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.     

Neuropsychological impairment among manic, depressed, and mixed-episode inpatients with bipolar disorder

Previous research has demonstrated broad neurobehavioral abnormalities in bipolar affective disorder (cf. G. Cassens, L. Wolfe, & M. Zola, 1990). However, there have been no comparisons of neuropsychological function across patients with manic, depressed, or mixed subtypes. In the present study, 37 manic, 24 mixed-episode, and 25 depressed bipolar I inpatients and 34 control subjects were administered a brief battery of neuropsychological tests. The multivariate and univariate effects of participant group on the neuropsychological measures were uniformly significant (p < .05). Planned contrasts revealed that the bipolar participants performed worse than the controls, and few differences existed between the 3 patient groups. Additionally, the bipolar groups were impaired on 50% of the test battery. These abnormalities were unlikely attributable to differences in psychiatric symptomatology, medical illness, comorbid psychiatric diagnoses, or medication status. Findings imply that acute mood disturbance during bipolar disorder yields significant neurobehavioral dysfunction.     

Neuropsychological correlates of ADHD symptoms in preschoolers

The authors examined the neuropsychological status of 22 preschoolers at risk for attention-deficit/hyperactivity disorder (ADHD) and 50 matched control children, using measures of nonverbal working memory, perceptual and motor inhibition, and memory for relative time. All tasks included paired control conditions, which allowed for the isolation of discrete executive function constructs. Group differences were evident on several measures of neuropsychological functioning; however, after accounting for nonexecutive abilities, no deficits could be attributed to specific functions targeted by the tasks. Performance on executive measures was not related to objective indices of activity level or ratings of ADHD symptoms. Yet, the fact that at-risk preschoolers were highly symptomatic casts doubt on whether executive function deficits and/or frontostriatal networks contribute etiologically to early behavioral manifestations of ADHD.     

Attention Deficit Hyperactivity Disorder and Enuresis in Children and Adolescents

The incidences of comorbid disorders and the status of neuropsychological executive functions were evaluated in two groups of patients aged 5–14 years: patients with attention deficit hyperactivity disorder (ADHD) in combination with enuresis (53 patients) and ADHD without enuresis (71 patients). Most cases of enuresis among patients of group 1 (50 of 53) had primary nocturnal enuresis. This group showed a significant increase in the total number of cases of comorbidity with such disorders as oppositional-defiant behavioral disorder, anxiety disorders, ticks, and encopresis, seen in 77.7% of cases as compared with 60.6% in group 2. The presence of enuresis in patients with ADHD was associated with a significant increase in the incidence of anxiety disorders (54.7% as compared with 39.4%). In addition, at age 5–9 years, patients with ADHD with enuresis had a tendency to a higher frequency of oppositional-defiant behavioral disorder and encopresis; those aged 10–14 years showed an increase in the proportion with obsessive-compulsive disorder and tics as compared with patients with ADHD without enuresis. Assessment of measures of executive functions using the Wisconsin card sorting test revealed no differences between patients of the two groups.     

The relationship of malingering test failure to self-reported symptoms and neuropsychological findings in adults referred for ADHD evaluation

Diagnosis of adult attention-deficit/hyperactivity disorder (ADHD) adults is difficult, as neither symptom report nor neuropsychological findings are specific to ADHD. Few studies address the possibility that noncredible performance influences both symptom report and neuropsychological findings. The present study utilized archival data from young adults referred for concerns about ADHD, divided into three groups: (1) those who failed a measure of noncredible performance (the Word Memory Test; WMT), (2) those who met diagnostic criteria for ADHD, and (3) controls with psychological symptoms but no ADHD. Results showed a 31% failure rate on the WMT. Those who failed the WMT showed clinical levels of self-reported ADHD symptoms and impaired neuropsychological performance. Neither self-report measures nor neuropsychological tests could distinguish ADHD from psychological controls, with the exception of self-reported current hyperactive/impulsive symptoms and Stroop interference. Results underscore the effect of noncredible performance on both self-report and cognitive measures in ADHD.     

Inhibitory capacity in adults with symptoms of Attention Deficit/Hyperactivity Disorder (ADHD).

