Symptoms Of Impulsivity Research Articles

Cortical Development in Typically Developing Children With Symptoms of Hyperactivity and Impulsivity: Support for a Dimensional View of Attention Deficit Hyperactivity Disorder

Cortical Development in Typically Developing Children With Symptoms of Hyperactivity and Impulsivity: Support for a Dimensional View of Attention Deficit Hyperactivity Disorder

Orbitofrontal reward sensitivity and impulsivity in adult attention deficit hyperactivity disorder

Impulsivity symptoms of adult attention deficit hyperactivity disorder (ADHD) such as increased risk taking have been linked with impaired reward processing. Previous studies have focused on reward anticipation or on rewarded executive functioning tasks and have described a striatal hyporesponsiveness and orbitofrontal alterations in adult and adolescent ADHD. Passive reward delivery and its link to behavioral impulsivity are less well understood. To study this crucial aspect of reward processing we used functional magnetic resonance imaging (fMRI) combined with electrodermal assessment in male and female adult ADHD patients (N=28) and matched healthy control participants (N=28) during delivery of monetary and non-monetary rewards. Further, two behavioral tasks assessed risky decision making (game of dice task) and delay discounting. Results indicated that both groups activated ventral and dorsal striatum and the medial orbitofrontal cortex (mOFC) in response to high-incentive (i.e. monetary) rewards. A similar, albeit less strong activation pattern was found for low-incentive (i.e. non-monetary) rewards. Group differences emerged when comparing high and low incentive rewards directly: activation in the mOFC coded for the motivational change in reward delivery in healthy controls, but not ADHD patients. Additionally, this dysfunctional mOFC activity in patients correlated with risky decision making and delay discounting and was paralleled by physiological arousal. Together, these results suggest that the mOFC codes reward value and type in healthy individuals whereas this function is deficient in ADHD. The brain-behavior correlations suggest that this deficit might be related to behavioral impulsivity. Reward value processing difficulties in ADHD should be considered when assessing reward anticipation and emotional learning in research and applied settings.

Aberrant reward processing in Parkinson's disease is associated with dopamine cell loss

Dopamine has been implicated in reward-related impulsivity, but the exact relationship between dopamine, reward and impulsivity in humans remains unknown. We address this question in Parkinson's disease (PD), which is characterized by severe dopamine depletion. PD is associated primarily with motor and cognitive inflexibility, but can also be accompanied by reward-related impulsivity. This paradoxical symptom of PD has often been attributed to dopaminergic overstimulation by antiparkinson medication, which is necessary to relieve the motor and cognitive inflexibility. However, factors other than medication may also contribute to aberrant impact of reward. Here we assess whether cognitive inflexibility and aberrant reward impact in PD are two sides of the same coin, namely dopamine cell loss. To measure dopamine cell loss, we employed (123)I-FP-CIT Single Photon Emission Computed Tomography (SPECT) in 32 PD patients (10 never-medicated patients and 22 patients after withdrawal of all medication for >12h) and related the values to behavior on a rewarded task-switching paradigm. Dopamine cell loss was associated not only with cognitive inflexibility (under low reward), but also with aberrant impact of reward. These effects could not be attributed to medication use. Relative to controls (n=26), aberrant reward processing in PD was particularly expressed as reduced capacity to maintain (i.e., repeat) the current task-set under high reward. Our findings demonstrate that factors intrinsically related to PD may underlie the paradoxical symptoms of inflexibility and reward-related impulsivity in PD. The present results concur with observations that low baseline dopamine states predispose to drug and other addictions.

Editorial: Seeking a new characterisation of learning disorders

Editorial: Seeking a new characterisation of learning disorders

Reliability and component structure of the modified Daily Symptom Report (DSR-20)

