Mindfulness and attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a disorder characterized by attentional difficulties. Mindfulness is a receptive attention to present experience. Both ADHD and mindfulness are associated with attention and personality. This study tests whether individuals with ADHD have lower mindfulness scores than controls and, if true, whether personality contributes to these differences. One hundred and five adults (half with ADHD) were assessed for mindfulness, using the Kentucky Inventory of Mindfulness Skills, and personality, using the Tridimensional Character Inventory. Individuals with ADHD report themselves as less mindful than non‐ADHD controls and more novelty‐seeking, less self‐directed, and more self‐transcendent. Mindfulness is negatively associated with ADHD and positively associated with self‐directedness and self‐transcendence. Analyses of subscales of mindfulness suggest that ADHD is associated most with the “Acting in Awareness” dimension, perhaps because of shared items reflecting attentional variability. The current findings support that a large portion of variability in trait mindfulness can be explained by ADHD status and personality traits of self‐directedness and self‐transcendence. It further suggests that interventions that increase mindfulness might improve symptoms of ADHD and increase self‐directedness and/or self‐transcendence. © 2009 Wiley Periodicals, Inc. J Clin Psychol 65: 1–12, 2009.     

Diversity and attention deficit hyperactivity disorder

Attention Deficit Hyperactivity Disorder (ADHD) is a debilitating disorder which affects children and adults in this country and around the world. Diversity variables such as ethnicity, age, gender, and socioeconomic status have been relatively neglected in ADHD research. Additionally, these variables have not traditionally been incorporated into clinical assessment, diagnosis, or intervention strategies. A review of the existing literature regarding diversity issues and ADHD was conducted, including a review of international findings. Implications for clinicians and researchers are incorporated. © 1998 John Wiley & Sons, Inc. J Clin Psychol 54: 415–426, 1998.     

Dopamine system genes and attention deficit hyperactivity disorder: a meta-analysis

The dopamine system may play a major role in the development of attention deficit hyperactivity disorder (ADHD). We applied a random-effects model meta-analysis to family-based studies of association between ADHD and the dopamine system genes DRD4, DRD5 and DAT1. A statistical test of heterogeneity was conducted for each group of studies. The meta-analysis of DRD4 included data from 13 studies, with a total of 571 informative meioses. The pooled odds ratio estimate was 1.41 (95% CI 1.20-1.64, =1.57 x 10 ), demonstrating positive association. For DRD5, data from five studies, with a total of 340 informative meioses, were combined yielding a pooled odds ratio of 1.57 (95% CI 1.25-1.96, =8.28 x 10 ). Eleven studies examining DAT1, with a total of 824 informative meioses, yielded a non-significant pooled odds ratio estimate of 1.27 (95% CI 0.99-1.63, 0.06). There was no support of heterogeneity between the studies. Overall, the meta-analyses support the involvement of the dopamine system genes in ADHD liability variation and suggest the need for studies examining interactions between these genes.     

Searching for the attention deficit in attention deficit hyperactivity disorder: the case of visuospatial orienting

We review all 14 extant studies of covert visuospatial attention in attention deficit hyperactivity disorder (ADHD) (total N=248). Metaanalysis showed that intriguing but isolated findings of alerting or posterior disengage deficits were too small to reliably detect with the sample sizes typically employed. Posterior move and engage operations and the vigilance sustained attention process were normal in ADHD. For exogenous cues, effect sizes for group differences were homogeneously small across all repeated-measures conditions, as were calculations of cost, benefit, and validity effects. For endogenous cues, effect sizes were heterogeneous; however, calculations of cost, benefit, and validity effects were small and homogenous. The most parsimonious conclusion may be that ADHD is not characterized by significant visual orienting dysfunction, but questions remain about the extent of anterior lateralized effects in the combined subtype and about attentional functioning in the inattentive subtype.     

