Does response variability predict distractibility among adults with attention-deficit/hyperactivity disorder?

Increased intraindividual variability in response time (RTSD) has been observed reliably in attention-deficit/hyperactivity disorder (ADHD) and has often been used as a measure of inattention. RTSD is assumed to reflect attentional lapses and distractibility, though evidence for the validity of this connection is lacking. We assessed whether RTSD is an indicator of inattention by comparing RTSD on the stop-signal task (SST) with performance on the delayed oculomotor response (DOR) task, a measure of distractibility. Participants included 30 adults with ADHD and 28 controls. Participants completed the SST and the DOR task, which measured subjects' ability to maintain attention and avoid distraction by inhibiting reflexive saccades toward distractors. On the SST, the ADHD group was slower to inhibit than were controls, indicating poorer inhibitory control in ADHD. The ADHD group also displayed slower reaction times (RTs), greater RTSD, and more omission errors. On the DOR task, the ADHD group displayed more premature saccades (i.e., greater distractibility) than did controls. Greater variability in RT was associated with increased distraction on the DOR task, but only in ADHD participants. Results suggest that RTSD is linked to distractibility among adults with ADHD and support the use of RTSD as a valid measure of inattention in ADHD.     

Does obsessive-compulsive personality disorder belong within the obsessive-compulsive spectrum?

It has been proposed that certain Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Axis I disorders share overlapping clinical features, genetic contributions, and treatment response and fall within an "obsessive-compulsive" spectrum. Obsessive-compulsive personality disorder (OCPD) resembles obsessive-compulsive disorder (OCD) and other spectrum disorders in terms of phenomenology, comorbidity, neurocognition, and treatment response. This article critically examines the nosological profile of OCPD with special reference to OCD and related disorders. By viewing OCPD as a candidate member of the obsessive-compulsive spectrum, we gain a fresh approach to understanding its neurobiology, etiology, and potential treatments.     

Does attention-deficit/hyperactivity disorder have a dimensional latent structure? A taxometric analysis

An understanding of the latent structure of attention-deficit/hyperactivity disorder (ADHD) is essential for developing causal models of this disorder. Although some researchers have presumed that ADHD is dimensional and others have assumed that it is taxonic, there has been relatively little research directly examining the latent structure of ADHD. The authors conducted a set of taxometric analyses using data from the NICHD Study of Early Child Care and Youth Development (ns between 667 and 1,078). The results revealed a dimensional latent structure across a variety of different analyses and sets of indicators for inattention, hyperactivity/impulsivity, and ADHD. Furthermore, analyses of correlations with associated features indicated that dimensional models demonstrated stronger validity coefficients with these criterion measures than dichotomous models. These findings jibe with recent research on the genetic basis of ADHD and with contemporary models of ADHD.     

Does stimulant medication decrease the lower extremity response times of children with and without attention-deficit/hyperactivity disorder?

In 2005 Pedersen and Surburg reported that stimulant medications reduced the lower extremity response times of 16 boys with Attention-Deficit/Hyperactivity Disorder. However, as boys without ADHD and girls with and without ADHD were not studied, one cannot conclude that reported effects represent a medication effect unique to children with ADHD. An alternative hypothesis is presented: that stimulant medications produce an excitatory effect in the central nervous system by increased occupancy of postsynaptic dopamine receptors to reduce the lower extremity response times of children in general. Well-designed controlled clinical trials are needed to evaluate this hypothesis.     

Do boys with attention-deficit/hyperactivity disorder have positive illusory self-concepts?

One hundred ninety-five boys with attention-deficit/hyperactivity disorder (ADHD) were compared with 73 comparison boys (M = 9.83 years, SD = 1.30) on self-perceptions relative to a teacher-rated criterion. Emphasis was placed on ADHD subgroup comparisons according to level of aggression, academic achievement, and depression compared with control boys. Consistent with the authors' prediction, ADHD boys overestimated relative to teacher report, more than did controls, in the scholastic competence, social acceptance, and behavioral conduct domains. Examination of discrepancy scores (child rating - teacher rating) by comorbidity subgroups suggested that aggressive and low-achieving ADHD boys tended to overestimate their competence the most in the domains in which they were the most impaired. Results are discussed in terms of prior literature on "positive illusions" in ADHD children.     