The purpose of the present study was to modify Freeman et al.'s (1996) Daily Symptom Report (DSR) for premenstrual syndrome (PMS) by adding items depicting aggressive and impulsive symptoms, to explore the component structure of this revised measure (DSR-20) in a sample of PMS sufferers, and to compare their scores with those from controls during the follicular and luteal cycle phases. The DSR-20 was administered to 140 PMS sufferers who were seeking treatment for PMS and 54 controls who considered themselves to be free from premenstrual complaints daily for three menstrual cycles. Cronbach's α was 0.95 for the luteal DSR-20 scores of the PMS sufferers, indicating very high internal consistency of the 20 items. Exploratory Principal Components Analysis (PCA) of the luteal ratings of the PMS sufferers identified two components with high internal consistency (>0.90), describing psychological and physical premenstrual symptoms. PMS sufferers scored significantly higher than the controls on each of these components during the luteal, but not follicular, phase. The DSR-20 total scale score is an internally consistent global measure of the intensity of PMS. The division of PMS symptoms into psychological and physical components, both of which significantly differentiated PMS sufferers from controls during the luteal phase, sheds further light on the description of PMS and provides a clinically relevant and practical means by which to summarise and interpret daily symptom ratings, necessary for the identification and investigation of the syndrome.

ADHD and Female Specific Concerns

ADHD was once thought of as a predominantly male disorder. While this may be true for ADHD in childhood, extant research suggests that the number of women with ADHD may be nearly equal to that of men with the disorder (Faraone et al., 2000). There is accumulating research which clearly indicates subtle but important sex differences exist in the symptom profile, neuropathology and clinical course of ADHD. Compared to males with ADHD, females with ADHD are more prone to have difficulties with inattentive symptoms than hyperactive and impulsive symptoms, and females often receive a diagnosis of ADHD significantly later than do males (Gaub & Carlson, 1997; Gershon, 2002a, 2002b). Emerging evidence suggests differences exist in the neuropathology of ADHD, and there are hormonal factors which may play an important role in understanding ADHD in females. Although research demonstrates females with ADHD differ from males in important ways, little research exists that evaluates differences in treatment response. Given the subtle but important differences in presentation and developmental course of ADHD, it is essential that both clinical practice and research be informed by awareness of these differences in order to better identify and promote improved quality of care to girls and women with ADHD.

Animal models to guide clinical drug development in ADHD: lost in translation?

We review strategies for developing animal models for examining and selecting compounds with potential therapeutic benefit in attention-deficit hyperactivity disorder (ADHD). ADHD is a behavioural disorder of unknown aetiology and pathophysiology. Current understanding suggests that genetic factors play an important role in the aetiology of ADHD. The involvement of dopaminergic and noradrenergic systems in the pathophysiology of ADHD is probable. We review the clinical features of ADHD including inattention, hyperactivity and impulsivity and how these are operationalized for laboratory study. Measures of temporal discounting (but not premature responding) appear to predict known drug effects well (treatment validity). Open-field measures of overactivity commonly used do not have treatment validity in human populations. A number of animal models have been proposed that simulate the symptoms of ADHD. The most commonly used are the spontaneously hypertensive rat (SHR) and the 6-hydroxydopamine-lesioned (6-OHDA) animals. To date, however, the SHR lacks treatment validity, and the effects of drugs on symptoms of impulsivity and inattention have not been studied extensively in 6-OHDA-lesioned animals. At the present stage of development, there are no in vivo models of proven effectiveness for examining and selecting compounds with potential therapeutic benefit in ADHD. However, temporal discounting is an emerging theme in theories of ADHD, and there is good evidence of increased value of delayed reward following treatment with stimulant drugs. Therefore, operant behaviour paradigms that measure the effects of drugs in situations of delayed reinforcement, whether in normal rats or selected models, show promise for the future.

Childhood attention‐deficit hyperactivity disorder as an extreme of a continuous trait: a quantitative genetic study of 8,500 twin pairs

Although the clinical utility of categorically defined attention-deficit hyperactivity disorder (ADHD) is well established, there is also strong evidence supporting the notion of ADHD as an extreme of a continuous trait. Nevertheless, the question of whether the etiology is the same for different levels of DSM-IV ADHD symptoms remains to be investigated. The aim of this study was to assess genetic links between the extreme and the subthreshold range of ADHD symptoms. Parents of all Swedish 9- and 12-year-old twins born between 1992 and 2000 were interviewed for DSM-IV ADHD symptoms and associated conditions. Two validated cutoff values were used for screening and assigning research diagnoses. Response rate was 80%. Twin methods were applied to investigate the extent to which ADHD is etiologically distinct from subthreshold variations in ADHD symptoms. Extremes analyses indicated a strong genetic link between the extreme and the subthreshold variation, with almost identical group heritability estimates around .60 for the diagnostic (prevalence 1.78%) and screening (prevalence 9.75%) criteria of ADHD. A strong genetic link between the extreme and the subthreshold variation of DSM-IV based assessments of ADHD symptoms was found. The data suggest that ADHD is best viewed as the quantitative extreme of genetic and environmental factors operating dimensionally throughout the distribution of ADHD symptoms, indicating that the same etiologic factors are involved in the full range of symptoms of inattention, hyperactivity and impulsivity.

