed the 3–5% reported by DSM-IV. Reasons for increased ADHD prevalence include changes in diagnostic standards, overlap between ADHD and other externalizing disorders, nonspecific behavioral criteria, and the rapid effects of stimulant medication on cognitive functioning. However, social, cultural, and economic factors may also contribute to increased diagnosis. ADHD has become a common topic in the lay media. Popular discussions of ADHD may serve as a metaphoric expression of social anxieties, particularly with respect to children. At the same time, ADHD has rapidly become incorporated into a medical model, with emphasis on pharmacological treatment. Reductions in mental health and educational services, as well as economic pressures of managed care, may also contribute to medicalization of behavioral problems. Collaboration between psychologists and primary care physicians can lead to more accurate diagnosis and appropriate treatment of ADHD and related disorders.     

Paired-Associate Learning in Attention-Deficit/Hyperactivity Disorder as a Function of Hyperactivity-Impulsivity and Oppositional Defiant Disorder

A paired-associate learning (PAL) test was administered to 22 community volunteers without disruptive disorders and 197 children (7.5–13.5 years-old) presenting with the inattentive and combined subtypes of attention-deficit/hyperactivity disorder (ADHD) either in combination with or without oppositional defiant disorder (ODD). Participants were screened for learning disorders. In comparison to non-ADHD participants, children with ADHD achieved worse PAL and made errors rated as more acoustically and less semantically similar to the correct paired associates. These deficits were not related to hyperactivity–impulsivity or comorbid ODD. These results suggest that ADHD children are less competent at PAL and use less efficient learning strategies than their non-ADHD peers.     

Overlapping and Distinct Cognitive Impairments in Attention-Deficit/Hyperactivity and Autism Spectrum Disorder without Intellectual Disability

Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are commonly comorbid, share genetic liability, and often exhibit overlapping cognitive impairments. Clarification of shared and distinct cognitive effects while considering comorbid symptoms across disorders has been lacking. In the current study, children ages 7–15 years assigned to three diagnostic groups:ADHD (n?=?509), ASD (n?=?97), and controls (n?=?301) completed measures spanning the cognitive domains of attention/arousal, working memory, set-shifting, inhibition, and response variability. Specific processes contributing to response variability were examined using a drift diffusion model, which separately quantified drift rate (i.e., efficiency of information processing), boundary separation (i.e., speed-accuracy trade-offs), and non-decision time. Children with ADHD and ASD were impaired on attention/arousal, processing speed, working memory, and response inhibition, but did not differ from controls on measures of delayed reward discounting, set-shifting, or interference control. Overall, impairments in the ASD group were not attributable to ADHD symptoms using either continuous symptom measures or latent categorical grouping approaches. Similarly, impairments in the ADHD group were not attributable to ASD symptoms. When specific RT parameters were considered, children with ADHD and ASD shared impairments in drift rate. However, children with ASD were uniquely characterized by a wider boundary separation. Findings suggest a combination of overlapping and unique patterns of cognitive impairment for children with ASD as compared to those with ADHD, particularly when the processes underlying reaction time measures are considered separately.     

Interrelationships between Reading Disability and Attention-Deficit/Hyperactivity Disorder

Evidence from a number of investigations suggests a considerable overlap between reading disability (RD) and attention deficit-hyperactivity disorder (ADHD). We investigate the relationship between RD and ADHD in a cohort of 186 children 7.5–9.5 years of age, recruited explicitly to address classification and definitional issues in these disorders. Using multivariate methods, we examine the hypothesis that RD and ADHD represent separate diagnostic entities that frequently co-occur in the same individual. The results suggest that RD is characterized by deficits within the language system, in particular a subcomponent within that system, phonological processing; in contrast, such linguistic deficits are not characteristic of ADHD unless ADHD is associated with RD. When children with both RD and ADHD are examined, both the linguistic deficits associated with RD and the behavioral characteristics associated with ADHD are apparent, but these deficits are not synergistic. We conclude that RD and ADHD represent separate disorders that frequently co-occur.     

