Non-medicated Attention Deficit/hyperactivity Disorder Research Articles

The influence of methylphenidate on auditory brainstem response patients with attention deficit hyperactivity disorder; an exploratory study.

Attention-deficit hyperactivity disorder (ADHD), characterized by periods of inattention, overactivity, and impulsiveness, is the most prevalent neurodevelopmental disorder among children. Auditory Brainstem Response (ABR) is a technique in which clickshaped sounds elicit potentials that are recorded from electrodes placed on a patient's skull. Extant research indicates that ABR is frequently affected in neurodevelopmental disorders such as ADHD. Methylphenidate (MPH), a psychostimulant, is often prescribed to children with ADHD as a first-line pharmacological treatment. The aim of this study was to explore the effects of Methylphenidate treatment on previously observed amplitude alterations in the ABR of patients with ADHD. We recruited 32 drug-naïve children and adolescents (19 males and 13 females; mean age 11 years) diagnosed with ADHD and 35 health controls (15 males and 20 females; mean age 12 years). The ADHD group was treated with Methylphenidate, and ABR was recorded before treatment and at a steady state of medical treatment. Medicated ADHD patients exhibited increased activity in the right side ABR in Wave VI. A significant increase in activity was found in a part of the ABR thought to correspond to the thalamic area in medicated ADHD patients compared to the same area of non-medicated ADHD patients. The results add to the growing body of research suggesting that specific ABR peaks correlate to certain psychiatric symptoms.

The ball search field task in the evaluation of methylphenidate treatment of children with attention deficit / hyperactivity disorder

Assessing behavioral change in psychiatric contexts requires retesting patients where, however, ecologically relevant tasks are rarely used. We employed the Ball Search Field Task (BSFT) to evaluate the performance of attention deficit/hyperactivity disorder (ADHD) outpatients before and after administration of methylphenidate (MPH) and compared their performance with that of non-medicated ADHD outpatients and age-matched controls. The outpatient groups showed poorer performance at initial testing, improved performance at re-test although not to the level of the controls, and no clear effect of MPH treatment. The BSFT is thus sufficiently motivating and discriminating for the behavioral evaluation of treatments in psychiatric contexts.

Visual Perceptual Skills in Attention-deficit/Hyperactivity Disorder Children: The Mediating Role of Comorbidities.

Attention-deficit/hyperactivity disorder (ADHD) has been commonly associated with alterations in visual perception. However, the individual behavior of visual perceptual skills and its relationship with different comorbidities remain unknown. The purpose of this study was to examine whether visual perceptual skills are impaired in children with ADHD, as well as to test the possible mediating role of comorbidities. Thirty-five nonmedicated ADHD (20 pure and 15 with comorbidities) and 35 age-matched controls completed the performance-based Test of Visual Perceptual Skills. The analysis between total ADHD and controls favored the alternative hypothesis (greater values for children with ADHD) for visual memory, spatial relationships, sequential memory, and all the composite measures (Bayes factor [BF] range, 4.26 to 366.85). The analysis between pure ADHD and controls showed that data are more likely under the alternative hypothesis for spatial relationships, sequential memory, overall, basic, and sequencing (BF range, 3.82 to 21.71), whereas the comparison between ADHD with comorbidities and controls additionally favored the alternative hypothesis for visual discrimination (BF = 5.37). Lastly, data from the comparison between pure ADHD and ADHD with comorbidities were insensitive for favoring the null or alternative hypotheses in any subtest or composite scaled score (BF range, 0.33 to 0.66). Our results suggest that some specific patterns of visual perception are altered in ADHD, especially for the total ADHD group. The current findings also evidence that comorbidities play an important role in the association between ADHD and visual perceptual skills. Future studies should address the mediating role of each specific type of comorbidity.

Electroencephalography Functional Networks Reveal Global Effects of Methylphenidate in Youth with Attention Deficit/Hyperactivity Disorder.

