Executive functioning in children with autism and Tourette syndrome

The main aims of this study were to investigate if children with high-functioning autism (HFA) and children with Tourette syndrome (TS) can be differentiated in their executive functioning (EF) profile compared to normal controls (NCs) and compared to each other and to investigate whether children with HFA or children with TS and a comorbid group of children with both disorders are distinct conditions in terms of EF, Four groups of children participated in this study: HFA, TS, comorbid HFA + TS, and a NC group. All children were in the age range of 6 to 13 years. The groups were compared on five major domains of EF: inhibition, visual working memory, planning, cognitive flexibility, and verbal fluency. Children with HFA scored lower than NC children on all the EFs measured. Children with TS and NC children showed the same EF profile. The HFA group scored lower than the TS group for inhibition of a prepotent response and cognitive flexibility. Children with HFA performed poorer than children with comorbid HFA + TS on all functions, with the exception of inhibiting an ongoing response, interference control, and verbal fluency. Children with TS and children with comorbid HFA + TS could not be differentiated from one another in terms of EF. This study indicates that EF deficits are highly characteristic of children with HFA in comparison to children with TS and NC. The results suggest that for the comparison between HFA and TS groups, it is important to take into account comorbidity. A reevaluation of the EF hypothesis in children with TS is suggested.     

Executive function,memory, and learning in Tourette's syndrome

Young people with Tourette's syndrome (TS) alone, TS plus attention-deficit/hyperactivity disorder (+ADHD), or TS plus obsessive-compulsive disorder (+OCD) were compared with a healthy control group on a set of measures of executive functioning, memory, and learning. The TS-alone group was impaired on one executive measure involving inhibition and strategy generation but did not differ significantly from the healthy control group on other measures. The TS+ADHD group showed impairment on several executive measures. There was no evidence of impairment in implicit aspects of memory and learning for any of the TS groups. The findings are discussed in terms of the frontostriatal hypothesis of TS and the contribution of comorbid symptomatology.     

Increased prevalence of ADHD in Turner syndrome with no evidence of imprinting effects

BACKGROUND: Turner syndrome (TS) results from the loss of part or all of one X chromosome in females. It can result in short stature, various dysmorphic findings, and difficulties with psychosocial adjustment. Girls with TS have previously been found to exhibit increased levels of hyperactivity and inattention. However, no studies have assessed whether individuals with TS meet strict (DSM-IV) criteria for attention-deficit/hyperactivity disorder (ADHD). OBJECTIVE: We looked at the prevalence of ADHD in girls with TS and evaluated the contribution of imprinting on cognitive performance (IQ) and ADHD. METHODS: We tested 50 girls with TS for ADHD, IQ, academic performance, and parental origin of the X chromosome. RESULTS: We report an 18-fold increase in the prevalence of ADHD in girls with TS (24%) compared with girls in the general population (1.3%) (p < .01) and a 4.8 fold increase when compared with boys and girls in the general population (5%) (p < .05). In contrast to previous reports, our molecular studies in females with 45,X also showed no association between IQ scores and the parental origin of the intact X chromosome. CONCLUSIONS: We find an increased prevalence of ADHD in girls with TS but no evidence for imprinting effects for cognitive performance.     

Tourette's and comorbid syndromes: obsessive compulsive and attention deficit hyperactivity disorder. A common etiology?

Tourette's syndrome (TS), a neuropsychiatric movement disorder that manifests itself in childhood, is often associated with comorbid symptomatology, such as obsessions, compulsions, hyperactivity, distractibility, and impulsivity. Epidemiological studies suggest that a substantial number of TS patients develop clinical levels of obsessive-compulsive disorder (OCD) and/or attention deficit hyperactivity disorder (ADHD). This review aims to provide an integrated account of the three disorders in terms of their comorbidity. Neuroimaging studies suggest that all three disorders involve neuropathology of the basal-ganglia thalamocortical (BGTC) pathways: TS in the sensorimotor and limbic BGTC circuits; OCD in the prefrontal and limbic BGTC pathways; and ADHD in the sensorimotor, orbitofrontal, and limbic BGTC circuits. The pattern of comorbidity and other evidence indicates that the TS gene(s) may be responsible for a spectrum of disorders, including OCD and ADHD, but also that the disorders OCD and ADHD can exist in their own right with their own etiologies.     

