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

Pediatric Stroke Impairs Theory of Mind Performance

AIM

This pilot study explored whether childhood stroke impairs performance on theory of mind (ToM) tasks and whether ToM task performance correlates with resting state connectivity in brain regions linked with social cognition.

METHOD

We performed a case-control study of 10 children with stroke and 10 age- and gender-matched controls. They completed 2 ToM tasks, and resting state connectivity was measured with functional magnetic resonance imaging (MRI).

RESULTS

Children with stroke performed worse than controls on conative ToM tasks. Resting state connectivity in the central executive network was significantly higher and connectivity between right and left inferior parietal lobules was significantly decreased in children with stroke. Resting state activity and ToM performance were not significantly correlated.

INTERPRETATION

Childhood stroke results in poorer performance on specific ToM tasks. Stroke is associated with changes in resting state connectivity in networks linked with social cognition including ToM. Although the basis for these changes in connectivity is not well understood, these results may provide preliminary insights into potential mechanisms affecting social cognition after stroke. The findings suggest that further study of the effect of childhood stroke on network connectivity may yield insights as to how stroke affects cognitive functions in children.

Functional connectivity of specific brain networks related to social and communication dysfunction in adolescents with attention-deficit hyperactivity disorder

BACKGROUND

Adolescents with attention-deficit hyperactivity disorder (ADHD) may have impaired social cognition and communication. However, the functioning of the brain networks involved in the social cognition and communication impairment in ADHD patients remains unclear.

METHODS

In total, 18 adolescents with ADHD and 16 age- and sex-matched typically developing adolescents (controls)-all of whom underwent a brain magnetic resonance imaging examination-were enrolled. Their parents filled out Swanson, Nolan, and Pelham IV (SNAP-IV) and Social Responsiveness Scale (SRS) questionnaires. Functional connectivity analyses based on the default mode network, frontoparietal network, and cinguloopercular network were performed.

RESULTS

Compared with controls, adolescents with ADHD exhibited higher total and subscale scores on SNAP-IV and SRS. Higher SNAP-IV and SRS scores were associated with higher functional connectivity between the default mode network (ventromedial prefrontal cortex) and cinguloopercular network (anterior insula) and between the FPN (dorsolateral and prefrontal cortex) and cinguloopercular network, but with lower functional connectivity between the default mode network (posterior cingulate cortex) and frontoparietal network (inferior parietal lobule) and between the default mode network (precuneus) and cinguloopercular network (temporoparietal junction).

DISCUSSION

Social cognition and communication impairment and ADHD may commonly share the aberrant functional connectivity in the default mode network, frontoparietal network, and cinguloopercular network.

A new semi-nonverbal task glance, moderate role of cognitive flexibility in ADHD children's theory of mind

Introduction: Studies have documented both executive functions (EF) impairment in children with Attention Deficit / Hyperactivity Disorders (ADHD) and Theory of Mind (ToM), yielding mixed results, possibly because of a variety of tasks used, all requiring different levels of language skills.Aim: To investigate the relationship between ToM and EF with non-language-based tasks.Methods: Thirty ADHD (7-9 years old) were compared to thirty controls (age and IQ matched). Participants' ToM was assessed using the Animated Triangles task and two EF tasks, namely spatial control test, the Stockings Of Cambridge (SOC) and rule and acquisition test, the Intra-Extra Dimensional set shift (IED)-from the neuropsychological battery of the Cambridge Neuropsychological Test Automated Battery (CANTAB).Results: ADHD group had a significant ToM and EF impairment relative to the control group. ToM was not significantly correlated with EF; however, the performance on IED tasks affected the performance on ToM tasks.Discussion: The study provides evidence for a link between the abilities to attribute correct mental states to others, planning and shifting attention in ADHD children, suggesting the ability to rely on cognitive flexibility in the face of a changing environment plays a role in explaining the association between ToM and EF.

Impaired empathy but no theory of mind deficits in adult attention deficit hyperactivity disorder

OBJECTIVE

The cognitive capacity to change perspective is referred to as theory of mind (ToM). ToM deficits are detectable in a variety of psychiatric and neurological disorders. Since executive abilities are closely associated with ToM skills, we suspected that due to a common neuropsychological basis, ToM deficits exist in treatment-naïve adults with attention-deficit/hyperactivity disorder (ADHD).