Adult participants for the current study were placed into one of two groups depending on whether they manifested either high or low symptom levels of Attention Deficit/Hyperactivity Disorder (ADHD) as determined by the Wender Utah Rating Scale. Participants were also assessed on a battery of cognitive tasks as well as symptoms of depression, anxiety and substance abuse. The ADHD symptom groups were comparable in age and symptoms of depression, anxiety, and substance abuse. Adults with greater ADHD symptomatology performed more poorly on cognitive measures of response inhibition (the Stop-Signal task) and visual attention, compared to those with fewer ADHD symptoms. Regression analysis indicated the Stop-Signal task accounted for a greater proportion of the variance of ADHD symptomatology than any other cognitive variable. The conclusions from the findings are discussed in relation to self-regulation model of ADHD.     

Differentiation of executive and attention impairments in affective illness

BACKGROUND: Executive impairments have been reported in affective illness, but the influence of attention on executive performance has not been fully considered. The purpose of this study was to investigate whether executive impairments in affective illness were independent of attention impairments, and whether independent executive impairments were specific to bipolar (BP) affective illness. METHOD: Forty-two individuals with major affective disorders [20 unipolar (UP) depression and 22 BP disorder] were compared with 40 healthy controls on measures of attention and executive function. None of the patients were currently experiencing an episode of affective illness. RESULTS: As expected, both UP and BP patient groups showed significant neuropsychological impairments relative to controls. Significant differences in performance on executive function measures were also observed between UP and BP patients, even after the influence of attention had been taken into account. These impairments were not attributable to current levels of affective symptomatology or to medication. CONCLUSIONS: A single neuropsychological dissociation appears to be present between UP and BP affective illness, with BP individuals showing a specific executive deficit that is independent of attention impairment on the Hayling Sentence Completion Test (HSCT).     

Comorbidity of ADHD and Dyslexia

Comorbidity of attention deficit hyperactivity disorder (ADHD) and reading disorder (RD) is frequent. Comorbid subjects show a neuropsychological profile characterized by failure of various cognitive functions with an additive-effect that can determine more severe functional deficits. Comorbid RD may be a marker for a group of children with ADHD with more severe cognitive deficits, and a worse neuropsychological, academic, and behavioral outcome. The article focuses on the link between RD and ADHD from an epidemiological, genetic, neurofunctional, neuropsychological, and therapeutic perspective and summarizes the characteristics of the comorbid phenotype.     

Brief report: cognitive functioning in children with Tourette's syndrome with and without comorbid ADHD

OBJECTIVE: To examine whether patients with Tourette's syndrome (TS) with and without comorbid attention deficit and hyperactivity disorder (ADHD) differ in cognitive functioning and whether a higher level of cognitive functioning is associated with severity of TS symptoms and psychosocial functioning. METHODS: Cognitive functioning, symptom severity, and psychosocial functioning were examined in 40 patients (33 boys, 7 girls; age range 6-18 years) with TS, of whom 17 had the comorbid diagnosis of ADHD. RESULTS: Patients with a comorbid ADHD diagnosis evidenced poorer performance than those with TS alone with respect to severity of TS symptoms, psychosocial functioning, verbal and performance intelligence, and word fluency, but not on tests of cognitive flexibility. Psychosocial functioning was predicted by symptom severity, but not by intelligence or fluency. CONCLUSIONS: Results confirm prior findings that comorbid ADHD is associated with more TS symptoms and worse psychosocial and cognitive functioning, and motivate whether cognitive flexibility plays a role in moderating the deleterious psychosocial effects of Tourette's syndrome and ADHD.     

Learning disabilities and executive dysfunction in boys with attention-deficit/hyperactivity disorder

The effect of comorbid reading or arithmetic learning disabilities (LDs) on neuropsychological function in attention-deficit/hyperactivity disorder (ADHD) was studied. Participants were young males diagnosed with ADHD, with and without LD, and non-ADHD, non-LD male controls of similar age. LD was defined by combined regression-based and low-achievement classifications. Analyses adjusted for the effect of psychiatric comorbidity, age, and socioeconomic status on neuropsychological function. Children who had both ADHD and LD were significantly more impaired on both executive and nonexecutive functions than ADHD children without LD. Neuropsychological performance was most impaired in ADHD with combined arithmetic and reading disability. These data indicate that comorbid LD, especially arithmetic disability, significantly increases the severity of executive function impairment in ADHD.     

