Neurobiological substrates of social cognition impairment in attention-deficit hyperactivity disorder: gathering insights from seven structural and functional magnetic resonance imaging studies

Neural bases of social deficits in ADHD: A systematic review. Does the Theory of Mind matter?

INTRODUCTION

The Attention Deficit Hyperactivity Disorder (ADHD) causes serious interpersonal problems from childhood to adulthood, one of them being problematic social functioning. This phenomenon in ADHD should be associated with impairments in the Theory of Mind (ToM). Therefore, understanding the neural correlates of the ToM could be crucial for helping individuals with ADHD with their social functioning. Thus, we aimed to review published literature concerning neuroanatomical and functional correlates of ToM deficits in children and adolescents with ADHD.

METHODS

We reviewed studies published between 1970 and 2023. In accordance with PRISMA guidelines, after data from three databases were collected, two authors (LN and PM) independently screened all relevant records (n=638) and consequently, both authors did the data extraction. The quality of the included studies (n=5) was measured by a modified version of The Newcastle-Ottawa Scale and by measures specific for our study. This systematic review was registered on PROSPERO (CRD42020139847).

RESULTS

Results indicated that impairments in performing of the ToM tasks were negatively associated with the grey matter volume in the bilateral amygdala and hippocampus in both, ADHD and control group. In EEG studies, a significantly greater electrophysiological activity during ToM tasks was observed in the, frontal, temporal, parietal and occipital lobes in participants with ADHD as compared to healthy subjects.

CONCLUSION

More research is needed to explore the ToM deficits in children with ADHD. Future research might focus on the neural circuits associated with attention and inhibition, which deficits seems to contribute to the ToM deficits in children and adolescents with ADHD.

A pilot study on the association between the blood oxygen level-dependent signal in the reward system and dopamine transporter availability in adults with attention deficit hyperactivity disorder

BACKGROUND

It is well-known that attention deficit hyperactivity disorder (ADHD) is associated with changes in the dopaminergic system. However, the relationship between central dopaminergic tone and the blood oxygen level-dependent (BOLD) signal during receipt of rewards and penalties in the corticostriatal pathway in adults with ADHD is unclear.

METHODS

Single-photon emission computed tomography with [99mTC]TRODAT-1 was used to assess striatal dopamine transporter (DAT) availability. Event-related functional magnetic resonance imaging was conducted on subjects performing the Iowa Gambling Test.

RESULT

DAT availability was found to be associated with the BOLD response, which was a covariate of monetary loss, in the medial prefrontal cortex (r = 0.55, P = .03), right ventral striatum (r = 0.69, P = .003), and right orbital frontal cortex (r = 0.53, P = .03) in adults with ADHD. However, a similar correlation was not found in the controls.

CONCLUSIONS

The results confirmed that dopaminergic tone may play a different role in the penalty-elicited response of adults with ADHD. It is plausible that a lower neuro-threshold accompanied by insensitivity to punishment could be exacerbated by the hypodopaminergic tone in ADHD.

ADHD Among Offenders: Prevalence and Relationship With Psychopathic Traits

Objective: Longitudinal studies have shown a strong association between ADHD and criminal behavior. The aims of this study were to examine the prevalence of adult ADHD in a high-security facility and to investigate the relationship between ADHD symptoms and psychopathic traits in criminal offenders. Material and Methods: Participants were recruited between October 2015 and January 2016 among the inmates from a high-security all-male correctional facility in Portugal. Self-report scales were used to measure ADHD symptoms, current psychopathology, and psychopathic traits. An interview was conducted to collect sociodemographic data, along with information about adverse childhood experiences, substance use, and criminal record. The statistical analysis was conducted using STATA 13 with the significance level set at .05. Results: From the final sample of 101 male prisoners, 17 participants (16.8%) screened positive for ADHD. Participants positive for ADHD had higher levels of general psychopathology and psychopathic traits. Psychopathic traits remained significantly higher in ADHD offenders after controlling for age, substance abuse, and early childhood adversities (OR = 1.07, p = .002) and this was explained by differences in the Meanness subscale (OR = 1.11, p = .013). Discussion/conclusions: The present study shows that ADHD symptoms are highly prevalent among offenders and might have a modulating effect on the course of delinquent behavior. The cross-sectional association between ADHD symptoms and psychopathic traits reinforces the previously documented correlation between these disorders and can lead to a better understanding of the prevalent criminal behavior in ADHD patients.

MRI Evidence of Neuropathic Changes in Former College Football Players

OBJECTIVE

To examine effects of participating in collegiate football on neural health several years after retirement. We hypothesized that relative cortical thinning and loss of white matter integrity would be observed in former players.