Attention-deficit/hyperactivity disorder, Tourette's syndrome, and restless legs syndrome: the iron hypothesis

Preliminary but increasing evidence suggests that attention-deficit/hyperactivity disorder (ADHD), Tourette's syndrome (TS), and restless legs syndrome (RLS) may be comorbid. In the present article, we hypothesize that ADHD, TS, and RLS may be part of a spectrum, and that iron deficiency contributes to the pathophysiology underlying this spectrum. Iron deficiency might lead to ADHD, RLS and TS symptoms via its impact on the metabolism of dopamine and other catecholamines, which have been involved into the pathophysiology of ADHD, TS, and RLS. We speculate that the catecholaminergic systems are differently impacted in each of the three disorders, contributing to a different specific phenotypic expression of iron deficiency. MRI studies assessing brain iron levels in ADHD, TS, and childhood RLS, as well as genetic studies on the specific molecular pathways involved in iron deficiency, are greatly needed to confirm the iron hypothesis underlying ADHD, TS, and RLS. This body of research may set the basis for controlled trials assessing the effectiveness and tolerability, as well as the most appropriate dose, duration and type (oral vs. intravenous) of iron supplementation. In conclusion, the iron hypothesis may help us progress in the understanding of pathophysiological links between ADHD, RLS, and TS, suggesting that iron supplementation might be effective for all these three impairing conditions.     

Neuropsychological correlates of methylphenidate treatment in adult ADHD with and without depression.

The purpose of this study was to characterize the neuropsychological profiles of adult patients with attention deficit hyperactivity disorder (ADHD) alone and ADHD with active comorbid depression, and to evaluate changes in the neuropsychological profile in these two groups following a trial of methylphenidate. Forty patients with ADHD were classified into two groups based on their affective status resulting in a group of 21 patients with ADHD alone and 19 patients with ADHD and active comorbid symptoms of depression (ADHD-D). All subjects received a comprehensive neuropsychological evaluation including measures of cognitive, motor and affective functioning before and after treatment. Fifteen normal controls were also assessed at a yoked time interval. At baseline, both patient groups showed impairment in verbal memory, motor and processing speed, visual scanning, and auditory and visual distractibility. Following treatment, both patient groups showed improvement across all neuropsychological measures while controls remained relatively stable over time. Improvement in neuropsychological test performance was not related to gender, affective status or referral source. Patients with active comorbid symptoms of depression show a similar neuropsychological profile and appear equally likely to benefit from methylphenidate intervention as patients with ADHD alone.     

Depressive symptomatology in young people with Gilles de la Tourette Syndrome-- a comparison of self-report scales

BACKGROUND: Few studies have examined depressive symptomatology in children and adolescents with Tourette Syndrome (TS) using standardised measures and none have compared different self-report scales in the context of TS. METHODS: Seventy-two consecutive young people attending a TS clinic were evaluated using standardised rating scales for TS and associated behaviours, severity and psychopathology. All the patients completed the Birleson Depression Self Report Scale (BDSRS) and the Children's Depression Inventory (CDI). RESULTS: A strong correlation was noted between BDSRS and CDI. Depression scores were also noted to correlate with Obsessive Compulsive Behaviours (OCB) and Attention Deficit Hyperactivity Disorder (ADHD). Other correlates of depressive symptomatology included current severity of TS as indicated by Yale Global Tic Severity Rating Scale (YGTSS) and the lifetime cumulative severity as evidenced by scores on the Diagnostic Confidence Index (DCI). LIMITATIONS: The study was undertaken in a tertiary referral specialized clinic for TS thus limiting the generalizability of the findings, and the study did not include any control subjects. CONCLUSIONS: The results provide support for the need and usefulness of both BDSRS and CDI as screening tools for depressive symptoms in children and adolescents with TS. Furthermore, the findings suggest the possibility of a complex inter-relationship between TS severity, comorbid OCB and ADHD as well as the occurrence of depression.     

