Association Between Continuous Performance and Response Inhibition Tests in Adults With ADHD

Mental Health in Adults With ADHD: Examining the Relationship With Cardiorespiratory Fitness

OBJECTIVE

The mental health of adults with ADHD was compared to neurotypical controls, and associations between cardiorespiratory fitness (CRF) and mental health were examined.

METHOD

Seventy-two participants (n = 36 with ADHD) completed demographic questions assessing ADHD and mental health symptoms. CRF was estimated using the 6-Minute Walk Test and a self-perception question.

RESULTS

Those with ADHD had significantly poorer mental health outcomes than controls (p < .001), with 50% of adults with ADHD reporting moderate to extremely severe symptoms of depression, anxiety, and stress. Critically, lower CRF was associated with worse depression, anxiety, and stress (all p ≤ .03) across both groups. Within the ADHD group, those with higher estimated CRF had significantly lower stress. Among participants with less severe ADHD symptoms, those with higher perceived CRF had significantly lower depressive symptoms.

CONCLUSION

In our cross-sectional study, participants with ADHD had poorer mental health than neurotypical controls, and higher fitness was associated with better mental health.

Effect of Distractors on Sustained Attention and Hyperactivity in Youth With Attention Deficit Hyperactivity Disorder Using a Mobile Virtual Reality School Program

OBJECTIVE

This study examined whether distractors in virtual reality (VR) environment affected the attention and hyperactivity in children and adolescents with ADHD.

METHOD

A total of 40 students (21 ADHD, 19 controls) aged between 9 and 17 years participated in this study. A rapid visual information processing task utilizing VR (VR-RVP) was performed under two conditions (no-distractor and distractor condition). Task performance and head movement during each condition were compared, and additional analyses were conducted after grouping participants into two developmental stages.

RESULTS

Children with ADHD performed comparably to the controls under the distractor condition, but had poorer performance under the no-distractor condition. They displayed more head movement under the distractor condition than in the no-distractor condition.

CONCLUSION

VR is possibly a useful tool for investigating the effect of distractors on individuals with ADHD, and children with ADHD are more vulnerable to a low-level stimulation situation than normal children in VR.

High-gamma oscillations as neurocorrelates of ADHD: A MEG crossover placebo-controlled study

Attention Deficit Hyperactive Disorder (ADHD) is a common neurobehavioral disorder with a significant and pervasive impact on patients' lives. Identifying neurophysiological correlates of ADHD is important for understanding its underlying mechanisms, as well as for improving clinical accuracy beyond cognitive and emotional factors. The present study focuses on finding a diagnostic stable neural correlate based on evaluating MEG resting state frequency bands. Twenty-two ADHD patients and 23 controls adults were blindly randomized to two methylphenidate/placebo evaluation days. On each evaluation day state anxiety was assessed, a 2N-back executive function task was performed, and resting state MEG brain activity was recorded at three timepoints. A frequency-based cluster analysis yielded higher high-gamma power for ADHD over posterior sensors and lower high-gamma power for ADHD over frontal-central sensors. These results were shown to be stable over three measurements, unaffected by methylphenidate treatment, and linked to cognitive accuracy and state anxiety. Furthermore, the differential high-gamma activity evidenced substantial ADHD diagnostic efficacy, comparable to the cognitive and emotional factors. These results indicate that resting state high-gamma activity is a promising, stable, valid and diagnostically-relevant neurocorrelate of ADHD. Due to the evolving understanding both in the cellular and network level of high-gamma oscillations, focusing future studies on this frequency band bears the potential for a better understanding of ADHD, thus advancing the specificity of the evaluation of the disorder and developing new tools for therapy.

Is sustained attention deficit related to subclinical obsessive thoughts in children and adolescents with ADHD?

Background: Thought content and its impact on sustained attention in individuals with attention deficit hyperactivity disorder (ADHD) are topics of growing interest in literature.Objective: We hypothesised that subclinical obsessive thoughts may be correlated with attention lapses in individuals with ADHD.Method: Thirty children diagnosed with ADHD participated in the study and their level of subclinical obsessive thoughts, attention, and executive function were measured using Children Yale-Brown Obsessive Scale and Conners' Continuous Performance Test II.Results: No significant correlation between sustained attention impairment and the level of obsessive thoughts in patients with ADHD was found. Nevertheless, patients with ADHD with subclinical obsessive thoughts showed more commission errors than those without (W = 51.5; p = 0.02).Conclusion: The nature of thought content in individuals with ADHD should be linked to executive dysfunction rather than attentional impairment. This could be of importance in the therapeutic strategy choice, addressing the importance of executive function remediation in the specific context of subclinical obsessive thoughts.Key points Patients with ADHD, without OCD or ASD comorbidity, still present subclinical obsessive thoughts (36% of our sample).  • Subclinical obsessive thoughts could be a part of thought content in patients with ADHD. • Subclinical obsessive thoughts as measured by the CPT-II are not correlated with attention function in patients with ADHD. • ADHD patients with subclinical obsessive symptoms present more impairment in response inhibition than the ones without. • Results on subclinical obsessive thoughts are similar to those on another type of thought content called 'mind wandering'. • A clinical improvement strategy for patients with ADHD could be using executive function remediation rather than classical attention function remediation, according to both to our and previous results.