A multi-dimensional model of the origins of attitude certainty: teachers’ attitudes toward attention-deficit/hyperactivity disorder

This research tested and extended a laboratory-derived model of the origins of attitude certainty using a real attitude object: Teaching children with attention-deficit/hyperactivity disorder (ADHD). In Study 1, an experiment manipulated the amount of information, thought, and consistency of information delivered to pre-service teachers ( $n = 224$ ) with no prior experience with ADHD. Structural equation modelling (SEM) of Study 1 did not support the original model, in which relationships between attitude certainty and objective knowledge, thought, and consistency were mediated by perceived knowledge, thought, and ambivalence. Instead, objective amount of information, thought, and consistency interacted in their effect on attitude certainty. Study 2 ( $n = 368$ ) used a survey to test whether experiences with ADHD (personal, direct and indirect) among in-service and pre-service teachers were antecedents of attitude certainty, and to test perceived accessibility as a mediator. SEM supported both these hypotheses. Perceived accessibility and perceived knowledge mediated the relationship between attitude certainty and prior experiences with ADHD, and between attitude certainty and objective knowledge. Together, the results suggest that psychological processes underlying strong attitude certainty differ according to the familiarity and personal relevance of the attitude object, and the context and stage of attitude formation. The results have practical utility for teacher training at pre-service and in-service levels.     

A meta-analytic review of stopping performance in attention-deficit/hyperactivity disorder: deficient inhibitory motor control?

This review discusses whether deficient inhibitory motor control is the core deficit of attention-deficit/hyperactivity disorder (ADHD). Inhibitory motor control is commonly assessed using the stop-signal paradigm. Since the last meta-analysis that was performed, 33 new studies have appeared. The current meta-analysis revealed a significant difference between ADHD patients and matched controls in stop latency (stop-signal reaction time) in both children and adults. Basic reaction time was significantly longer in children with ADHD, but not in adults, and there was a significant interaction between the elongation of the latency to stop and to respond in adults, but not in children. Deficient inhibitory motor control may be less crucial in children than in adults with ADHD.     

Inhibitory deficits and symptoms of attention-deficit hyperactivity disorder: How are they related to effortful control?

Separate studies with clinical and community-based samples have identified an association between symptoms of attention-deficit hyperactivity disorder (ADHD) and inhibitory control deficits and ADHD and weak effortful control. We tested whether differences in effortful control explained the associations between ADHD symptoms and inhibitory control deficits, controlling for conduct problems. In a community sample, parents rated ADHD symptoms, conduct problems, effortful control, surgency and negative affect in 77 4-7-year-olds (47 girls), who performed an inhibitory control task. ADHD symptoms, deficient inhibitory control and low effortful control were correlated. Controlling for conduct problems, path analysis showed the ADHD symptoms – inhibitory control link was mediated statistically by effortful control. This focuses attention on cognitive-energetic factors associated with ADHD-related executive deficits.     

To do or not to do? Prospective memory versus response inhibition in autism spectrum disorder and attention-deficit/hyperactivity disorder

In the present research, event-based prospective memory and response inhibition (RI) abilities were investigated in children with ASD (Study 1), with ADHD (Study 2), and their matched neurotypical controls. Children engaged in a categorisation (ongoing) task and, concurrently, in either an event-based prospective memory (PM) or a Go/No-Go secondary task. Results showed that, as compared to their matched controls, ASD children's performance was more impaired in the PM task than in the Go/No-Go task, while the performance pattern of ADHD children was reversed. In the ongoing task, ASD children were as accurate as, but significantly slower than, controls, independently of conditions. ADHD children did not differ from controls in the presence of a concurrent PM task, while they were less accurate than controls in the presence of the go/no-go task. Overall, the two patterns of findings suggest important differences in the way ASD and ADHD children remember and realise intentions requiring opposite behaviours (acting vs stopping).     

Does power magnify the expression of dispositions?