Attention-Deficit/Hyperactivity Disorder: A Neuropsychological Perspective Towards DSM-V

Neuropsychological methods and techniques have much to offer in the evaluation of the individual suspected as having Attention-Deficit/Hyperactivity Disorder (ADHD). After a review of the historical evolution of the ADHD concept, incidence and prevalence, and DSM-IV criteria for diagnosis, especially as regards omission related to gender differences, and other associated cultural, familial, socioenvironmental, and subject influences, this paper describes a number of dilemmas and obstacles encountered in clinical practice. Included are the confounds associated with the wide range of possible comorbidities, the insufficiency of current DSM-IV criteria, the emergence of subtype differentiation and its impact on diagnosis and treatment. The complex relationship between neuropsychological constructs and ADHD, and obstacles to valid assessment are also addressed. The complexities associated with a thorough ADHD evaluation are viewed within an impressive and expansive existing scientific framework and recommendations are made for future directions.     

Methylphenidate in treatment of adults with Attention-Deficit/Hyperactivity Disorder

Attention-Deficit/Hyperactivity Disorder (ADHD) can persist into adulthood with a continuation of the pattern of childhood psychopathology, cognition and functioning. Adult comorbidities include substance use disorders, antisocial personality disorder, anxiety, and depression. Studies have shown that as in children, methylphenidate treatment for adults can lead to a robust, dose-dependent improvement in ADHD symptoms. Future research is needed to evaluate the safety and efficacy of long-term treatment with methylphenidate (MPH).     

Forty years of methylphenidate treatment in Attention-Deficit/ Hyperactivity Disorder

This paper reviews approximately 40 years of stimulant drug treatment of children with behavior and learning problems. These patients generally fall under the rubric of Attention-Deficit/Hyperactivity Disorder (ADHD), with core symptoms of hyperactivity, impulsivity, and inattention being the most studied and most robust of the targets for stimulant treatment. In addition, the drug effects on other targets, such as cognitive and academic function, are included. The largest selection of studies involves methylphenidate. Both qualitative studies and meta-analytic studies from major reviews are examined. Variations in the methodology of the reviews are described and some of the discrepancies in interpretation examined. Despite wide variations in subject selection, types of trials, degree of methodological rigor, and the decade in which the studies took place, the evidence is remarkably consistent The overall results suggest significant clinical impact upon the core features of ADHD. More studies of long-term effects and special populations such as older adolescents and adults will be necessary, though existing evidence strongly supports similar findings as for the younger patients with a diagnosis of ADHD.     

Efficacy of Adderall for Attention-Deficit/Hyperactivity Disorder: a meta-analysis

Stimulant medication has, for many years, been the pharmacological treatment of choice for children and adults with Attention-Deficit/Hyperactivity Disorder (ADHD). Several studies have shown Adderall , to be efficacious for measures of inattention, hyperactivity-impulsivity, aggression, disruptive behavior, and academic productivity. Although these studies provide useful information for clinicians treating ADHD children and adults, the variability in efficacy among the different types of measures used within each study has not been comprehensively examined. Thus, to provide a clearer picture of what conclusions can be drawn from these studies, we performed a meta-analysis. Data from the six available studies of standard release Adderall show it to be efficacious for symptoms of inattention, hyperactivity-impulsivity, and aggression, as well as global ratings. Its efficacy was significant for clinician, parent, and teacher ratings, and for both fixed- and best-dose designs.     

Associations between Maternal Attention-Deficit/Hyperactivity Disorder Symptoms and Parenting

Mothers of children with attention-deficit/hyperactivity disorder (ADHD) are at increased risk for an ADHD diagnosis themselves, which is likely associated with impairments in parenting. The present study utilized a multi-method assessment of maternal ADHD and parenting to examine the extent to which maternal ADHD symptoms are associated with maladaptive parenting. Participants included 70 6–10 year old children with DSM-IV ADHD and their biological mothers. Results suggested that mothers with higher levels of ADHD symptoms reported lower levels of involvement and positive parenting and higher levels of inconsistent discipline. During observed parent–child interactions, maternal ADHD symptoms were negatively associated with positive parenting, and positively associated with negative parenting and repeated commands before giving the child an opportunity to comply. Given prior research suggesting that maladaptive parenting behaviors are risk factors for the later development of conduct problems among children with ADHD, these findings have important clinical implications for family-based assessment and treatment of ADHD.     