Tourette's syndrome (TS): cognitive performance in adults with uncomplicated TS

Tourette's syndrome (TS) is a neurodevelopmental disorder associated with frontostriatal dysfunction. The extent of any cognitive impairment associated with uncomplicated TS is unclear, as comorbid psychiatric symptomatology is thought to contribute to cognitive deficits. Previous studies have found evidence of mild performance deficits, most commonly on tasks that involve inhibitory processes. The present study evaluated this in carefully screened adult participants with TS. The findings showed the TS group to perform more poorly on one test involving behavioral inhibition (sentence completion), but did not provide strong support for an interpretation based solely on inhibitory deficits, and there was no evidence of impairment on another behavioral inhibition task (flanker test). There were also no differences between the groups on tasks involving working memory (n-back), task switching, or object alternation learning. The findings provide further evidence that uncomplicated TS is associated with only mild, circumscribed impairment. The nature of any impairment is discussed.     

Relationship between allergic rhinitis, disturbed cognitive functions and psychological well-being

BACKGROUND: Symptomatic allergic rhinitis reduces quality of life as a result of the symptoms experienced and possibly as a result of impaired psychological well-being and cognitive functioning. Few investigations have measured cognitive functions objectively and it remains uncertain whether allergic rhinitis leads to an objective reduction in cognitive functions. OBJECTIVE: To evaluate the relationship between symptomatic allergic rhinitis, cognitive functions and psychological well-being. Differences between subjective and objective cognitive impairments were evaluated. METHODS: The cognitive functions (working memory, memory retrieval, speed of information processing and flexibility of information processing) and psychological well-being of 26 patients with symptomatic allergic rhinitis and 36 healthy controls matched for intelligence, education, age and sex were compared. The influence of education, intelligence, sex and age was considered. RESULTS: Overall, psychological well-being was significantly impaired in the patient group, as shown by higher scores in feelings of insufficiency, complaints of somatization, sleep disturbances and depressive feelings, whereas cognitive function was not. CONCLUSIONS: Allergic rhinitis was related to significantly impaired psychological well-being and to perceived impaired cognitive functioning. However, no significant objective impairment of cognitive functioning was found. Allergic patients may temporarily put more effort into sustaining performance, resulting in earlier exhaustion, which is not noticed during assessment but which impairs psychological well-being.     

Attention-deficit hyperactivity disorder symptoms and quality of life in female patients with fibromyalgia

Background/aim The present study aimed to determine the association between attention-deficit hyperactivity disorder (ADHD) symptoms severity, fibromyalgia (FM) severity, and QoL.Materials and methodsWhile the FM group consisted of 113 (74%) patients, the control group consisted of 40 (26%) individuals. FM symptom severity, ADHD symptom severity, and QoL were evaluated using the fibromyalgia impact questionnaire (FIQ), adult ADHD self-report scale (ASRS), and World Health Organization quality of life scale-brief version (WHOQOL-BREF), respectively. ResultsIt was found that the FM group had significantly higher scores on the ASRS than the control group (p < 0.05). There was a significant difference in FIQ scores and three WHOQOL-BREF domain scores between the FM alone and comorbid FM/high probability of ADHD groups (p < 0.05). We found a negative correlation between ASRS total scores and all other scale scores (except for the social relationships domain score of the WHOQOL-BREF) and a positive correlation between ASRS total scores and FIQ scores in FM patients. ADHD scores would mediate the relationship between depression severity and QoL.ConclusionsOur findings indicated that the presence of ADHD symptoms was related to greater FM symptom severity and poorer QoL. Also, ADHD scores would mediate the relationship between depression severity and QoL.     