METHODS

Performance of treatment-naïve adults with ADHD (N = 30) in tasks assessing executive functions (Trail Making Test, Stroop color-word test, and Test Battery for Attentional Performance), empathy skills (Cambridge Behaviour Scale), and ToM (Movie for Assessment of Social Cognition) was compared with that of a healthy control group (N = 30) matched according to basic demographic variables.

RESULTS

Compared to healthy controls, treatment-naïve adults with ADHD showed deficits in various executive functions and the ability to empathize (all p < .05). However, no performance differences were found with regard to ToM (all n.s.).

CONCLUSIONS

Since studies in juveniles with ADHD often show impaired ToM performance, it is conceivable that ToM deficits may become attenuated due to neuronal development in adolescence. Furthermore, our findings imply that ToM impairments, even when present in adult ADHD, appear to be independent of executive deficits and might be explained by comorbid disorders.

Theory of Mind and Empathy in Children With ADHD

Objective: The current study compared empathy and theory of mind (ToM) between children with ADHD and healthy controls, and assessed changes in ToM among children with ADHD following administration of methylphenidate (MPH). Method: Twenty-four children with ADHD (mean age = 10.3 years) were compared with 36 healthy controls. All children completed the interpersonal reactivity index (IRI), a self-reported empathy questionnaire, and performed the "faux-pas" recognition task (FPR). Children with ADHD performed the task with and without MPH. Results: Children with ADHD showed significantly lower levels of self-reported empathy on most IRI subscales. FPR scores were significantly lower in children with ADHD and were improved, following the administration of MPH, to a level equal to that found in healthy controls. Conclusion: Children with ADHD show impaired self-reported empathy and FPR when compared with healthy controls. Stimulants improve FPR in children with ADHD to a level equal to that in healthy controls.

Selective Pragmatic Impairment in Autism Spectrum Disorder: Indirect Requests Versus Irony

Autism Spectrum Disorder (ASD) is often described as being characterised by a uniform pragmatic impairment. However, recent evidence suggests that some areas of pragmatic functioning are preserved. This study seeks to determine to which extent context-based derivation of non-linguistically encoded meaning is functional in ASD. We compare the performance of 24 adults with ASD, and matched neuro-typical adults in two act-out pragmatic tasks. The first task examines generation of indirect request interpretations, and the second the comprehension of irony. Intact contextual comprehension of indirect requests contrasts with marked difficulties in understanding irony. These results suggest that preserved pragmatics in ASD is limited to egocentric processing of context, which does not rely on assumptions about the speaker's mental states.

What Do You Have in Mind? Measures to Assess Mental State Reasoning in Neuropsychiatric Populations

Social interaction is closely associated with both functional capacity and well-being. Previous research has not only revealed evidence of social dysfunction in individuals with a wide range of psychiatric and neurological disorders but also generated an abundance of potential measures for assessing social cognition. This review explores the most popular measures used within neuropsychiatric populations to investigate the ability to recognize or reason about the mental states of others. Measures are also critically analyzed in terms of strengths and limitations to aid task selection in future clinical studies. The most frequently applied assessment tools use verbal, visual or audiovisual forms of presentation and assess recognition of mental states from facial features, self-rated empathy, the understanding of other's cognitive mental states such as beliefs and intentions, or the ability to combine knowledge of other's thoughts and emotions in order to understand subtle communications or socially inappropriate behavior. Key weaknesses of previous research include limited investigation of relationships with clinical symptoms, and underutilization of measures of everyday social functioning that offer a useful counterpart to traditional "lab" tasks. Future studies should aim to carefully select measures not only based on the range of skills to be assessed but also taking into account potential difficulties with interpretation and the need to gain insight into the application of social cognitive skills as well as ability per se. Some of the best measures include those with well-matched control trials (e.g., Yoni Task) or those that restrict the influence of verbal deficits (e.g., intentions comic strip task), elicit spontaneous mentalizing (e.g., Animations Task), and possess greater ecological validity (e.g., Movie for the Assessment of Social Cognition). Social cognitive research within psychiatric populations will be further enhanced through the development of more closely matched control tasks, and the exploration of relationships between task performance, medication, strategy use, and broader emotional and motor functions.

Abnormal alpha modulation in response to human eye gaze predicts inattention severity in children with ADHD

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In response to the human eye gaze, compared with TD children, ADHD children showed a decreased alpha lateralization.