Segregation analysis of attention deficit hyperactivity disorder

We performed segregation analysis on 495 nuclear families, ascertained for the father's substance abuse diagnosis, in an attempt to determine the role of genetic and other influences in determining the variability of DSM-III-R-defined attention deficit hyperactivity disorder (ADHD). For our analyses, ADHD was treated as a quantitative variable, utilizing the semicontinuous scale provided by the 15-item symptom count within DSM-III-R. Analyses consisted of both class A and class D regressive models for which covariate effects (socioeconomic status) and sex dependence were estimated. Segregation analysis of the quantitative trait (ADHD symptom count) in the entire data set supported a transmissible non-Mendelian major effect. Models which were sex-dependent and included covariate effects provided the best fit to the data. In addition, similar analyses were performed on a 130-nuclear family subgroup of the data set in which at least one of the members of the nuclear family met DSM-III-R diagnostic criteria for ADHD. The sex-dependent Mendelian codominant model was best supported by the data, while other models could be rejected. Incorporating covariate effects did not provide a better fit for the data. Thus, this study is consistent with Mendelian transmission of ADHD symptom count in a clinically relevant population. Overall, our results support the presence of a heritable continuous trait of which ADHD represents an extreme.     

Collicular dysfunction in attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder characterised by (inter alia) an increase in distractibility. The current front-line pharmacotherapies for the treatment of ADHD, namely the psychostimulants methylphenidate and amphetamines, have clear abuse potential, hence there is a strong need to develop new drug treatments for this disorder. Central to this process is the identification of the pathophysiological changes which underlie ADHD. Given the heterogeneity of the disorder, multiple loci are probably involved, providing multiple potential therapeutic targets. Here, we hypothesise (Hypothesis 1) that one such locus is the superior colliculus (SC), a sensory structure intimately linked with distractibility and the production of eye and head movements. It is proposed that in ADHD, the colliculus is hyper-responsive, leading to the core symptom of increased distractibility. Hypothesis 1 is supported by: 1. ADHD patients show increased distractibility in tasks which are sensitive to collicular function; 2. ADHD patients have a general problem inhibiting saccades, the generation of which involves the SC; 3. Saccadic deficits in ADHD include defects in the production of saccadic types (anti-saccades and express saccades) which are particularly associated with the colliculus; 4. Covert shifts in attention (which also have been argued to involve the SC) are also impaired in ADHD; 5. Reading disorders are frequently co-morbid with ADHD; dyslexia (which is associated with eye movement problems) is linked to a specific visual perceptual deficit in the M pathway, a major recipient of which is the colliculus. Whether or not the SC is indeed hyper-responsive in ADHD as Hypothesis 1 suggests, the SC may well represent an important therapeutic target for drugs. In fact current psychostimulant therapies, which reduce distractibility, may already work at that level (Hypothesis 2), a contention which is supported by: 1. The colliculus and structures immediately afferent to it contain the neurochemical machinery necessary to respond to these drugs; 2. d-Amphetamine depresses visually evoked activity in the rat colliculus in a dose-dependent manner. Fortunately, again, even if psychostimulants do not achieve their therapeutic effects on distractibility in ADHD by acting on the SC, then the development of drugs which dampen stimulus-related activity in the colliculus could still represent an important novel path for drug development to take. Pharmacological manipulations of this structure are able to decrease distractibility. As a consequence, sensory responsiveness in the SC may represent a new model system for use in the development of non-addictive pharmacotherapies for ADHD.     

The genetics of attention deficit hyperactivity disorder

Over the past 15 years, considerable progress has been made in understanding the etiology of childhood Attention Deficit Hyperactivity Disorder (ADHD), largely due to the publication of numerous twin studies which are consistent in suggesting substantial genetic influences (i.e., heritabilities ranging from 60% to 90%), non-shared environmental influences that are small-to-moderate in magnitude (i.e., ranging from 10% to 40%), and little-to-no shared environmental influences. Following from these quantitative genetic findings, numerous molecular genetic studies of association and linkage between ADHD and a variety of candidate genes have been conducted during the past 10 years. The majority of the candidate genes studied underlie various facets of the dopamine, norepinephrine, and serotonin neurotransmitter systems, although the etiological role of candidate genes outside of neurotransmitter systems (e.g., involved in various aspects of brain and nervous system development) have also been examined. In this paper, we review recent findings from candidate gene studies of childhood ADHD and highlight those candidate genes for which associations are most replicable and which thus appear most promising. We conclude with a consideration of some of the emerging themes that will be important in future studies of the genetics of ADHD.     