DESIGN

Former NCAA Division I football players were compared with demographically similar track-and-field athletes with regard to cortical thickness and white matter integrity.

SETTING

Participants participated in MRI scans at the Center for Imaging Research at the University of Cincinnati.

PARTICIPANTS

Eleven former football players and 10 demographically similar track-and-field athletes.

MAIN OUTCOME MEASURES

Normalized cortical thickness was compared between groups using 2-tailed Student t test. As a secondary analysis, Spearman correlation coefficient was calculated between cortical thickness and number of concussions. Fractional anisotropy for regions-of-interest placed in frontal white matter tracts and internal capsule were compared between groups using 2-tailed Student t test.

RESULTS

Football players showed significantly lower cortical thickness within portions of both the frontal and temporal cortex. Affected frontal regions included left frontal pole and right superior frontal gyrus. Affected temporal regions included portions of the superior temporal gyrus, left inferior temporal gyrus, and right middle and superior temporal gyri. Cortical thickness inversely correlated with number of reported concussions over most of these regions. In addition, fractional anisotropy was lower in the right internal capsule of former football players, relative to controls.

CONCLUSIONS

These findings suggest that at least some consequences of high-level collegiate football play persist even after the cessation of regular head blows. Longer-term studies are warranted to examine potential cognitive and functional implications of sustained cortical atrophy.

Impaired Social Decision-Making Mediates the Association Between ADHD and Social Problems

Attention-deficit/hyperactivity disorder (ADHD) reliably predicts social dysfunction, ranging from poor social competence and elevated peer rejection to inadequate social skills. Yet, the factors mediating predictions of social problems from childhood ADHD are not well understood. In the present study, we investigated social functioning in 186 (69 % male) 6 to 10 year-old (M = 7.88, SD = 1.17) children with (n = 98) and without (n = 87) ADHD who were followed prospectively for two years. We implemented a well-validated measure of social problems as well as a novel social decision-making task assessing dynamic response to changing affective cues at the two-year follow-up. According to separate parent and teacher report, baseline ADHD symptoms positively predicted social problems at the two-year follow-up; individual differences on the social decision-making task mediated this association. This finding was replicated when ADHD dimensions (i.e., inattention and hyperactivity/impulsivity) were separately examined. These findings suggest that the deficient use of affective cues to effectively guide behavior may partially underlie poor social functioning among children with ADHD. If replicated, these preliminary findings suggest that social skills interventions that target interpretation of affective cues to aid in social decision-making behavior may improve social outcomes negatively affected by early ADHD symptoms.

Executive and attentional contributions to Theory of Mind deficit in attention deficit/hyperactivity disorder (ADHD)

Attention deficit/hyperactivity disorder (ADHD) in children has been associated with attentional and executive problems, but also with socioemotional difficulties possibly associated with deficits in Theory of Mind (ToM). Socioemotional problems in ADHD are associated with more negative prognoses, notably interpersonal, educational problems, and an increased risk of developing other psychiatric disorders that emphasize the need to clarify the nature of their ToM deficits. In this study, we hypothesized that ToM dysfunction in children with ADHD is largely attributable to their attentional and/or executive deficits. Thirty-one children with ADHD (8-12 years, IQ > 85) and 31 typically developing (TD) children were assessed using executive functions (inhibition, planning, and flexibility) and attentional tasks, as well as two advanced ToM tasks (Reading the Mind in the Eyes and Faux Pas) involving different levels of executive control. Children with ADHD performed more poorly than TD children in attentional, executive function, and ToM tasks. Linear regression analyses conducted in the ADHD group indicated that inhibition scores predicted performance on the "Faux Pas" task the best, while attention scores were the best for predicting performance on the Reading the Mind in the Eyes task. When controlled for inhibition and attentional variables, ToM performance in children with ADHD was actually similar to TD children. Contrarily, controlling for ToM scores did not normalize performance for inhibition and attentional tasks in children with ADHD. This unidirectional relationship suggests that deficits in the EF and attentional domains are responsible for ToM deficits in ADHD, which therefore may contribute to their socioemotional difficulties.

Facial emotion recognition in male antisocial personality disorders with or without adult attention deficit hyperactivity disorder

OBJECTIVE

We aimed to investigate facial emotion recognition abilities in violent individuals with antisocial personality disorder who have comorbid attention deficient hyperactivity disorder (ADHD) or not.