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The attenuation of alpha modulation in ADHD children was mainly manifested in the left hemisphere.

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The left hemisphere alpha modulation predicted higher inattentive severity and lower behavioural accuracy in ADHD children.

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Classification analysis showed the left alpha modulation has a high capability to recognize ADHD from TD children.

Attention-deficit/hyperactivity disorder (ADHD) is characterized by problems in directing and sustaining attention. Recent behavioral studies indicated that children with ADHD are more likely to fail to show the orienting effect in response to human eye gaze. The present study aimed to identify the neurophysiological bases of attention deficits directed by social human eye gaze in children with ADHD, focusing on the relationship between alpha modulations and ADHD symptoms. The electroencephalography data were recorded from 8–13-year-old children (typically developing (TD): n = 24; ADHD: n = 21) while they performed a cued visuospatial covert attention task. The cues were designed as human eyes that might gaze to the left or right visual field. The results revealed that TD children showed a significant alpha lateralization in response to the gaze of human eyes, whereas children with ADHD showed an inverse pattern of alpha modulation in the left parieto-occipital area. Importantly, the abnormal alpha modulation in the left hemisphere predicted inattentive symptom severity and behavioral accuracy in children with ADHD. These results suggest that the dysfunction of alpha modulation in the left hemisphere in response to social cues might be a potential neurophysiologic marker of attention deficit in children with ADHD.

Variation in the Oxytocin Receptor Gene Is Associated With Social Cognition and ADHD

OBJECTIVE

Children with ADHD show substantial deficits in social cognitive abilities. Oxytocin, mediated through its specific receptor (OXTR), is involved in the regulation of social behavior and social cognition.

METHOD

The entire coding sequence of the human OXT and OXTR genes were sequenced to identify mutations and single nucleotide polymorphisms (SNPs) in 151 children with ADHD (ADHD-combined, n = 51; inattentive subtype, n = 50; ADHD-C plus conduct disorder [CD], n = 50; 11-18 years) and 100 healthy controls.

RESULTS

We examined the association of three detected SNPs of OXTR with social cognition deficits. A significant association was shown between the children with ADHD and children with CT/TT genotypes of rs4686302 (χ² = 3.695; p = .037). ADHD children with CT/TT genotype for the OXTR rs4686302 performed significantly lower on the facial emotion recognition task than those with CC genotype.

CONCLUSION

OXTR rs4686302 polymorphism was shown to be a genetic marker in social cognition deficits in ADHD children.

Executive Function and Theory of Mind in Children with ADHD: a Systematic Review

In developmental research, the relationship between Executive Function (EF) and Theory of Mind (ToM) has been extensively assessed, and EF has been considered a condition for ToM. However, few researchers have studied the relationship between EF and ToM in clinical populations, especially that of Attention Deficit Hyperactivity Disorder (ADHD), a neurodevelopmental disorder characterized by symptoms of inattention and motor hyperactivity/impulsivity, in which EF is largely impaired. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) model, 201 English and Spanish articles evaluating EF and ToM in ADHD were chosen. Fifteen papers met the inclusion criteria and were selected for further analysis. The first study dates from 2001. Most of the studies' designs are cross-sectional, include mostly male children, have a small sample size, and were conducted in European countries. Unlike tasks assessing EF, tasks assessing ToM were heterogeneous across studies. The EFs most correlated with ToM were inhibitory control, working memory, cognitive flexibility, and attention. Interest in studying the relationship between EF and ToM in ADHD is recent,but increasing based on new findings and tuning of ToM instruments. However, while an association between EF and ToM is indicated in ADHD, the degree of prediction and predictability of one over the other cannot yet be established because of the studies' heterogeneity.