Spatial orienting and focused attention in attention deficit hyperactivity disorder

Seventeen children with attention deficit disorder (ADHD) and 10 normal controls performed two tasks while event-related potentials were recorded. ADHD subjects took part in two more sessions under methylphenidate (MP) or placebo. In the spatial orienting task, invalidly cued targets elicited a longer reaction time (RT) and a P₃ that was longer in latency and greater in amplitude than did validly cued targets. Performance was similar for both groups, but the early portion of P₃ (300–400 ms) was lower in amplitude for invalidly cued targets in ADHD subjects. MP increased accuracy without affecting RT and shortened P₃ peak latency and increased the amplitude of its early portion. In the focused attention task, accuracy was greater for controls and MP, but there were no RT differenees. Attended stimuli elicited greater amplitude P₁, N₁, and P₃ than did nonattended stimuli, but these measures were unaffected by diagnosis or medication.     

Differentiating major depressive disorder in youths with attention deficit hyperactivity disorder

BACKGROUND: Youths with attention deficit hyperactivity disorders (ADHD) frequently have comorbid major depressive disorders (MDD) sharing overlapping symptoms. Our objective was to examine which depressive symptoms best discriminate MDD among youths with ADHD. METHODS: One-hundred-eleven youths with ADHD (5.2-17.8 years old) and their parents completed interviews with the K-SADS-PL and respective versions of the child or the parent Mood and Feelings Questionnaire (MFQ-C, MFQ-P). Controlling for group differences, logistic regression was used to calculate odds ratios reflecting the accuracy with which various depressive symptoms on the MFQ-C or MFQ-P discriminated MDD. Stepwise logistic regression then identified depressive symptoms that best discriminated the groups with and without MDD, using cross-validated misclassification rate as the criterion. RESULTS: Symptoms that discriminated youths with MDD (n=18) from those without MDD (n=93) were 4 of 6 mood/anhedonia symptoms, all 14 depressed cognition symptoms, and only 3 of 11 physical/vegetative symptoms. Mild irritability, miserable/unhappy moods, and symptoms related to sleep, appetite, energy levels and concentration did not discriminate MDD. A stepwise logistic regression correctly classified 89% of the comorbid MDD subjects, with only age, anhedonia at school, thoughts about killing self, thoughts that bad things would happen, and talking more slowly remaining in the final model. LIMITATIONS: Results of this study may not generalize to community samples because subjects were drawn largely from a university-based outpatient psychiatric clinic. CONCLUSIONS: These findings stress the importance of social withdrawal, anhedonia, depressive cognitions, suicidal thoughts, and psychomotor retardation when trying to identify MDD among ADHD youths.     

The role of sleep disturbances in attention deficit disorder symptoms: a case study

Identified a 10-year-old girl with ADD and a 5-year history of sleep difficulties. Sleep difficulties (delayed sleep phase insomnia) were corrected while performing blind assessments of behavioral symptoms. The intervention (chronotherapy combined with a behavior modification program) resulted in an increase of sleep from 7.2 to 9.2 hours per night. Pre/postintervention behavioral measures indicated significant improvement in positive interactions with peers, increased productivity on a timed arithmetic task, and significantly increased percentage of assigned seatwork completed. Four-month follow-up in the natural school setting indicated improvement in teacher ratings and classroom performance. Despite the persistence of ADD symptomatology, the improvement in sleep apparently contributed to a clinically significant reduction in ADD.     

The age-dependent decline of attention deficit hyperactivity disorder: a meta-analysis of follow-up studies

BACKGROUND: This study examined the persistence of attention deficit hyperactivity disorder (ADHD) into adulthood. METHOD: We analyzed data from published follow-up studies of ADHD. To be included in the analysis, these additional studies had to meet the following criteria: the study included a control group and it was clear from the methods if the diagnosis of ADHD included subjects who did not meet full criteria but showed residual and impairing signs of the disorder. We used a meta-analysis regression model to separately assess the syndromatic and symptomatic persistence of ADHD. RESULTS: When we define only those meeting full criteria for ADHD as having 'persistent ADHD', the rate of persistence is low, approximately 15% at age 25 years. But when we include cases consistent with DSM-IV's definition of ADHD in partial remission, the rate of persistence is much higher, approximately 65%. CONCLUSIONS: Our results show that estimates of ADHD's persistence rely heavily on how one defines persistence. Yet, regardless of definition, our analyses show that evidence for ADHD lessens with age. More work is needed to determine if this reflects true remission of ADHD symptoms or is due to the developmental insensitivity of diagnostic criteria for the disorder.     