METHOD

The photos of happy, surprised, fearful, sad, angry, disgust, and neutral facial expressions and Wender Utah Rating Scale have been performed in all groups.

RESULTS

The mean ages were as follows: in antisocial personality disorder with ADHD 22.0 ± 1.59, in pure antisocial individuals 21.90 ± 1.80 and in controls 22.97 ± 2.85 (p>0.05). The mean score in Wender Utah Rating Scale was significantly different between groups (p<0.001). The mean accurate responses to each facial emotion between groups were insignificant (p>0.05) excluding disgust faces which was significantly impaired in ASPD+ADHD and pure ASPD groups. Antisocial individuals with attention deficient and hyperactivity had spent significantly more time to each facial emotion than healthy controls (p<0.05) while pure antisocial individual had more time to recognize disgust and neutral faces than healthy controls (p<0.05).

CONCLUSION

Study of complex social cognitive abilities in adults with ADHD and violent behaviors is lacking. This study is the first, investigating the differences according to social cognition cues in violent individual that revealed no significance within pure antisocial individuals and antisocial individuals with ADHD.

Treadmill exercise ameliorates symptoms of attention deficit/hyperactivity disorder through reducing Purkinje cell loss and astrocytic reaction in spontaneous hypertensive rats

Attention deficit/hyperactivity disorder (ADHD) is a neurobehavioral disorder of cognition. We investigated the effects of treadmill exercise on Purkinje cell and astrocytic reaction in the cerebellum of the ADHD rat. Adult male spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKYR) weighing 210± 10 g were used. The animals were randomly divided into four groups (n= 15): control group, ADHD group, ADHD and methylphenidate (MPH)-treated group, ADHD and treadmill exercise group. The rats in the MPH-treated group as a positive control received 1 mg/kg MPH orally once a day for 28 consecutive days. The rats in the treadmill exercise group were made to run on a treadmill for 30 min once a day for 28 days. Motor coordination and balance were determined by vertical pole test. Immunohistochemistry for the expression of calbindinD-28 and glial fibrillary acidic protein (GFAP) in the cerebellar vermis and Western blot for GFAP, Bax, and Bcl-2 were conducted. In the present results, ADHD significantly decreased balance and the number of calbindin-positive cells, while GFAP expression and Bax/Bcl-2 ratio in the cerebellum were significantly increased in the ADHD group compared to the control group (P< 0.05, respectively). In contrast, treadmill exercise and MPH alleviated the ADHD-induced the decrease of balance and the number of calbindine-positive cells, and the increase of GFAP expression and Bax/Bcl-2 ratio in the cerebellum (P< 0.05, respectively). Therefore, the present results suggested that treadmill exercise might exert ameliorating effect on ADHD through reduction of Purkinje cell loss and astrocytic reaction in the cerebellum.

Cognitive variability in adults with ADHD and AS: disentangling the roles of executive functions and social cognition

Attention-deficit/hyperactivity disorder (ADHD) and Asperger's Syndrome (AS) share a heterogeneous cognitive profile. Studies assessing executive functions (EF) and social cognition in both groups have found preserved and impaired performances. These inconsistent findings would be partially explained by the cognitive variability reported in these disorders. First, the present study explored the inter-individual variability in EF and social cognition in both patient groups. Second, we compared differential characteristics and commonalities in the cognitive profiles of EF and social cognition between ADHD, AS and control adults. We assessed 22 patients with ADHD, 23 adults with AS and 21 matched typically developing subjects using different measures of EF (working memory, cognitive flexibility and multitasking) and social cognition (theory of mind and decision-making). Group comparisons and multiple case series analyses (MCSA) were conducted. The between-group comparisons showed an EF deficit in working memory in ADHD and a theory of mind (ToM) impairment in AS. The MCSA evidenced that, compared to controls, ADHD patients had a higher inter-individual variability in EF, while individuals with AS had a more heterogeneous profile in social cognition tasks compared to both groups. Finally, the AS and ADHD groups presented higher task-related variability compared to controls and shared a common heterogeneous profile in EF. This is the first study to compare variability in EF and social cognition profiles of ADHD and AS. We propose that heterogeneity in EF performance is a link between ADHD and AS which may explain the overlap of symptomatology between both diagnoses. In addition, patients with AS seem to show a unique heterogeneous profile in ToM which may explain the low probability of finding AS symptoms in patients with ADHD.