Methylphenidate (MPH) is the leading drug for treatment of attention deficit/hyperactivity disorder (ADHD), yet its underlying neuronal mechanisms are still unclear. Here, we use a dynamical brain networks approach to explore the effects of cognitive effort and MPH on ADHD subjects. Electroencephalography data were recorded from 19 ADHD subjects and 18 controls during a Go/No-Go Task. ADHD subjects completed the task twice a day over 2 days. The second session was administered post-ingestion of placebo/MPH (alternately). Controls performed two tasks in 1 day. The data were divided into 300 ms windows from -300 pre-stimulus until 1200 ms post-stimulus. Brain networks were constructed per subject and window, from which network metrics were extracted and compared across the experimental conditions. We identified an immediate shift of global connectivity and of network segregation after the stimulus for both groups, followed by a gradual return to baseline. Decreased global connectivity was found to be 400-700 ms post-stimulus in ADHD compared with controls, and it was normalized post-MPH. An increase of the networks' segregation occurred post-placebo at 100-400 and 400-700 ms post-stimulus, yet it was inhibited post-MPH. These global alterations resulted mainly from changes in task-relevant frontal and parietal regions. The networks of medicated ADHD subjects and controls exhibited a more significant and lasting change, relative to baseline, compared with those of nonmedicated ADHD. These results suggest impaired network flexibility in ADHD, corrected by MPH.

Attention-deficit/hyperactivity disorder children exhibit an impaired accommodative response.

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common paediatric neurobehavioural disorders causing multiple functional impairments in children. Based on the relationship between the neural system that controls attention and ocular dynamics, the present study compares the magnitude and variability of accommodation between a group of non-medicated ADHD children and an age-matched control group. The magnitude and variability of the accommodative response were objectively measured in 36 children using the WAM-5500 autorefractometer for 90 consecutive seconds at three static viewing distances (500, 40, and 20cm). Participants were divided into ADHD (n = 18) or control (n = 18) groups based on clinically validated criteria. Children with ADHD exhibited higher lags of accommodation (p = 0.024), increasing at closer viewing distances, in comparison to the control group. Marginal statistical differences were found for the variability of accommodation (p = 0.066), with the ADHD group showing a trend towards higher variability. Our analysis showed that the magnitude and variability of accommodation did not vary over time between groups (p > 0.05). Our data suggest that children with ADHD have a less accurate accommodative response. These results provide a new ocular index that could help to clarify the relationship between accommodative response and attentional deficits, which could have a direct impact on the academic, cognitive, and visual performance of ADHD children.

Saliva and Oral Health in Attention Deficit Hyperactivity Disorder (ADHD)

Purpose: It’s estimated that 9% of children in the United States have been diagnosed with attention deficit hyperactivity disorder (ADHD) and many take medications to control their disease. Since the results of clinical studies on the oral health of ADHD patients have been inconclusive, we compared salivary function and oral health in medicated and non-medicated ADHD and healthy subjects. Methods: Fifty (50) children (6-17 y; female/ male: 1:1.8) were recruited. Group 1 subjects were diagnosed with ADHD and medicated (n=16), Group 2 had ADHD and not medicated (n=17), and Group 3 were healthy (n=17). Whole saliva was collected and flow rate, pH, buffering capacity, and level of secretory Immunoglobulin A (sIgA), cortisol and total protein determined. Nonparametric statistics were used. Results: ADHD children taking medication did not show any significant change in salivary flow rate, pH, buffering capacity, and level of salivary total protein, sIgA, and cortisol compared to non-medicated ADHD and healthy subjects (P>0.5). Streptococcus mutans (S.mutans) has been correlated with caries risk, but in these subjects there was no significant difference between groups. Conclusion: Our results suggest that medicated and non-medicated ADHD patients (6-17 y) have no additional risk for oral diseases or salivary dysfunction compared to healthy controls.