Oxidative imbalance in adult attention deficit/hyperactivity disorder

OBJECTIVE: There are few studies evaluating the biochemical basis of adult attention deficit/hyperactivity disorder (A-ADHD). In the present study, we evaluated whether nitric oxide (NO), an oxidant, level and superoxide dismutase (SOD), an antioxidant, activity are associated with A-ADHD or not. METHODS: Twenty A-ADHD patients from Gaziantep University Sahinbey Research Hospital, Psychiatry Clinic, diagnosed according to The Turkish version of Adult ADD/ADHD DSM IV-Based Diagnostic Screening and Rating Scale by two psychiatrists (H.A.S. and S.S.), and twenty-one healthy volunteer controls were included. Blood samples were collected; NO levels and SOD activities were measured. RESULTS: The mean NO levels in patients were significantly higher than those of controls and SOD activity of patients was significantly lower than controls. CONCLUSIONS: Remarkable high levels of oxidant NO, and low SOD activities suggest an oxidative imbalance in A-ADHD. This is the first study evaluating the oxidative metabolism in A-ADHD.     

持续到成人早期的注意缺陷多动障碍的相关因素

目的:探讨儿童注意缺陷多动障碍(ADHD)持续到成人早期的相关因素.方法:对192名符合美国精神障碍诊断与统计手册第4版( DSM-Ⅳ)中ADHD标准的儿童进行随访研究.随访时,根据Conners’成人ADHD诊断会谈定式问卷评定成人早期ADHD情况.将各候选因素在成人ADHD组与成人期功能缓解之间组进行组间比较,对差异有统计学意义的因素进行logistic回归分析.结果:根据DSM-Ⅳ诊断标准,98名(51％)儿童ADHD持续到成人早期.共患ODD [OR=3.14 (1.33 ～7.40),P＜0.01]和接受治疗[ OR =9.56(2.09～43.67),P＜0.01]的患者,ADHD更容易持续到成人早期.结论:本研究提示童年期共患对立违抗性障碍的患者与未共患对立违抗性障碍的患者相比,注意缺陷多动障碍持续到成人早期的比率更高;童年期ADHD需要持续治疗者发展为成人ADHD的风险可能更高.     

Personality assessment of children with attention deficit hyperactivity disorder

The present research was designed to assess several potentially important factors in the personality structure of a sample of children with attention deficit hyperactive disorder (ADHD) as compared to normal control children. Three questionnaires were administered to a group of 28 ADHD boys and to a control group of 83 boys: (1) The Locus of Control Scale for Children; (2) The Revised Children's Manifest Anxiety Scale; and (3) The Persistence Scale for Children. Results showed that the ADHD children had significantly higher external locus of control, were significantly less persistent, and reported an elevated level of “concentration/social worry” (an anxiety subscale). Such findings can help to clarify both the personality structure and the coping styles of the ADHD child.     

Early childhood temperament in pediatric bipolar disorder and attention deficit hyperactivity disorder

Recent theories suggest that children with pediatric bipolar disorder (PBD) may exhibit more difficult temperaments premorbidly, including traits such as behavioral disinhibition and difficulty with emotion regulation. We investigated temperament characteristics retrospectively during infancy and toddlerhood in subjects with PBD (n=25), attention-deficit/hyperactivity disorder (ADHD; n=25), and healthy controls (n=25). Children with PBD were reported to experience increased difficult temperament in both infancy and toddlerhood compared to children with ADHD. Several characteristics of difficult temperament were associated with residual symptoms of mania and depression. Difficult premorbid temperament characteristics may be a specific indicator of a bipolar diathesis, or might signal underlying dysfunction in affective processes that significantly increase risk for a mood disorder.