ADHD and offenders

Objectives. To present the needs and psychological treatment options for offenders with ADHD. Methods. Key papers are discussed in relation to this topic. Results. Research suggests there is a disproportionately high number of individuals with ADHD involved with the Criminal Justice System. UK studies among offenders have indicated around 45% of youths and 24% of male adults screen positive for a childhood history of ADHD, 14% of whom have persisting symptoms in adulthood. Those with persisting symptoms have a significantly younger onset of offending and higher rate of recidivism. ADHD was the most powerful predictor of violent offending, even above substance misuse. They accounted for 8-fold more institutional aggressive behavioural disturbances (critical incidents) than other non-ADHD prisoners. Critical incidents have also been associated with personality disordered patients screening positive for ADHD and detained under the Mental Health Act. It is the impulsive symptoms and mood instability associated with ADHD that most likely increase the risk of critical incidents within institutional settings. Conclusions. There are international guidelines available for the treatment of ADHD; however, serious offenders with ADHD will require more complex and comprehensive interventions than their non-offending peers. In particular psychological interventions need to be provided that contain a prosocial competence component. One such programme, the R&R2 for ADHD Youths and Adults, has demonstrated improvement in ADHD symptoms, anxiety, depression, antisocial behaviour and social functioning at three month follow-up with medium to large effect sizes.

Neurofeedback in ADHD: a single-blind randomized controlled trial

Neurofeedback treatment has been demonstrated to reduce inattention, impulsivity and hyperactivity in children with attention deficit/hyperactivity disorder (ADHD). However, previous studies did not adequately control confounding variables or did not employ a randomized reinforcer-controlled design. This study addresses those methodological shortcomings by comparing the effects of the following two matched biofeedback training variants on the primary symptoms of ADHD: EEG neurofeedback (NF) aiming at theta/beta ratio reduction and EMG biofeedback (BF) aiming at forehead muscle relaxation. Thirty-five children with ADHD (26 boys, 9 girls; 6-14years old) were randomly assigned to either the therapy group (NF; n=18) or the control group (BF; n=17). Treatment for both groups consisted of 30 sessions. Pre- and post-treatment assessment consisted of psychophysiological measures, behavioural rating scales completed by parents and teachers, as well as psychometric measures. Training effectively reduced theta/beta ratios and EMG levels in the NF and BF groups, respectively. Parents reported significant reductions in primary ADHD symptoms, and inattention improvements in the NF group were higher compared to the control intervention (BF, d (corr)=-.94). NF training also improved attention and reaction times on the psychometric measures. The results indicate that NF effectively reduced inattention symptoms on parent rating scales and reaction time in neuropsychological tests. However, regarding hyperactivity and impulsivity symptoms, the results imply that non-specific factors, such as behavioural contingencies, self-efficacy, structured learning environment and feed-forward processes, may also contribute to the positive behavioural effects induced by neurofeedback training.

Lifespan attention deficit/hyperactivity disorder and borderline personality disorder symptoms in female patients: A latent class approach

Attention-deficit/hyperactivity disorder (ADHD) and borderline personality disorder (BPD) are frequently comorbid. To contribute to a better understanding of the associations regularly found between ADHD and BPD, on the one hand, and the developmental pathways for these disorders, on the other hand, latent class analyses (LCA) were undertaken to identify classes differing in profiles of childhood symptoms of ADHD and adult symptoms of ADHD and BPD. Diagnostic interviews with 103 female outpatients meeting the criteria for ADHD and/or BPD were used to assess current DSM-IV symptoms; childhood symptoms of ADHD were assessed in parent interviews. The latent classes were examined in relation to the DSM-IV conceptualizations of ADHD and BPD. And relations between childhood and adult classes were examined to hypothesize about developmental trajectories. LCA revealed an optimal solution with four distinct symptom profiles: only ADHD symptoms; BPD symptoms and only ADHD symptoms of hyperactivity; BPD symptoms and ADHD symptoms of inattention and hyperactivity; BPD symptoms and ADHD symptoms of inattention, hyperactivity and impulsivity. All patients with BPD had some ADHD symptoms in both adulthood and childhood. Hyperactivity was least discriminative of adult classes. Adult hyperactivity was not always preceded by childhood hyperactivity; some cases of comorbid ADHD and BPD symptoms were not preceded by significant childhood ADHD symptoms; and some cases of predominantly BPD symptoms could be traced back to combined symptoms of ADHD in childhood. The results underline the importance of taking ADHD diagnoses into account with BPD. ADHD classification subtypes may not be permanent over time, and different developmental pathways to adult ADHD and BPD should therefore be investigated.