The interactive effects of test-retest and methylphenidate administration on cognitive performance in youth with ADHD: A double-blind placebo-controlled crossover study

Studies have shown that Methylphenidate (MPH) affects cognitive performance on the neuropsychological tests and clinical symptoms of individuals diagnosed with attention deficit/hyperactivity disorder (ADHD). This study investigated the acute effects of MPH on neuropsychological tests to explore the interaction between MPH and test-retest effects. Twenty youths with ADHD were tested before and after MPH intake in a double-blind placebo-controlled crossover design and compared to twenty matched controls. Participants were tested on a range of standardized tasks including sustained attention to response, N-Back, and Word/Color Stroop. Identical tasks were administered twice each testing day, before and 1 hour after MPH/Placebo administration. Healthy controls were tested similarly with no intervention. Decreases in response time (RT) variability across tasks and in commission errors were found in ADHD after MPH. Conversely, a significant increase in RT variability and increase in omission errors were observed after the placebo. In the control group, RT variability and omission errors increased whereas commission errors decreased, suggesting fatigue and practice effects, respectively. Test-retest reliability was higher in controls than ADHD. It is suggested that cognitive tests are sensitive objective measures for the assessment of responses to MPH in ADHD but are also affected by repetition and fatigue.

Association Between Auditory and Visual Continuous Performance Tests in Students With ADHD

OBJECTIVE

Continuous Performance Tests (CPTs) are known to measure inattention and impulsivity in students with ADHD. Many CPTs utilize a visual format. It is accepted that auditory tasks reflect attentional demand more closely in the classroom. Thus, the association between deficits found by auditory and visual CPTs needs to be studied. We hypothesized that impulsivity would be dependent on sensory modality and inattention would be a unitary cross-modal construct.

METHOD

Forty-four students with ADHD performed two CPTs (visual and auditory). We analyzed correlations between the variables examined by the two tasks.

RESULTS

There were strong correlations between variables measuring inattention. Correlations between auditory and visual measures of impulsivity were weak.

CONCLUSION

Inattention is partially independent of modality. In contrast, response inhibition is modality-specific. Although ADHD is defined regardless of modality, hyperactive students may exhibit deficits in the auditory modality but not in the visual modality or vice versa.

Linking ADHD to the Neural Circuitry of Attention

Attention deficit hyperactivity disorder (ADHD) is a complex condition with a heterogeneous presentation. Current diagnosis is primarily based on subjective experience and observer reports of behavioral symptoms - an approach that has significant limitations. Many studies show that individuals with ADHD exhibit poorer performance on cognitive tasks than neurotypical controls, and at least seven main functional domains appear to be implicated in ADHD. We discuss the underlying neural mechanisms of cognitive functions associated with ADHD, with emphasis on the neural basis of selective attention, demonstrating the feasibility of basic research approaches for further understanding cognitive behavioral processes as they relate to human psychopathology. The study of circuit-level mechanisms underlying executive functions in nonhuman primates holds promise for advancing our understanding, and ultimately the treatment, of ADHD.

How can Continuous Performance Test help to assess inattention when mood and ADHD symptoms coexist?

Depression and attention-deficit/hyperactivity disorder (ADHD) are prevalent, and often comorbid, disorders, with varying severity levels among patients. Inattention is a symptom present in both disorders, which often makes their differential diagnosis difficult in clinical practice (depression only versus comorbidity). This study aimed to investigate the influence of depressive symptoms on attention performance using one of the most common tasks in clinical practice, the continuous performance test (CPT). Ninety-three college students (60 men, 33 women) with a mean age of 24 years old were investigated with self-reports and semi-structured interviews for ADHD; the Beck Depression Inventory (BDI) was used for depression ratings. Attention measures were derived from the CPT. There was no correlation between depression and ADHD symptoms; in addition, depression was not correlated with any of the CPT scores; ADHD symptomatology was the only predictor of changes in those CPT variables (commission and omission errors and d prime). ADHD-associated impairment on the CPT was not augmented by the presence of depressive symptoms, making neuropsychological results on this test helpful for the differential diagnosis. When attention deficits are observed in individuals with mild or moderate depression, they are most likely not attributed to depression.

Behavior, neuropsychology and fMRI

Cognitive neuroscientists in the late 20th century began the task of identifying the part(s) of the brain concerned with normal behavior as manifest in the psychological capacities as affective powers, reasoning, behaving purposively and the pursuit of goals, following introduction of the 'functional magnetic resonance imaging' (fMRI) method for identifying brain activity. For this research program to be successful two questions require satisfactory answers. First, as the fMRI method can currently only be used on stationary subjects, to what extent can neuropsychological tests applicable to such stationary subjects be correlated with normal behavior. Second, to what extent can correlations between the various neuropsychological tests on the one hand, and sites of brain activity determined with fMRI on the other, be regarded as established. The extent to which these questions have yet received satisfactory answers is reviewed, and suggestions made both for improving correlations of neuropsychological tests with behavior as well as with the results of fMRI-based observations.