Course and outcome of bipolar spectrum disorder in children and adolescents: a review of the existing literature

The longitudinal course of children and adolescents with bipolar disorder (BP) is manifested by frequent changes in symptom polarity with a fluctuating course showing a dimensional continuum of bipolar symptom severity from subsyndromal to mood syndromes meeting full Diagnostic and Statistical Manual of Mental Disorders criteria. These rapid fluctuations in mood appear to be more accentuated than in adults with BP, and combined with the high rate of comorbid disorders and the child's cognitive and emotional developmental stage, may explain the difficulties encountered diagnosing and treating BP youth. Children and adolescents with early-onset, low socioeconomic status, subsyndromal mood symptoms, long duration of illness, rapid mood fluctuation, mixed presentations, psychosis, comorbid disorders, and family psychopathology appear to have worse longitudinal outcome. BP in children and adolescents is associated with high rates of hospitalizations, psychosis, suicidal behaviors, substance abuse, family and legal problems, as well as poor psychosocial functioning. These factors, in addition to the enduring and rapid changeability of symptoms of this illness from very early in life, and at crucial stages in their lives, deprive BP children of the opportunity for normal psychosocial development. Thus, early recognition and treatment of BP in children and adolescents is of utmost importance.     

首发精神分裂症患者认知功能与精神症状及疗效的关系

目的：探讨首发精神分裂症患者的认知和功能与精神症状及疗效的关系。方法：对１６４例首发精神分裂症患者随机给予氯丙嗪或氯氮平治疗;于治疗前分别作韦氏成人智力量表、韦氏记忆量表、铁槽铁钉测验、手指敲击测试、动作功能测验、手功能协调测验、连线测验Ａ和Ｂ、威斯康星卡片分类测验（ＷＣＳＴ）及词语流畅性测验１１项神经心理测查各一次,并作ＢＰＲＳ、ＳＡＮＳ、功能总体评定量表（ＧＡＦ）一次;治疗１２周末再评定１次上     

Cognitive predictors of sequential motor impairments in children with dyslexia and/or attention deficit/hyperactivity disorder

This study examined cognitive predictors of sequential motor skills in 215 children with dyslexia and/or attention deficit/hyperactivity disorder (ADHD). Visual working memory and math fluency abilities contributed significantly to performance of sequential motor abilities in children with dyslexia (N = 67), ADHD (N = 66) and those with a comorbid diagnosis (N = 82), generally without differentiation between groups. In addition, primary diagnostic features of each disorder, such as reading and inattention, did not contribute to the variance in motor skill performance of these children. The results support a unifying framework of motor impairment in children with neurodevelopmental disorders such as dyslexia and ADHD.     

Symptoms of attention-deficit/hyperactivity disorder in adults with restless legs syndrome

OBJECTIVE: To determine the occurrence of symptoms of attention-deficit/hyperactivity disorder (ADHD) in adults with restless legs syndrome (RLS), normal controls, and controls with insomnia. SETTING: University-based hospital. METHODS: The occurrence and severity of current ADHD symptoms were determined in a prospective study of sequential adult patients with RLS (n = 62) or insomnia (n = 32) and adult controls (n = 77) using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) ADHD criteria, the Brown Attention-Deficit Disorder (ADD) Scale for adults, and a structured psychological interview. RLS severity was assessed using the International RLS Study Group Rating Scale (IRLS). RESULTS: Only 1 experimental subject had previously been diagnosed with ADHD. More RLS patients (26%) than insomnia patients (6%) or controls (5%) had ADHD symptoms using age-adjusted total DSM-IV ADHD scores (P < .01). The mean Brown ADD score was greater in RLS patients (37 +/- 28) than in patients with insomnia (24 +/- 18) or controls (21 +/- 18) (P < .01). The RLS symptom severity (0-40 scale) was greater in RLS patients with ADD symptoms (26 +/- 9) than in those without ADD (21 +/- 10) (P < .04). Of the subjects with a Brown ADD score > 40, all reported ADD symptoms in 2 settings, and the majority had had ADHD symptoms since childhood. For subjects with a Brown ADD score > 40, there were no differences between the RLS, insomnia control, and normal control groups in quality of life or the level of anxiety or depression. CONCLUSIONS: ADHD symptoms are more common in RLS patients than in patients with insomnia or controls. RLS leg discomfort or poor quality of sleep may theoretically lead to hyperactivity and lack of concentration. Alternatively, RLS and ADHD may be part of a single symptom complex, and dopaminergic deficiency may play a role in both disorders.     