Genetic variations of the melatonin pathway in patients with attention-deficit and hyperactivity disorders

Melatonin is a powerful antioxidant and a synchronizer of many physiological processes. Alteration in melatonin signaling has been reported in a broad range of diseases, but little is known about the genetic variability of this pathway in humans. Here, we sequenced all the genes of the melatonin pathway -AA-NAT, ASMT, MTNR1A, MTNR1B and GPR50 - in 321 individuals from Sweden including 101 patients with attention-deficit/hyperactivity disorder (ADHD) and 220 controls from the general population. We could find several damaging mutations in patients with ADHD, but no significant enrichment compared with the general population. Among these variations, we found a splice site mutation in ASMT (IVS5+2T>C) and one stop mutation in MTNR1A (Y170X) - detected exclusively in patients with ADHD - for which biochemical analyses indicated that they abolish the activity of ASMT and MTNR1A. These genetic and functional results represent the first comprehensive ascertainment of melatonin signaling deficiency in ADHD.

[The training of social skills in children with ADHD - results of a pilot study]

OBJECTIVE

Insufficient social competence belongs to the most frequent concomitants of ADHD. This is the first therapeutic concept for the training of social skills adapted to the specific deficits of children with ADHD and developed in the German-speaking region.

METHOD

In a two-group, pre-posttest design with untreated waiting control group, 40 children between 7 and 13 years with the diagnoses F90.0, F90.1, and F98.8 were examined; 15 % were female, 85 % male. In groups of three they took part in the newly developed 10-h training TEAM. The record sheet of social skills for parents (ESF-E) was used to measure social competence. In addition, we recorded attention performances (FBB ADHS) and concomitant psychic factors.

RESULTS

Significant effects of the training were demonstrated for almost all social skills (MANOVA/GLM). The outcomes on the different components of attention and the psychosocial concomitant factors are without uniformity. The strongest effects appeared in the areas of conflict management, regulation of emotions, and the capacity for empathy.

CONCLUSIONS

Training of social skills is a sensible and effective supplement in the therapy of ADHD. An examination of long-term effects still needs to be done.

Repetitive behavior and increased activity in mice with Purkinje cell loss: a model for understanding the role of cerebellar pathology in autism

Repetitive behaviors and hyperactivity are common features of developmental disorders, including autism. Neuropathology of the cerebellum is also a frequent occurrence in autism and other developmental disorders. Recent studies have indicated that cerebellar pathology may play a causal role in the generation of repetitive and hyperactive behaviors. In this study, we examined the relationship between cerebellar pathology and these behaviors in a mouse model of Purkinje cell loss. Specifically, we made aggregation chimeras between Lc/+ mutant embryos and +/+ embryos. Lc/+ mice lose 100% of their Purkinje cells postnatally due to a cell-intrinsic gain-of-function mutation. Through our histological examination, we demonstrated that Lc/+<-->+/+ chimeric mice have Purkinje cells ranging from zero to normal numbers. Our analysis of these chimeric cerebella confirmed previous studies on Purkinje cell lineage. The results of both open-field activity and hole-board exploration testing indicated negative relationships between Purkinje cell number and measures of activity and investigatory nose-poking. Additionally, in a progressive-ratio operant paradigm, we found that Lc/+ mice lever-pressed significantly less than +/+ controls, which led to significantly lower breakpoints in this group. In contrast, chimeric mice lever-pressed significantly more than controls and this repetitive lever-pressing behavior was significantly and negatively correlated with total Purkinje cell numbers. Although the performance of Lc/+ mice is probably related to their motor deficits, the significant relationships between Purkinje cell number and repetitive lever-pressing behavior as well as open-field activity measures provide support for a role of cerebellar pathology in generating repetitive behavior and increased activity in chimeric mice.

Social cognition in attention-deficit hyperactivity disorder (ADHD)

Attention-deficit hyperactivity disorder (ADHD) is associated with a range of cognitive deficits and social cognition impairments, which might be interpreted in the context of fronto-striatal dysfunction. So far only few studies have addressed the issue of social cognition deficits in ADHD.

METHOD

Medline and Psyclit searches were performed for a 30-year period (1979-2009) using the words 'ADHD' and 'social cognition', 'theory of mind', 'prosody', 'face perception', 'humour' or 'social information processing'. Inclusion criteria consisted of a diagnosis according to DSM as well as the inclusion of a control group or a follow-up assessment following the treatment with methylphenidate.

RESULTS

ADHD is clearly associated with social cognition impairments involving emotional face and prosody perception. Although the database is sparse so far, there is some evidence for theory of mind deficits and reduced empathy in ADHD.

CONCLUSIONS

In summary, the social cognition impairments are consistent with fronto-striatal dysfunction in ADHD, but other functional networks of brain areas also appear to be implicated.