Genome-wide association study of cognitive flexibility assessed by the Wisconsin Card Sorting Test

Cognitive flexibility is a critical component of executive function and is strongly influenced by genetic factors. We conducted a genome-wide association study of cognitive flexibility (as measured by perseverative errors on the Wisconsin Card Sorting Test) in two sets of African American (AA) and European American (EA) subjects (Yale-Penn-1: 1,411 AAs/949 EAs; Yale-Penn-2: 1,178 AAs/1,335 EAs). We examined the association of cognitive flexibility with genotyped or imputed SNPs across the genome. In AAs, two correlated common single nucleotide polymorphisms (SNPs) (rs7165213/rs35633795) in the downstream region of the noncoding gene LOC101927286 on chromosome 15 showed genome-wide significant (GWS) associations with cognitive flexibility (Yale-Penn-1: p = 6.0 × 10^-9 /1.3 × 10^-8 ; Yale-Penn-2: p = .029/.010; meta-analysis: p = 4.2 × 10^-7 /1.0 × 10^-7 ) in the same effect direction. In EAs, no GWS associations were observed. Enriched gene sets identified by Data-driven Expression-Prioritized Integration for Complex Traits (DEPICT) analysis of the top SNPs (p_{meta-analysis}  < 10^-5 ) included the signalosome and ubiquitin-specific peptidase 9, X-linked (USP9X) subnetwork in AAs, and abnormal frontal and occipital bone morphology in EAs. We also performed polygenic risk score (PRS) analysis to examine the genetic correlation of cognition-proxy phenotypes (general cognitive function, education attainment, childhood intelligence, and infant head circumference) and cognitive flexibility in EAs. The PRS derived from general cognitive function-associated SNPs was significantly associated with cognitive flexibility. Nongenetic factors (age, education, sex, and tobacco recency) also exerted significant effects on cognitive flexibility. Our study demonstrates that both genetic and nongenetic factors impact cognitive flexibility, and variants in genes involved in protein degradation and brain development may contribute to population variation in cognitive function.

The effect of methylphenidate treatment on suspiciousness in children with ADHD alone or comorbid with ODD

OBJECTIVE

To assess the level of the suspiciousness in children with attention deficit/hyperactivity disorder (ADHD) and comorbid oppositional defiant disorder (ODD) in comparison to ADHD alone and the response of suspiciousness symptoms to methylphenidate (MPH) treatment.

METHODS

In this open-label comparative study, children with DSM-IV-TR ADHD, aged 8-18 years, with (N = 30) or without (N = 30) ODD received MPH treatment for 12 weeks. The severity of ODD symptoms was assessed by the Kiddie-Schedule for Affective Disorders and Schizophrenia. The severity of ADHD symptoms was assessed by the ADHD-Rating-Scale-IV and suspiciousness was assessed at baseline and at endpoint by a scale designed especially for assessment of suspiciousness and named Suspiciousness Rating Scale (SRS).

RESULTS

Significant reductions in SRS scores were detected in both groups following MPH treatment (before and after: p = .0012 and p = .0273, respectively). Only in the ADHD/ODD group a significant correlation was found between the rate of improvement in ADHD, as assessed by the ADHD-RS, and the reduction in suspiciousness, as assessed by the SRS (Spearman r = 0.48, p =  .0066).

CONCLUSIONS

In addition to the beneficial effect of MPH treatment on ADHD and ODD symptoms it also diminishes suspiciousness. However, due to the small sample size further studies are needed to confirm the present results.

A role for epistemic trust in speech-language pathology: A tutorial paper

This paper provides an introduction to epistemic trust for speech-language pathologists (SLPs). 'Epistemic trust' describes a specific form of trust that an individual places in others when learning about the world, particularly the social world. To date, the relevance of epistemic trust to SLP clinical practice has received little theoretical or empirical attention. The aim of this paper is to define epistemic trust and explain its relationship with parent-child attachment and mentalization which have, in turn, been linked with language development and use. Suggestions are made for ways in which SLPs may encourage epistemic trust in clients, emphasizing the need to establish strong therapeutic alliances. The authors conclude that epistemic trust is an important consideration for SLPs and that further research exploring the relationship between epistemic trust and language skills is needed to better understand the interplay of these variables and inform clinical practice.

Genetic contribution to 'theory of mind' in adolescence

Difficulties in 'theory of mind' (the ability to attribute mental states to oneself or others, and to make predictions about another's behaviour based on these attributions) have been observed in several psychiatric conditions. We investigate the genetic architecture of theory of mind in 4,577 13-year-olds who completed the Emotional Triangles Task (Triangles Task), a first-order test of theory of mind. We observe a small but significant female-advantage on the Triangles Task (Cohen's d = 0.19, P < 0.01), in keeping with previous work using other tests of theory of mind. Genome-wide association analyses did not identify any significant loci, and SNP heritability was non-significant. Polygenic scores for six psychiatric conditions (ADHD, anorexia, autism, bipolar disorder, depression, and schizophrenia), and empathy were not associated with scores on the Triangles Task. However, polygenic scores of cognitive aptitude, and cognitive empathy, a term synonymous with theory of mind and measured using the "Reading the Mind in the Eyes" Test, were significantly associated with scores on the Triangles Task at multiple P-value thresholds, suggesting shared genetics between different measures of theory of mind and cognition.