Mother-Child Relationship in Youths with Attention-Deficit Hyperactivity Disorder and their Siblings

Despite impaired mother-child interactions noted in youth with attention-deficit/hyperactivity disorder (ADHD), there is no such information for their siblings. This study aimed to test whether the affected and unaffected siblings, like youth with ADHD, also encountered impaired mothering and mother-child relationships as compared to typically developing youth (TD). The sample consisted of 122 probands (107 males, 87.7 %), aged 10–16, with DSM-IV ADHD, 44 affected (26 males, 59.1 %) and 78 unaffected (28 males, 35.9 %) siblings, and 122 TD youth. Both participants and their mothers received psychiatric interviews (K-SADS-E) about the participants and reported maternal parenting style, mother-child interactions and child behavioral problems at home. Based on both reports, probands with ADHD and affected siblings (only youth report) had more impaired relationships, more behavioral problems at home, and less perceived family support than unaffected siblings and TD youth. Probands with ADHD had higher maternal authoritarian control than unaffected siblings. The findings suggest that impaired mothering, mother-child interactions, and family support are related to the presence of ADHD diagnosis in both probands and their affected siblings.     

A Comparison of Structural Brain Imaging Findings in Autism Spectrum Disorder and Attention-Deficit Hyperactivity Disorder

ASD and ADHD are regarded as distinct disorders in the current DSM-5. However, recent research and the RDoC initiative are recognizing considerable overlap in the clinical presentation of ASD, ADHD, and other neurodevelopmental disorders. In spite of numerous neuroimaging findings in ASD and ADHD, the extent to which either of the above views are supported remains equivocal. Here we compare structural MRI and DTI literature in ASD and ADHD. Our main findings reveal both distinct and shared neural features. Distinct expressions were in total brain volume (ASD: increased volume, ADHD: decreased volume), amygdala (ASD: overgrowth, ADHD: normal), and internal capsule (ASD: unclear, ADHD: reduced FA in DTI). Considerable overlap was noted in the corpus callosum and cerebellum (lower volume in structural MRI and decreased FA in DTI), and superior longitudinal fasciculus (reduced FA in DTI). In addition, we identify brain regions which have not been studied in depth and require more research. We discuss relationships between brain features and symptomatology. We conclude by addressing limitations of current neuroimaging research and offer approaches that account for clinical heterogeneity to better distinguish brain-behavior relationships.     

Current concepts on the neurobiology of Attention-Deficit/Hyperactivity Disorder

Attention-Deficit/Hyperactivity Disorder (ADHD) is an early onset, clinically heterogeneous disorder of inattention, hyperactivity, and impulsivity. In contrast to the widespread acceptance of ADHD as a childhood diagnosis, Its prevalence In adults and its implications for clinical practice remain a source of controversy. Throughout the lifecycle, a key clinical feature observed in ADHD patients is comorbidity with Conduct Depressive, Bipolar, and Anxiety disorders. Family studies consistently support the assertion that ADHD runs in families. Heritability data from twin studies of ADHD attribute about 80 percent of the etiology of ADHD to genetic factors. Adoption studies of ADHD also implicate genes in its etiology. Molecular genetic data are bolstered by considerations suggesting that DRD4 and DAT genes may be relevant for ADHD. Independently of genes, prenatal exposure to nicotine and psychosocial adversity have also been identified as risk factors for ADHD. Structural and functional imaging studies consistently implicate catecholamine-rich fronto-subcortical systems in the pathophysiology of ADHD. The effectiveness of stimulants, along with animal models of hyperactivity, point to catecholamine disruption as at least one source of ADHD brain dysfunction. Although not entirely sufficient, changes in dopaminergic and noradrenergic function appear necessary for the clinical efficacy of pharmacological treatments for ADHD, providing support for the hypothesis that alteration of monoaminergic transmission in critical brain regions may be the basis for therapeutic action in ADHD.     

Personality Mediation of Genetic Effects on Attention-Deficit/Hyperactivity Disorder

Personality traits may be viable candidates for mediators of the relationship between genetic risk and ADHD. Participants were 578 children (331 boys; 320 children with ADHD) between the ages of six and 18. Parents and teachers completed a comprehensive, multi-stage diagnostic procedure to assess ADHD and comorbid disorders. Mother completed the California Q-Sort to assess child Big Five personality traits. Children provided buccal samples of DNA which were assayed for selected markers on DRD4, DAT1, and ADRA2A. An additive genetic risk composite was associated with ADHD symptoms and maladaptive personality traits; maladaptive personality traits were associated with ADHD symptoms. Low conscientiousness and high neuroticism partially mediated the relationship between genetic risk and ADHD symptoms. Mediation effects for conscientiousness were specific to inattentive symptoms; effects for neuroticism generalized to all disruptive behaviors. High neuroticism and low conscientiousness may be useful as early markers for children at risk for ADHD.