Reduced striatal brain volumes in non-medicated adult ADHD patients with comorbid cocaine dependence

BackgroundAdult attention deficit/hyperactivity disorder (ADHD) is highly comorbid with other psychiatric disorders, including substance use disorders (SUD). Patients with ADHD and SUD comorbidity respond less well to pharmacological treatment (e.g., methylphenidate), have more severe ADHD symptoms, and are generally more impulsive than ADHD patients without SUD. However, little is known about structural brain abnormalities that may differentiate ADHD patients with and without comorbid SUD. MethodsWe compared regional grey matter volumes of 10 non-medicated male ADHD patients with comorbid cocaine dependence, 14 non-medicated male ADHD patients without cocaine dependence and 15 healthy control participants matched for age and premorbid intellectual functioning, using voxel-based morphometry (VBM) using both a whole-brain analysis and a priori ROI analysis based on the existing ADHD VBM literature. ResultsIn a whole brain analysis, ADHD patients with and without cocaine dependence showed smaller volumes in the right putamen and cerebellum compared to healthy controls. In addition, ADHD patients without cocaine dependence showed larger volumes in the midbrain and in the precentral gyrus compared to healthy control participants and larger volumes in the occipital cortex compared to ADHD patients with comorbid cocaine dependence. A direct comparison using the a priori defined ROI approach showed that ADHD patients with cocaine dependence had smaller putamen volumes than ADHD patients without cocaine dependence. ConclusionsADHD patients with cocaine dependence show more profound grey matter volume reductions in the striatum compared to ADHD patients without cocaine dependence. Possible implications for treatment are discussed.

Stimulant medications for attention-deficit/hyperactivity disorder (ADHD) improve memory of emotional stimuli in ADHD-diagnosed college students

ObjectiveStimulant medications do not improve the academic achievement of ADHD diagnosed undergraduates. One reason may be that stimulant-induced sympathetic arousal might impair memory. Participants and methodsTo test this hypothesis, we conducted a study between September 2011 and March 2012, to compare medicated (n=12) and non-medicated (n=11) ADHD diagnosed undergraduates, with non-ADHD students (n=12). All participants were presented with an audiovisual narrative that included an emotional segment, and answered questions about the story one week later. ResultsAll groups remembered the emotional segment significantly better than the neutral segments. Non-medicated ADHD students recalled less of both segments than the medicated ADHD or non-ADHD groups, which did not differ from each other. ConclusionStimulants improved memory in ADHD students, and did not impair the relative retention of emotional, as opposed to neutral information. Stimulant-induced arousal cannot explain the academic deficit of ADHD undergraduates.

The Resting Electrophysiological Profile in Adults With ADHD and Comorbid Dysfunctional Anger

Although dysfunctional anger is not a Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision [DSM-IV-TR]) diagnosis, it sometimes presents as a primary clinical complaint and as a comorbid feature in a subset of adults with attention-deficit/hyperactivity disorder (ADHD). No known studies have examined electroencephalographic (EEG) profiles in adults with comorbid dysfunctional anger and ADHD (ADHD + anger). Resting EEG was recorded in 14 ADHD + anger adults (11 males) and 14 controls. Relative power was assessed at standard frequencies, as was frontal absolute α power asymmetry. A modest increase was noted in β1 power in the ADHD + anger group. Unexpectedly, relatively decreased left (or increased right) frontocortical activity (α assessed) was noted in the ADHD + anger group, which was also characterized by a more diffuse θ/β ratio scalp distribution. Nonmedicated ADHD + anger adults exhibited modest resting cortical hyperarousal, consistent with the findings in a subset of children with ADHD characterized by anger-associated problems. The unexpected frontal α asymmetry may reflect enhanced activity of frontal inhibitory mechanisms.