Complexity Analysis of Resting-State fMRI in Adult Patients with Attention Deficit Hyperactivity Disorder: Brain Entropy

Objective

Complexity analysis of functional brain structure data represents a new multidisciplinary approach to examining complex, living structures. I aimed to construct a connectivity map of visual brain activities using resting-state functional magnetic resonance imaging (fMRI) data and to characterize the level of complexity of functional brain activity using these connectivity data.

Methods

A total of 25 healthy controls and 20 patients with attention deficit hyperactivity disorder (ADHD) participated. fMRI preprocessing analysis was performed that included head motion correction, temporal filtering, and spatial smoothing process. Brain entropy (BEN) was calculated using the Shannon entropy equation.

Results

My findings demonstrated that patients exhibited reduced brain complexity in visual brain areas compared to controls. The mean entropy value of the ADHD group was 0.56 ± 0.14, compared to 0.64 ± 0.11 in the control group.

Conclusion

My study adds an important novel result to the growing literature pertaining to abnormal visual processing in ADHD that my ADHD patients had lower BEN values, indicating more-regular functional brain structure and abnormal visual information processing.

Specificity of executive function and theory of mind performance in relation to attention-deficit/hyperactivity symptoms in autism spectrum disorders

Background

Individuals with autism spectrum disorder (ASD) frequently demonstrate symptoms of attention-deficit/hyperactivity disorder (ADHD). Previous findings in children with ASD have suggested that these symptoms are associated with an impairment in executive function (EF) abilities. However, studies rarely considered this association within a single framework that controls for other related factors such as Theory of Mind (ToM) abilities and ASD symptoms.

Methods

We used structural equation modeling to explore the relations among EF, ToM, and symptoms of ASD and ADHD, using data from a population-based sample of 100 adolescents with ASD and full-scale IQ ≥ 50 (the Special Needs and Autism Project (SNAP) cohort). The study used a multi-measure and multi-informant approach, where performance of inhibition, planning, switching, and working memory tasks indexed EF and performance on tasks involving mentalizing indexed ToM. Measures of ASD and ADHD symptoms included parent and teacher reports and direct observation of the children. Shared source of symptom reporting was accounted for with a parental rating latent factor indexed by symptom measures reported by parents.

Results

Impairments in EF abilities were specifically associated with ADHD symptoms while impaired ToM was specifically associated with ASD symptoms, when accounting for the associations of each cognitive domain with the other factors. ASD and ADHD symptom latent factors were also correlated, but this association became nonsignificant once the shared source of reporting from parents was accounted for and within a model that also controlled for the correlated pathway between EF and ToM factors. The specific relations between the cognitive domains and behavioral symptoms remained even after controlling for IQ.

Conclusions

In this ASD sample, symptoms of ADHD and ASD are underpinned by separate cognitive domains. The association between EF and ToM impairments is a likely partial explanation for the co-occurrence of ADHD symptoms in ASD, but the role of shared reporting effects is also important and supports the inclusion of independent informants and objective measures in future research.

The Association between Sleep and Theory of Mind in School Aged Children with ADHD

Theory of Mind (ToM) is defined as the ability to infer a range of internal mental states of others, including beliefs, intentions, desires, and emotions. These abilities are associated with children’s ability to socialize effectively with peers. ToM impairments are associated with peer rejection and psychiatric disorders such as Attention-Deficit/Hyperactivity Disorder (ADHD). Previous studies have found poor sleep negatively impacts executive functioning (EF) and emotional information processing, which are essential for the effective use of ToM. Youth with ADHD have EF deficits and sleep problems. However, the relationship between sleep, executive functioning, and ToM in children with ADHD has not been studied. In this review, we propose that the poor social and interpersonal skills characterizing individuals with ADHD could be explained by the impact of poor sleep on the emotional and cognitive mechanisms underlying ToM.