Effects of acute and chronic methylphenidate on delay discounting

Methylphenidate (MPH) is one of the most common therapeutics used for the treatment of attention-deficit/hyperactivity disorder (ADHD), which consists of symptoms of inattention, and/or impulsivity and hyperactivity. Acute administration of MPH has been found to decrease impulsive choice in both humans and nonhuman animals, however, little is known about potential long-term changes in impulsive choice due to chronic administration of MPH. In the present experiment, effects of acute and chronic MPH (1.0–10.0mg/kg) were assessed on impulsive choice in the adult male Spontaneously Hypertensive Rat (SHR) to determine the extent of behavioral changes after chronic MPH exposure. Subjects chose between an immediate single food pellet and three food pellets delivered after a delay that increased within session (0 to 16s). At relatively higher doses during acute and chronic administration, choice maintained by the larger reinforcer was disrupted when there was no delay to either outcome, suggesting that MPH may be affecting stimulus control under the current delay-discounting task. When this disruption was not observed, however, MPH effects were selective in that only one intermediate dose (3.0mg/kg) decreased mean impulsive choice at one delay (8s) following acute administration. The same effect was observed following chronic MPH administration except that the dose was higher (5.6mg/kg) and the delay was shorter (4s). Chronic administration of MPH did not show any negative indicators (e.g., an increase in impulsive choice) when administration was discontinued.

Brain functional domains inform therapeutic interventions in attention-deficit/hyperactivity disorder and pediatric bipolar disorder

A deeper understanding of how the relationships between impulsivity, reward systems and executive function deficits may be similar or different in attention-deficit/hyperactivity disorder (ADHD) and pediatric bipolar disorder (PBD) is fundamental for better defining phenotypy in these two developmental illnesses, and moving towards improved treatment and intervention. We focus our article on recent neurocognitive and neuroimaging data examining the behavioral and neural aspects of poor behavior regulation, response inhibition and reward systems in ADHD and PBD. In light of recent research evidence, we propose that the common behavioral manifestations of impulsivity in ADHD and PBD may indeed originate from different neural mechanisms mediated by altered reward systems. In order to define and differentiate these mechanisms, unlike previous approaches, our theoretical model examines the interface of the dorsal frontostriatal circuit, involved in behavior regulation, and the ventral frontostriatal circuit, which is involved in reward-related and affect processes. Preliminary evidence suggests that the neural systems involved in impulsivity, reward systems and executive function engage differently in the two illnesses. In PBD, ‘emotional impulsivity’ is predominantly ‘bottom-up’ and emotionally/motivationally driven, and stems from ventral frontostriatal circuitry dysfunction. By contrast, in ADHD ‘cognitive impulsivity’ is predominantly ‘top-down’ and more ‘cognitively driven’, and stems from dorsal frontostriatal dysfunction. We discuss this evidence in view of clinically relevant questions and implications for illness-based intervention. We conclude that the reward-related mechanisms underlying the interactions between executive function, behavior regulation and impulsivity in PBD and ADHD may be differentially compromised, and in accordance differently shape the clinical symptoms of impulsivity and goal-directed behavior.

