Reward modality modulates striatal responses to reward anticipation in ADHD: Effects of affiliative and food stimuli

Altered reward sensitivity has been proposed to underlie symptoms of attention deficit hyperactivity disorder (ADHD). Functional magnetic resonance imaging (fMRI) studies have reported hypoactivation to reward-predicting cues in the ventral striatum among individuals with ADHD, using experimental designs with and without behavioral response requirements. These studies have typically used monetary incentives as rewards; however, it is unclear if these findings extend to other reward types. The current study examined striatal responses to anticipation and delivery of both affiliative and food reward images using a classical conditioning paradigm. Data from 20 typically developing young adults, and 20 individuals diagnosed with ADHD were included in a region-of-interest analysis for a priori striatal regions. Consistent with findings from studies using monetary rewards, individuals with ADHD showed decreased activation to cues predicting affiliative rewards in the bilateral ventral and dorsal striatum and increased activation to the delivery of affiliative rewards in the ventral striatum. No group differences were found in striatal responses to food reward cues or images. These results suggest hyposensitivity to reward-predicting cues in ADHD extends to affiliative rewards, with important implications for understanding and managing the learning and social functioning of those with ADHD.

Network analysis of narrative discourse and attention-deficit hyperactivity symptoms in adults

Previous research investigating language in attention-deficit hyperactivity disorder (ADHD) has demonstrated several deficits in many aspects. However, no previous study employed quantitative methodology providing objective measures that could be compared among different studies with diverse samples. To fill this gap, we used network analysis to investigate how ADHD symptomatology impacts narrative discourse, a complex linguistic task considered to be an ecological measure of language. Fifty-eight adults (34 females and 24 males) with a mean age of 26 years old and a mean of 17 years of educational level were administered the Adult Self-Rating Scale for ADHD symptomatology. They also completed the State-Trait Anxiety Inventory, the Beck Depression Inventory and the Urgency, Premeditation, Perseverance, Sensation Seeking Behavior Scale. Intelligence quotient was calculated. Individuals were asked to tell a story based on a wordless picture book. Speech was recorded and transcribed as an input to SpeechGraphs software. Parameters were total number of words (TNW), number of loops of one node (L1), repeated edges (RE), largest strongly connected component (LSC) and average shortest path (ASP). Verbosity was controlled. Statistical analysis was corrected for multiples comparisons and partial correlations were performed for confounding variables. After controlling for anxiety, depression, IQ, and impulsiveness ADHD symptomatology was positively correlated with L1 and negatively correlated with LSC. TNW was positively correlated with ADHD symptoms. In a subdomain analysis, both inattention and hyperactivity-impulsivity were negatively correlated with LSC. Only hyperactivity-impulsivity positively correlated with TNW and L1. Results indicated a correlation between ADHD symptoms and lower connectedness in narrative discourse (as indicated by higher L1 and lower LSC), as well as higher total number of words (TNW). Our results suggest that the higher the number of ADHD symptoms, the less connectivity among words, and a higher number of words in narrative discourse.

Impulsivity as an Endophenotype in ADHD: Negative Findings

Impulsivity has a strong genetic component and is considered an endophenotype in many psychiatric disorders. Impulsivity in adult ADHD has become a focus of interest more recently because of its suggested prominence in this age. Objective: This study aimed to access self-reported impulsivity levels in biological parents of ADHD offspring, according to their status: non-ADHD (controls), remitted, nonremitted. Method: Impulsivity levels of 155 parents of ADHD children were compared according to their status using the Barratt Impulsiveness Scale (BIS-11). Results: The ADHD group presented the highest levels of impulsivity compared with all other groups. The remitted ADHD and control groups showed no significant differences in impulsivity levels. Conclusion: Impulsivity tended to remit alongside ADHD symptoms in remitters and to persist in those presenting with the residual form of adult ADHD suggesting it should not be considered as an endophenotype. Only the attentional dimension was impaired, cautioning against Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) impulsivity proposed criteria.