Salivary bacteria and oral health status in medicated and non-medicated children and adolescents with attention deficit hyperactivity disorder (ADHD)

Attention deficit hyperactivity disorder (ADHD) is a childhood neurological disorder. Studies have shown that children with ADHD are more prone to caries than those without. The study investigated children diagnosed with ADHD, both with and without pharmacological intervention, and the following: DMFT\dmft, plaque index (PI), mutans streptococci (MS) levels, lactobacilli (LB) levels, salivary flow, salivary buffer capacity, oral hygiene, and diet. DMFT/dmft index, PI, MS and LB levels, salivary flow, and salivary buffer capacity were examined in three groups of children: ADHD1-diagnosed with ADHD with no pharmacological intervention (N = 31), ADHD2-treated with medications for ADHD (N = 30), and a healthy control group (N = 30). Diet and oral health habits were assessed through questionnaires completed by parents. There were no differences in the DMFT/dmft index, MS and LB counts, salivary buffer capacity, and parent reported diet and oral health behavior between the three groups. Children with ADHD demonstrated a higher plaque index. Although children with ADHD did not report different diet and oral health behavior from children without ADHD, this group had significantly higher levels of plaque than the control group, which combined with hyposalivation may be a risk factor for caries at an older age. Medicated and non-medicated ADHD children were similar to control children in their caries rate, MS and LB counts, salivary buffer capacity, and diet and oral health behavior. They differed in the amount of plaque found on their teeth. As a group, ADHD children demonstrated hyposalivation compared with the control.

Testing Computational Models of Dopamine and Noradrenaline Dysfunction in Attention Deficit/Hyperactivity Disorder

We test our neurocomputational model of fronto-striatal dopamine (DA) and noradrenaline (NA) function for understanding cognitive and motivational deficits in attention deficit/hyperactivity disorder (ADHD). Our model predicts that low striatal DA levels in ADHD should lead to deficits in 'Go' learning from positive reinforcement, which should be alleviated by stimulant medications, as observed with DA manipulations in other populations. Indeed, while nonmedicated adult ADHD participants were impaired at both positive (Go) and negative (NoGo) reinforcement learning, only the former deficits were ameliorated by medication. We also found evidence for our model's extension of the same striatal DA mechanisms to working memory, via interactions with prefrontal cortex. In a modified AX-continuous performance task, ADHD participants showed reduced sensitivity to working memory contextual information, despite no global performance deficits, and were more susceptible to the influence of distractor stimuli presented during the delay. These effects were reversed with stimulant medications. Moreover, the tendency for medications to improve Go relative to NoGo reinforcement learning was predictive of their improvement in working memory in distracting conditions, suggestive of common DA mechanisms and supporting a unified account of DA function in ADHD. However, other ADHD effects such as erratic trial-to-trial switching and reaction time variability are not accounted for by model DA mechanisms, and are instead consistent with cortical noradrenergic dysfunction and associated computational models. Accordingly, putative NA deficits were correlated with each other and independent of putative DA-related deficits. Taken together, our results demonstrate the usefulness of computational approaches for understanding cognitive deficits in ADHD.

The effect of stimulants on sleep characteristics in children with attention deficit/hyperactivity disorder

Objective: To investigate the effects of stimulant medications on subjective and objective sleep characteristics of children with attention deficit/hyperactivity disorder (ADHD) compared with control children. Methods: An observational study in the sleep clinic and the community. Children with characteristics of ADHD, both stimulant-medicated ( n=53), and non-medicated ( n=34), together with control children ( n=53) completed a sleep habits questionnaire prior to undergoing full overnight polysomnographic assessment. Results: Medicated and non-medicated ADHD subjects were reported to have more sleep disturbances compared with controls. Both groups of ADHD children also demonstrated decreased REM sleep percentage compared with controls ( P=0.006 for ADHDmed; P=0.02 for ADHDnon). However, the use of stimulant medication ( n=53) was not associated with differences in subjective sleep quality or objective sleep measures, compared to ADHD children not taking any medication ( n=34; P=n.s.). Conclusions: Despite the high prevalence of reported sleep disturbance in children with ADHD, stimulant medication appears to have minimal effects on subjective and objective sleep characteristics in children with reported ADHD.