Neuroimaging in the diagnosis of ADHD: where we are and where we are going

Attention-deficit/hyperactivity disorder (ADHD) is a highly prevalent childhood psychiatric disorder. ADHD manifests with symptoms of inattention, hyperactivity and/or impulsivity that pervade in the familiar, academic and social spheres. There are serious concerns about the widespread misdiagnosis of ADHD that, together with the fast growing use of neuroimaging techniques in ADHD research, have prompted an inquiry into the feasibility of an imaging test for the diagnosis of ADHD that could aid in clinical practice. This article consists of a brief review of the main neuroimaging research findings in ADHD and its contributions to the current understanding of the ADHD neurobiology, highlighting aspects that could eventually be utilized as a basis for diagnostic tests. The paper then outlines and applies a multiphase approach for developing diagnostic imaging tests in psychiatry to evaluate their prospects for the diagnosis of ADHD as well as evaluating a recently proposed diagnostic imaging test. It appears obvious that a diagnostic imaging test for ADHD should be based on the state-of-the-art neuroimaging techniques now available from ADHD neurobiology research. However, the deriviation of an imaging diagnostic tool from neuroimaging research is not as straightforward as it may seem, with several prerequisites that must be met in advance. The author suggests that a consistent decreased volume of right caudate nucleus in ADHD samples could provide a good basis for any future diagnostic imaging test.

Relations among academic enablers and academic achievement in children with and without high levels of parent‐rated symptoms of inattention, impulsivity, and hyperactivity

AbstractThis study examined the relationships among academic enablers (i.e., engagement, interpersonal skills, motivation, study skills) and academic achievement in children with and without high levels of parent‐rated symptoms of inattention, impulsivity, and hyperactivity (Symptoms of IIH Group). The study included 69 participants (29 [42%] in the IIH Group and 40 [58%] in the Comparison Group), with 33 boys and 36 girls in the third through fifth grades. The researchers found significant differences on the measure of academic enablers, including engagement, interpersonal skills, motivation, and study skills, in which participants in the Comparison Group received higher scores. In addition, several academic enablers mediated the relationship between symptoms of inattention, impulsivity, and hyperactivity and the academic outcomes of reading and teachers' ratings of total academic skills. © 2011 Wiley Periodicals, Inc.

Effects of smoking abstinence on impulsive behavior among smokers high and low in ADHD-like symptoms

Impulsivity, a multifaceted construct that includes inhibitory control and heightened preference for immediate reward, is central to models of drug use and abuse. Within a self-medication framework, abstinence from smoking may lead to an increase in impulsive behavior and the likelihood of relapse, particularly among persons with disorders (e.g., attention-deficit/hyperactivity disorder, ADHD) and personality traits (e.g., impulsivity) linked to impulsive behavior. This study aimed to examine the effects of smoking abstinence on multiple measures of impulsivity among a non-clinical sample of adult smokers selected for high and low levels of ADHD symptoms. In a within-subjects design, participants selected for high or low levels of self-reported ADHD symptoms (N = 56) completed sessions following overnight abstinence and when smoking as usual (order counterbalanced). Measures of impulsive behavior included response inhibition (i.e., stop signal task), interference control (i.e., attentional modification of prepulse inhibition (PPI) of startle), and impulsive choice (i.e., hypothetical delay discounting). As hypothesized, abstinence decreased response inhibition and PPI. Although ADHD symptoms moderated abstinence effects on impulsive choice and response inhibition, the pattern was opposite to our predictions: the low-ADHD group responded more impulsively when abstinent, whereas the high-ADHD group was relatively unaffected by abstinence. These findings highlight the importance of utilizing multiple laboratory measures to examine a multifactorial construct such as impulsive behavior and raise questions about how best to assess symptoms of ADHD and impulsivity among non-abstinent smokers.

Sustained Attention and Behavioral Characteristics Associated with ADHD in Adults

The goal of the current study was to investigate whether two cognitive functions (i.e., sustained attention and response inhibition) were related to a general model of personality traits and behavioral characteristics associated with attention-deficit hyperactivity disorder (ADHD). To examine these relations, the Conjunctive Continuous Performance Test was used to measure the two cognitive functions, the Mini-Marker was used to measure the Big Five domains of personality, and the Wender Utah Rating Scale (WURS) was used to index ADHD symptoms. Correlations and multiple regression analyses showed that difficulties in sustained attention were associated with the WURS behavioral symptoms of inattention, oppositional/defiant behavior, impulsivity, and Big Five low conscientiousness, but were not associated with emotional problems such as neuroticism or low agreeableness (Big Five). Difficulties in response inhibition were marginally correlated with behavioral symptoms of inattention and low conscientiousness. Surprisingly, response inhibition was also highly correlated with sustained attention. In addition, neuroticism independently was highly associated with the WURS emotional and oppositional/defiant behavior symptoms. The findings suggest that deficient sustained attention relates specifically to the main ADHD behaviors but not to the emotional problems typically associated with the disorder.