Mild Cognitive Impairment or Attention-Deficit/Hyperactivity Disorder in Older Adults? A Cross Sectional Study

Background: Attention-Deficit/Hyperactivity Disorder (ADHD) is a highly prevalent neurodevelopmental condition, which may be associated with life-enduring cognitive dysfunction. It has been hypothesized that age-related cognitive decline may overlap with preexisting deficits in older ADHD patients, leading to increased problems to manage everyday-life activities. This phenomenon may mimic neurodegenerative disorders, in particular Mild Cognitive Impairment (MCI). This cross-sectional study aims to assess cognitive and behavioral differences between older subjects with ADHD and MCI. Methods: A total of 107 older participants (41 controls; 40 MCI and 26 ADHD; mean age = 67.60 ± 7.50 years; mean schooling = 15.14 ± 2.77 years; 65.4% females) underwent clinical, cognitive, and behavioral assessments by a multidisciplinary team at the Memory Clinic, D'Or Institute for Research and Education, Rio de Janeiro, Brazil. Mean scores in neuropsychological tasks and behavioral scales were compared across groups. Results: Participants with ADHD showed poorer performances than controls in episodic memory and executive function with large effect-sizes. Performances were comparable between MCI and ADHD for all domains. Discussion: MCI and ADHD in older individuals are dissociated clinical entities with overlapping cognitive profiles. Clinicians ought to be aware of these converging phenotypes to avoid misdiagnosis.

Mind-wandering, depression, anxiety and ADHD: Disentangling the relationship

BACKGROUND

Mind Wandering (MW) has been associated with ADHD in a very small number of studies with adults and children. However, anxiety and depression have also been associated with MW and both are often comorbid with ADHD. The aim of this study was to investigate the role of anxiety and depression in MW in patients with ADHD.

METHODS

The Mind Excessively Wandering Scale (MEWS) compared the levels of MW controlling for the presence of anxiety and depression symptoms in 78 adolescents (53 males and 25 females) comprising ADHD, clinical controls and typically developing individuals. Correlational analysis between MEWS score, demographic variables, ADHD, anxiety and depressive symptoms was performed using simple and multiple linear regression analysis demonstrating that only anxiety predicted MW scores. On a second analysis, we compared Anxiety and Non-Anxiety as well as ADHD and non-ADHD groups.

RESULTS

Levels of MW were significantly correlated with anxiety symptoms, but not with depression. In addition, there were no differences in ADHD and non-ADHD groups regarding MW levels.

CONCLUSIONS

Our results suggest MW is associated with anxiety levels, independently of an ADHD diagnosis.

Inter-method and anatomical correlates of episodic memory tests in the Alzheimer's Disease spectrum

Background

Episodic memory impairments have been described as initial clinical findings in the Alzheimer’s Disease (AD) spectrum, which could be associated with the presence of early hippocampal dysfunction. However, correlates between performances in neuropsychological tests and hippocampal volumes in AD were inconclusive in the literature. Divergent methods to assess episodic memory have been depicted as a major source of heterogeneity across studies.

Methods

We examined correlates among performances in three different delayed-recall tasks (Rey-Auditory Verbal-Learning Test–RAVLT, Logical Memory and Visual Reproduction subtests from the Wechsler Memory Scale) and fully-automated volumetric measurements of the hippocampus (estimated using Neuroquant^®) of 83 older subjects (47 controls, 27 Mild Cognitive Impairment individuals and 9 participants with Dementia due to AD).

Results

Inter-method correlations of episodic memory performances were at most moderate. Scores in the RAVLT predicted up to 48% of variance in HOC (Hippocampal Occupancy Score) among subjects in the AD spectrum.

Discussion

Tests using different stimuli (verbal or visual) and presenting distinct designs (word list, story or figure learning) may assess divergent aspects in episodic memory, with heterogeneous anatomical correlates.

Conclusions

Different episodic memory tests might not assess the same construct and should not be used interchangeably. Scores in RAVLT may correlate with the presence of neurodegeneration in AD.

Transcultural adaptation to Portuguese of the Mind Excessively Wandering Scale (MEWS) for evaluation of thought activity

Abstract Introduction: The concept of mind wandering refers to periods during which attention and content of thoughts depart from the original idea or activity being performed. The phenomenon occurs commonly in the general population and the Mind Wandering Excessively Scale (MEWS) evaluates its frequency, intensity and related negative outcomes. Objective: To describe the cross-cultural adaptation of the MEWS. Methods: Cross-cultural adaptation of the original scale followed five consecutive steps: translation, backtranslation, appreciation of semantic equivalence and administration to a convenience sample to 20 adults with attention deficit hyperactivity disorder (ADHD) and 20 normal controls. Results: Results indicated a satisfactory equivalence between the original and translated versions. A synthesis version for Brazilian Portuguese is presented. Conclusions: MEWS provides information on thought activity, which is particularly important in ADHD cases. The Brazilian Portuguese version would be welcome to address specific treatment responses and obtain new outcome measures