Conventional wisdom holds that power holders act more in line with their dispositions than do people who lack power. Drawing on principles of construct accessibility, we propose that this is the case only when no alternative constructs are activated. In three experiments, we assessed participants' chronic dispositions and subsequently manipulated participants' degree of power. Participants then either were or were not primed with alternative (i.e., inaccessible or counterdispositional) constructs. When no alternatives were activated, the responses of power holders--perceptions of other people (Experiment 1), preferences for charitable donations (Experiment 2), and strategies in an economic game (Experiment 3)--were more in line with their chronically accessible constructs than were the responses of low-power participants. However, when alternatives had been activated, power holders' responses were no longer more congruent with their dispositions than were the responses of low-power participants. We propose a single mechanism according to which power increases reliance on accessible constructs--that is, constructs that easily come to mind-regardless of whether these constructs are chronically or temporarily accessible.     

Multiple causal pathways in attention-deficit/hyperactivity disorder – Do emerging executive and motivational deviations precede symptom development?

The multiple causal pathways model on the etiology of attention-deficit/hyperactivity disorder (ADHD) is well established. However, developmental implications of the model are not yet sufficiently analyzed. The model implies that critical neural and neuropsychological deviations from normative development precede secondarily developing ADHD symptoms. Cognitive, “cool” inhibitory control (CIC) and reward-related, “hot” functions (RRF) are regarded as neuropsychological basic deficits that indicate independent causal pathways. Both functions involve top-down control networks that undergo major normative developmental changes in the preschool period. We formalized the following assumptions in a path model: (a) CIC and RRF predict change in ADHD symptoms in the preschool period, (b) the reverse is not true, and (c) CIC and RRF independently contribute to this prediction. A community-based sample of 125 (71 boys) preschoolers was assessed at at age 4 and 5 years. At each assessment wave, CIC and RRF were measured by a battery of age-appropriate valid tasks. ADHD symptoms were measured by a clinical parent interview. Evaluation of model fit using manifest maximum likelihood parameter estimation clearly supported the hypothesized path model while controlling for gender of child and maternal education level. Thus, regarding the basic deficits of CIC and RRF, the results add evidence on the developmental implications of the multiple causal pathways model. Our findings point to the potential significance of these early emerging characteristics as indicators of risk and as targets for preventive interventions.     

Obsessive-compulsive disorder with comorbid major depression: what is the role of cognitive factors?

Individuals with obsessive-compulsive disorder (OCD) commonly experience comorbid mood disturbances such as major depressive disorder (MDD). Previous studies that have compared OCD patients with and without MDD have revealed differences in demographic characteristics, clinical severity, and symptom presentation between these two patient groups. Previous studies have not, however, examined whether there are differences with respect to cognitive processes. The present study therefore aimed to address this gap in the literature. Eighty patients with OCD and no unipolar mood disorders were compared with 34 OCD patients with comorbid major depression on measures of OCD symptoms, cognitions, and insight, as well as on measures of depression and functional impairment. Whereas depressed OCD patients evidenced higher scores than non-depressed OCD patients on semi-idiographic measures of OCD symptoms and cognitions, this was not the case for nomothetic measures. Functional impairment and the tendency to misinterpret innocuous intrusive thoughts as significant emerged as unique predictors of depression within the entire sample of OCD patients. Results are discussed in terms of (a) the importance of semi-idiographic assessment of OCD, (b) possible explanations for the relationship between OCD symptoms, depression, and cognitive processes, and (c) the psychological treatment of comorbid OCD and MDD.     

Do traumatic events influence the clinical expression of compulsive hoarding?

Traumatic experiences have been posited as one potential catalyst for the abrupt onset of obsessive-compulsive symptoms including compulsive hoarding. To determine whether traumatic life events (TLEs) might influence the expression of compulsive hoarding in obsessive-compulsive disorder (OCD), interview responses to the Posttraumatic Stress Disorder module of the Structured Clinical Interview for DSM-IV (SCID) were examined in 180 individuals with OCD. Compared to individuals with OCD who did not meet criteria for hoarding, participants classified as hoarders (24% of the sample) were significantly more likely to have reported at least one TLE in their lifetime. Patients who met criteria for hoarding and who had also experienced TLEs had significantly greater hoarding symptom severity than those hoarders not exposed to trauma. This association was found to be robust. That is, the relationship between TLEs and hoarding symptom severity was not better accounted for by age, age of OCD onset, depressive symptoms, general OCD symptomatology, or mood and anxiety comorbidity. Closer examination revealed that the clutter factor of compulsive hoarding (and not difficulty discarding or acquisitioning) was most strongly associated with having experienced a traumatic event.     