Relationships between neuropsychological measures of executive function and behavioral measures of ADHD symptoms and comorbid behavior.

OBJECTIVE: The aim of this study was to examine the relationship between executive functions (EFs), as measured by neuropsychological tests, and symptoms of attention deficit hyperactivity disorder (ADHD) and comorbid behavior, as rated by parents and teachers. As intelligence and language ability are important covariates they were also assessed. METHOD: The sample consisted of 43 children aged 7-11 years who were referred for neuropsychological assessment at a tertiary clinical facility. Most of the children had the diagnosis of ADHD combined or inattentive type. Different aspects of EFs were assessed. RESULTS: EFs were not significantly related to symptoms of ADHD, but only to comorbid symptoms of depression and autistic symptomatology. Language ability rather than EFs best predicted teacher ratings of inattention. CONCLUSIONS: The results of the study do not support the EF theory of ADHD. The importance of screening for comorbid language disorders in children referred for ADHD is emphasized.     

Language-based cognitive functioning in parents of offspring with ADHD comorbid for Tourette syndrome or learning disabilities

The parents of children diagnosed with attention deficit hyperactivity disorder (ADHD) were examined for characteristics symptomatic of 2 comorbidities (Co) within their offspring with ADHD: Tourette syndrome (TS) and language-based learning disabilities (LD). A 2 ×2 multivariate analysis of variance design was used; the parents were divided according to whether the offspring with ADHD had TS (Co-TS) or not (No Co-TS) and whether offspring had LD (Co-LD) or not (No Co-LD). Parents (86 mothers and 70 fathers) were administered the short form of the Wechsler Adult Intelligence Scale-Revised (WAIS-R; Wechsler, 1981), subtests of the Woodcock-Johnson Cognitive and Achievement Batteries (Woodcock & Johnson, 1989), and word fluency (semantic and letter; Benton & Hamsher, 1989; Wiig & Semel, 1987). The fathers of offspring with Co-TS were more likely to be diagnosed with LD and had lower WAIS-R Vocabulary, Arithmetic, and Picture Arrangement scores. In addition, when the WAIS-R full scale IQ was used as a covariate, these fathers had lower Woodcock-Johnson Oral Vocabulary, Spelling, and Reading scores (as measured by Letter-Word Identification). The mothers of children with Co-TS had lower WAIS-R Vocabulary scores. Parents of the children with No Co-TS showed a higher proportion of error patterns on the word fluency tasks involving repetitions and rule breaks. The findings show that it was the parents of the children with Co-TS, not the parents of the children with Co-LD, who showed language-based learning problems. In separate discriminant analyses for the fathers and mothers, when the aforementioned significant parental measures were used as predictors, 81% of offspring with Co-TS were correctly classified as having a diagnosis of TS, solely on the basis of characteristics in their parents.     

Evidence that specific executive functions predict symptom variance among schizophrenia patients with a predominantly negative symptom profile

Introduction. Although deficits in executive functioning in schizophrenia have been consistently reported, their precise relationship to symptomatology remains unclear. Recent approaches to executive functioning in nonschizophrenia studies have aimed to “fractionate” the individual cognitive processes involved. In this study, we hypothesised that if these processes are fractionable, then particular symptom syndromes may be selectively related to executive deficits. In particular, it was hoped that this approach could clarify whether negative and positive symptoms of schizophrenia are differentially related to particular aspects of executive/attentional functions. Methods. A total of 32 patients with schizophrenia and 16 matched controls were assessed on a series of tasks designed to tap the theoretically derived executive functions of Inhibition, Shifting set, Working memory, and Sustained attention. Results. Negative symptoms were significantly predicted by performance on an “Inhibition” task (Stroop), and not by performance on any other task. Furthermore, for a subgroup of patients with predominantly negative symptoms variance in positive symptoms was only significantly predicted by performance on a set-shifting task (Visual Elevator), and not by performance on other tasks, including inhibition. Conclusions. Our results support the contention that negative symptoms can, at least partly, be conceived of as cognitive behaviours expressing specific executive deficits. Specifically, we discuss the possibility that negative symptoms may, in part, express a failure in response monitoring. We further suggest that the disordered metacognition resulting in positive symptoms may be mediated by cognitive flexibility in patients with a predominantly negative symptom profile.     