Attentional control of emotional interference in children with ADHD and typically developing children: An emotional N-back study

Emotional interference control refers to the ability to remain focused on goal-oriented processes when confronted with disrupting but irrelevant emotional stimuli, a process that may be impaired in children and adults with attention deficit/hyperactivity disorder (ADHD). However, emotional interference levels are known to be associated with trait anxiety, and patients with ADHD often display elevated levels of trait anxiety, such as these may have confounded previous findings of decreased emotional interference control in this population. In the present study, male and female 8-13 years old (mean =11.0 years) children with ADHD (n=33) and typically developing (TD) children (n=24) performed a visual emotional working memory (n-back) task with 2 memory loads and three different background pictures (neutral/positive/negative), and trait anxiety measures were obtained. Children with ADHD performed less well, and displayed increased emotional interference in the presence of aversive distractors when compared with TD children. Contrary to our expectations, trait anxiety did not mediate the association between diagnostic group membership and the degree of emotional interference control; however, co-morbid ODD was associated with decreased levels of emotional interference in ADHD. Future research should aim at characterizing the mechanisms subtending decreased emotional interference control in the ADHD population.

Social Cognition in Children with High-Functioning Autism Spectrum Disorder and Attention-Deficit/Hyperactivity Disorder. Associations with Executive Functions

Autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) are neurodevelopmental disorders characterized by social impairments. The first objective of this study was to analyze social cognition deficits of children with ADHD, high-functioning ASD (HFASD), and typical development (TD) in their performance on explicit and applied measures of theory of mind (ToM). The second objective was to investigate the relationships between executive functions and social cognition in HFASD and ADHD. One hundred and twenty-six 7- to 11-year old children, 52 with HFASD, 35 with ADHD, and 39 with TD, performed the NEPSY-II social perception subtests. Parents estimated their children's ToM skills using the Theory of Mind Inventory (ToMI). Teacher-reported data from the Behavior Rating Inventory of Executive Function (BRIEF) were also obtained. The HFASD and ADHD groups showed worse performance on the verbal ToM task than the TD group, and only the performance of the HFASD group was significantly lower than the TD group on the contextual ToM task. Parents also estimated that the HFASD group had more difficulties on the applied ToM than the ADHD and TD groups. Furthermore, there is a different executive function-theory of mind link in the HFASD and ADHD groups: behavioral regulation processes such as inhibition and emotional control are more associated with social cognition in children with ADHD, whereas metacognitive processes such as initiation and planning have a strong association with social cognition in children with HFASD. These findings have implications for understanding social perception deficits in neurodevelopmental disorders, highlighting the need for early intervention.

The Possible Effect of Methylphenidate Treatment on Empathy in Children Diagnosed with Attention-Deficit/Hyperactivity Disorder, Both With and Without Comorbid Oppositional Defiant Disorder

OBJECTIVE

To assess the Empathizing Quotient (EQ) of patients diagnosed with attention-deficit/hyperactivity disorder (ADHD) only or comorbid with oppositional defiant disorder (ODD) and compare the two groups' responses to methylphenidate (MPH) treatment.

METHODS

Fifty-two children (8-18 years) diagnosed with ADHD, 26 of whom were also diagnosed with comorbid ODD (ADHD/ODD), were treated with MPH for 12 weeks. The level of EQ was assessed with the Children's version of the Empathizing Quotient (EQ-C) and the severity of ADHD symptoms with the ADHD Rating Scale (ADHD-RS). Assessments were done at baseline and at end point.

RESULTS

A significant increase in EQ scores was obtained in both groups following MPH treatment (p = 0.003 for ADHD/ODD; p = 0.002 for ADHD). Significant correlation was found in the ADHD group between the changes in ADHD-RS and those in EQ, following MPH treatment (p = 0.015), but not in the ADHD/ODD group (p = 0.48).

CONCLUSIONS

A correlation exists between MPH-related improvement in ADHD symptoms and between more empathy in children with ADHD not comorbid with ODD.

Neuropsychological and neurophysiological benefits from white noise in children with and without ADHD

Background

Optimal stimulation theory and moderate brain arousal (MBA) model hypothesize that extra-task stimulation (e.g. white noise) could improve cognitive functions of children with attention-deficit/hyperactivity disorder (ADHD). We investigate benefits of white noise on attention and inhibition in children with and without ADHD (7–12 years old), both at behavioral and at neurophysiological levels.