How effective are cognitive and behavioral treatments for obsessive-compulsive disorder? A clinical significance analysis

Controlled outcome studies investigating the efficacy of psychological treatments for obsessive-compulsive disorder (OCD) have employed different methods of determining the clinical significance of treatment effects. This makes it difficult to draw conclusions regarding the absolute and relative efficacy of psychological treatments for OCD. To address this issue, standardized Jacobson methodology for defining clinically significant change was applied to recent psychological outcome trials for OCD. The proportion of asymptomatic patients following treatment was also calculated. When recovery is defined by Jacobson methodology, exposure and response prevention (ERP) appears the most effective treatment currently available (50-60% recovered). However, when the asymptomatic criterion is used as the index of outcome, ERP and cognitive therapy have low and equivalent recovery rates (approximately 25%).     

Severity of childhood attention-deficit hyperactivity disorder--a risk factor for personality disorders in adult life?

Some evidence points to an increased rate of cluster B and C personality disorders (PDs) in adult ADHD patients. In order to assess axis II disorders comprehensively we used the diagnostic instrument of the WHO. In sixty adult out-patients with ADHD according to DSM-IV criteria PDs were assessed with the International PD Examination (IPDE) and severity of childhood ADHD with the Wender-Utah-Rating Scale (WURS). We found at least one PD in 25% of cases. Cluster C PDs were most common (36.6%) followed by Cluster B (23.3%) and A (8.3%). Avoidant (21.7%) and borderline (18.3%) were the most frequent single PD entities. ADHD patients with PD suffered from significantly more severe childhood ADHD compared to those without co-occurring PD. Applying the IPDE we confirmed a high number of PDs among adult ADHD patients. Our findings point to a higher vulnerability for the development of PDs in patients with severe childhood ADHD.     

Is the Cogmed program effective for youths with attention deficit/hyperactivity disorder under pharmacological treatment?

The primary objective of this study was to examine the effects of the Cogmed training program on working memory among youths 7 to 13 years old, with attention deficit/hyperactivity disorder (ADHD) type and comorbidity controlled for. A secondary objective was to examine the generalization of effects to ADHD symptoms, nonverbal reasoning, attentional and executive functions, inhibition, reading comprehension, and mathematical reasoning. Participants were under pharmacological treatment for ADHD combined type and a comorbidity. They were randomized into an experimental group that received the Cogmed program and an active control group that received a low-intensity comparison version of the training. They were evaluated at three time points: 6 weeks prior to intervention onset (T1), immediately prior to onset (T2), and 1 week following intervention completion (T3). Results indicate no significant effect attributable to the Cogmed program. The fact that participants were on medication at the time of training and evaluation normalized their performances and limited the detection of effects. Moreover, cognitive training did not lead to a reduction in ADHD symptoms or to an improvement in the other cognitive functions measured or in academic performance. The results of this study do not demonstrate the effectiveness of the Cogmed program for youths with ADHD combined type and a comorbidity when they receive the training while under pharmacological treatment.     

Adaptation to an autoimmune disorder: Does mental flexibility impact illness-related self-regulation?

Objective: To examine whether mental flexibility moderates the relationship between illness representations of control and coping behaviour in individuals suffering from rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

Design: Recently, diagnosed RA (N = 80) and SLE (N = 75) patients completed questionnaires about illness representations of personal and treatment control and four coping behaviours: instrumental coping, adherence to medical advice, palliative coping and wishful thinking. Mental flexibility was assessed with the Trail Making Test Part B (TMT-B), while visuomotor processing speed, as a confounder, was assessed with the Trail Making Test Part A (TMT-A). Moderated mediation models were tested within a bootstrapped multiple regression framework.

Results: TMT-A scores had no statistically significant moderation effects on the relation between representations and coping behaviour. Conversely, in those participants with SLE, TMT-B scores moderated the relation of personal control to wishful thinking and palliative coping, as well as the relation of treatment control to both wishful thinking and palliative coping. All significant effects were restricted to the SLE group.

Conclusion: Interactions between neurocognitive factors and the process of illness adaptation may emerge early during the course of SLE. The present findings highlight the role of cognitive functioning as an integral part of the illness-related self-regulation mechanism.