Social reasoning in Tourette syndrome

Introduction. Tourette syndrome (TS) is thought to be associated with striatal dysfunction. Changes within frontostriatal pathways in TS could lead to changes in abilities reliant on the frontal cortex. Such abilities include executive functions and aspects of social reasoning.

Methods. This study aimed to investigate executive functioning and Theory of Mind (ToM; the ability to reason about mental states, e.g., beliefs and emotions), in 18 patients with TS and 20 controls. A range of tasks involving ToM were used. These required participants to make judgements about mental states based on pictures of whole faces or the eyes alone, reason about humour in cartoons that featured sarcasm, irony or “slapstick” style humour, and make economic decisions. The executive measures assessed inhibition and verbal fluency.

Results. Patients with TS exhibited significantly poorer performance than controls on all four tasks involving ToM, even when patients with comorbid obsessive-compulsive disorder were excluded. These difficulties were despite no inhibitory deficits. Patients with TS exhibited impairment on the verbal fluency task but their performance on executive and ToM tasks was not related.

Conclusions. We propose that TS is associated with changes in ToM. The observed deficits could reflect dysfunction in frontostriatal pathways involving ventromedial prefrontal cortex.     

共患其他精神障碍的Tourette’s综合征患儿的父母养育方式

目的:初步探讨Tourette’s综合征(TS)患儿有无共患其他精神障碍与其父母养育方式特点的关系,为探索父母养育方式在TS发病机制和治疗中的意义提供线索。方法:采用个体匹配对照研究设计,以87例7～17岁共患其他精神障碍(注意缺陷多动障碍24例,强迫障碍33例,抑郁状态21例,分离和转换障碍9例)的TS患儿(TS共病组)、87例无共患其他精神障碍TS患儿(TS无共病组)以及87例正常少年对照(健康对照组)为研究对象。采用美国精神障碍诊断与统计手册第4版(DSM-Ⅳ)标准做出相应诊断。全部被试均完成一般情况调查表及父母养育方式问卷中文版(EMBU)的评估。结果:TS共病组、TS无共病组的EM-BU父亲惩罚严厉、拒绝否认、过度保护因子分均高于健康对照组,且TS共病组父亲惩罚严厉因子分高于TS无共病组;TS共病组的母亲的惩罚严厉、拒绝否认、过度保护因子分高于TS无共病组、健康对照组(均P<0.01)。回归分析结果显示父母惩罚严厉、过分干涉、拒绝否认、过度保护因子分与"是TS共病患儿"呈正相关(β=1.8～5.3,均P≤0.01)。结论:TS患儿的父母养育方式主要表现为父母对子女拒绝接纳、否定及过度保护,父母养育方式中的惩罚严厉、拒绝否认、过度保护可能与Tourette’s综合征共患其他精神障碍及发病存在更为密切的联系,值得今后研究重点关注。     

Heterogeneity in cognitive functioning among patients with bipolar disorder

BACKGROUND: Nowadays it is not clear if in bipolar disorders (BD) cognitive impairments are heterogeneous and if so which are the variables that determine it. METHODS: Fifty patients with BD and thirty healthy controls were clinically evaluated including measures of obstetric complications history. All subjects completed an extensive neuropsychological battery selected to asses premorbid IQ and different cognitive domains. RESULTS: Compared with standardized norms, 38% of patients had none cognitive domain affected, while 40% had 1 to 2, and 22% had 3 to 5. Patients with cognitive functioning within normal limits had higher psychosocial functioning and premorbid IQ, and lower history of obstetric complications. LIMITATIONS: The small sample size could limit the generalizability of the results; since these data should be taken as preliminaries. CONCLUSIONS: The extension and severity of cognitive impairments may be heterogeneous in patients with BD, and it might contribute to explain the variability in functional outcome. Bipolar patients with low premorbid IQ and history of obstetric complications may represent a subgroup with lower cognitive performance and psychosocial functioning.