Methods

Thirty children with and without ADHD performed a visual cued Go/Nogo task in two conditions (white noise or no-noise exposure), in which behavioral and P300 (mean amplitudes) data were analyzed. Spontaneous eye-blink rates were also recorded and participants went through neuropsychological assessment. Two separate analyses were conducted with each child separately assigned into two groups (1) ADHD or typically developing children (TDC), and (2) noise beneficiaries or non-beneficiaries according to the observed performance during the experiment. This latest categorization, based on a new index we called “Noise Benefits Index” (NBI), was proposed to determine a neuropsychological profile positively sensitive to noise.

Results

Noise exposure reduced omission rate in children with ADHD, who were no longer different from TDC. Eye-blink rate was higher in children with ADHD but was not modulated by white noise. NBI indicated a significant relationship between ADHD and noise benefit. Strong correlations were observed between noise benefit and neuropsychological weaknesses in vigilance and inhibition. Participants who benefited from noise had an increased Go P300 in the noise condition.

Conclusion

The improvement of children with ADHD with white noise supports both optimal stimulation theory and MBA model. However, eye-blink rate results question the dopaminergic hypothesis in the latter. The NBI evidenced a profile positively sensitive to noise, related with ADHD, and associated with weaker cognitive control.

Theory of Mind in Depressive Disorders: A Review of the Literature

BACKGROUND

Theory of mind (ToM) is the ability to infer the mental states of others in order to understand and predict their behaviour. This ability is thought to be essential to social functioning and interpersonal relationships. As major depression is characterized by considerable social and interpersonal difficulties, exploration of the quality of ToM functioning can be particularly relevant in this and in related disorders. We aim to review the current state of research on ToM in depressive disorders in order to find out the extent to which ToM impairment is associated with these illnesses.

METHODS

An internet database search was carried out to collect all publications on the subject.

RESULTS

A total of 32 publications in English met our inclusion criteria: (a) 17 studies on ToM in major depression, (b) 4 studies on ToM in psychotic depression, (c) 3 studies on ToM in dysphoria or mild depression, (d) 4 studies on ToM in euthymic major depression, (e) 2 studies on ToM in chronic versus episodic depression, and (f) 2 studies on ToM in another psychiatric disorder with comorbid major depression.

CONCLUSIONS

Despite an increased interest in the research of the topic in recent years, no firm conclusions can be drawn, as the reviewed articles present some conflicting results. Acutely depressed patients have been found to be impaired on tasks involving both ToM social-perceptual and social-cognitive components. On the other hand, a number of studies have not reported significant between-group differences between depressed patients and healthy controls or have found minimal differences. Further research is needed in order to confirm and extend these results.

Impact of Acute Sleep Deprivation on Sarcasm Detection

There is growing evidence that sleep plays a pivotal role on health, cognition and emotional regulation. However, the interplay between sleep and social cognition remains an uncharted research area. In particular, little is known about the impact of sleep deprivation on sarcasm detection, an ability which, once altered, may hamper everyday social interactions. The aim of this study is to determine whether sleep-deprived participants are as able as sleep-rested participants to adopt another perspective in gauging sarcastic statements. At 9am, after a whole night of sleep (n = 15) or a sleep deprivation night (n = 15), participants had to read the description of an event happening to a group of friends. An ambiguous voicemail message left by one of the friends on another's phone was then presented, and participants had to decide whether the recipient would perceive the message as sincere or as sarcastic. Messages were uttered with a neutral intonation and were either: (1) sarcastic from both the participant’s and the addressee’s perspectives (i.e. both had access to the relevant background knowledge to gauge the message as sarcastic), (2) sarcastic from the participant’s but not from the addressee’s perspective (i.e. the addressee lacked context knowledge to detect sarcasm) or (3) sincere. A fourth category consisted in messages sarcastic from both the participant’s and from the addressee’s perspective, uttered with a sarcastic tone. Although sleep-deprived participants were as accurate as sleep-rested participants in interpreting the voice message, they were also slower. Blunted reaction time was not fully explained by generalized cognitive slowing after sleep deprivation; rather, it could reflect a compensatory mechanism supporting normative accuracy level in sarcasm understanding. Introducing prosodic cues compensated for increased processing difficulties in sarcasm detection after sleep deprivation. Our findings support the hypothesis that sleep deprivation might damage the flow of social interactions by slowing perspective-taking processes.