Dose Response Effects of Lisdexamfetamine Dimesylate Treatment in Adults With ADHD

Objective: To explore dose–response effects of lisdexamfetamine dimesylate (LDX) treatment for ADHD. Method: This was a 4-week, randomized, double-blinded, placebo-controlled, parallel-group, forced-dose titration study in adult participants, aged 18 to 55 years, meeting Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.) criteria for ADHD. Results: Nearly all participants assigned to an LDX dose achieved their assigned dose with the exception of about 4% of participants assigned to the 50 mg or 14% assigned to the 70 mg doses. Higher doses of LDX led to greater improvements in ADHD-rating scale scores, independent of prior pharmacotherapy. This was evident for both inattentive and hyperactive–impulsive symptoms. The authors found some evidence for an interaction between LDX dose and baseline severity of ADHD symptoms. Conclusion: For LDX doses between 30 and 70 mg/d, the dose–response efficacy effect for LDX is not affected by prior pharmacotherapy, but patients with a greater severity of illness may benefit more from higher doses, especially for hyperactive–impulsive symptoms. The results do not provide information about doses above 70 mg/d, which is the maximum approved dose of LDX and the highest dose studied in ADHD clinical trials.

Symptomatic overlap between attention-deficit/hyperactivity disorder and borderline personality disorder in women: the role of temperament and character traits

ObjectiveThere is substantial symptomatic overlap between attention-deficit/hyperactivity disorder (ADHD) and borderline personality disorder (BPD) in adults, but the nature of the relationship between these disorders needs further clarification. The role of temperament and character traits in the differentiation of classes of patients with similar ADHD and BPD symptom profiles was examined and possible pathways between early temperament and future ADHD and/or BPD were hypothesized. MethodsStructured diagnostic interviews were conducted in 103 female patients to assess current Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition symptoms of ADHD and BPD, and parent interviews were used to assess ADHD symptoms in childhood. Classes of subjects with homogeneous symptom profiles were identified using latent class analysis. Temperament and character traits were assessed using the Temperament and Character Inventory of Cloninger et al; scores were then compared across the latent classes. ResultsLatent class analysis revealed 4 mutually exclusive classes of patients: 1 with only ADHD symptoms; 1 with BPD symptoms and ADHD symptoms of hyperactivity; 1 with BPD symptoms and ADHD symptoms of inattention, hyperactivity, and impulsivity; and 1 with BPD symptoms and ADHD symptoms of inattention and hyperactivity. High Novelty Seeking was found in all classes except for the class with symptoms of BPD and only the hyperactivity aspect of ADHD. The highest Novelty Seeking temperament scores were found in that class of patients with both symptoms of BPD and symptoms in all areas of ADHD. High Harm Avoidance, low Cooperativeness, and low Self-directedness were specifically related to classes containing BPD symptoms. ConclusionsClasses of ADHD and BPD symptoms are associated with specific temperament and character configurations. Novelty Seeking was associated with the inattention symptoms of ADHD. An outspoken Novelty Seeking temperament suggests vulnerability for the development of ADHD and co-occurring BPD. Contrary to patients with combined ADHD and BPD symptoms, patients with only symptoms of ADHD showed normal character development and thus an absence of a personality disorder. Assessment of temperament and character traits can improve our understanding of the complex relationship between ADHD and BPD.

Obsessive-Compulsive Spectrum Disorder Symptoms in College Students

Objective: This study investigated the occurrence of obsessive-compulsive spectrum disorders (OCSDs) and associated symptomology in college students. Participants: Participants included 358 undergraduate students. Results: Results suggest that clinically significant levels of OCSD symptoms are relatively common. Additionally, OCSD symptoms co-occurred with each other and anxiety symptoms in general, yet not significantly with impulsivity symptoms. Conclusions: Given their prevalence in college students and potentially debilitating nature, it is important to increase awareness of OCSDs so that health professionals can better identify and treat symptoms of these disorders.