Differential performance on tasks of affective processing and decision-making in patients with Panic Disorder and Panic Disorder with comorbid Major Depressive Disorder

BACKGROUND: Neuropsychological studies have provided evidence for deficits in psychiatric disorders, such as schizophrenia and mood disorders. However, neuropsychological function in Panic Disorder (PD) or PD with a comorbid diagnosis of Major Depressive Disorder (MDD) has not been comprehensively studied. The present study investigated neuropsychological functioning in patients with PD and PD + MDD by focusing on tasks that assess attention, psychomotor speed, executive function, decision-making, and affective processing. METHODS: Twenty-two unmedicated patients with PD, eleven of whom had a secondary diagnosis of MDD, were compared to twenty-two healthy controls, matched for gender, age, and intelligence on tasks of attention, memory, psychomotor speed, executive function, decision-making, and affective processing from the Cambridge Neuropsychological Test Automated Battery (CANTAB), Cambridge Gamble Task, and Affective Go/No-go Task. RESULTS: Relative to matched healthy controls, patients with PD + MDD displayed an attentional bias toward negatively-valenced verbal stimuli (Affective Go/No-go Task) and longer decision-making latencies (Cambridge Gamble Task). Furthermore, the PD + MDD group committed more errors on a task of memory and visual discrimination compared to their controls. In contrast, no group differences were found for PD patients relative to matched control subjects. LIMITATIONS: The sample size was limited, however, all patients were drug-free at the time of testing. CONCLUSIONS: The PD + MDD patients demonstrated deficits on a task involving visual discrimination and working memory, and an attentional bias towards negatively-valenced stimuli. In addition, patients with comorbid depression provided qualitatively different responses in the areas of affective and decision-making processes.     

The intermediate visual and auditory continuous performance test as a neuropsychological measure.

The Intermediate Visual and Auditory (IVA) Continuous Performance Test (CPT) and Neuropsychological Impairment Scale (NIS) were completed with adults diagnosed with mild traumatic brain injury (mTBI), adults diagnosed with Attention Deficit Hyperactivity Disorder (ADHD), and controls. On the IVACPT, the mTBI and ADHD groups performed significantly lower on the full and secondary scales for attention and response accuracy. For individual scales, the mTBI and ADHD groups showed lower performance on measures of reaction time, inattention, impulsivity, and variability of RT. The mTBI and ADHD groups showed similar patterns of performance on the IVA. On the NIS, the mTBI and ADHD groups reported more neuropsychological symptoms than the control group and the mTBI group reported more neuropsychological symptoms than the ADHD group. The results are discussed in regard to changes in cognitive processing and sustained attention in individuals diagnosed with mTBI and ADHD.     

The Integrated Visual and Auditory Continuous Performance Test as a neuropsychological measure.

The Integrated Visual and Auditory (IVA) Continuous Performance Test (CPT) and Neuropsychological Impairment Scale (NIS) were completed by adults diagnosed with mild traumatic brain injury (mTBI), adults diagnosed with attention deficit hyperactivity disorder (ADHD), and controls. On the IVA CPT, the mTBI and ADHD groups performed significantly lower on the full and secondary scales for attention and response accuracy. For individual scales, the mTBI and ADHD groups showed lower performance on measures of reaction time, inattention, impulsivity, and variability of RT. The mTBI and ADHD groups showed similar patterns of performance on the IVA. On the NIS, the mTBI and ADHD groups reported more neuropsychological symptoms than the control group, and the mTBI group reported more neuropsychological symptoms than the ADHD group. The results are discussed in regard to changes in cognitive processing and sustained attention in individuals diagnosed with mTBI and ADHD.     

Sleep in adults with attention deficit hyperactivity disorder (ADHD) before and during treatment with methylphenidate: a controlled polysomnographic study

STUDY OBJECTIVES: Sleep problems are frequently associated with childhood ADHD, as indicated by numerous polysomnographic investigations showing increased nocturnal movements, reduced sleep efficiency, and decreased percentage of REM sleep (although findings are not consistent over all studies). Data on objective and subjective sleep parameters in adults with ADHD are sparse, and to date the impact of stimulants, the most widely used pharmacological treatment for ADHD, on sleep in adults with ADHD has not been examined. Thus the objectives of our study were to assess objective and subjective sleep parameters in adults with ADHD and the impact of stimulant medication on sleep. DESIGN: Two-group comparison and open-label therapy study. PARTICIPANTS: We enrolled 34 nonmedicated patients with ADHD, of whom 24 were without current comorbid psychiatric disorders, and 34 sex- and gender-matched control subjects without current psychiatric disorders or psychotropic medication. INTERVENTIONS: Ten patients were treated with methylphenidate over > or =26 days with a mean daily dose of 36.7 +/- 11.2 mg. MEASUREMENTS: Polysomnographic recording over 2 consecutive nights as well as assessments of subjective sleep parameters were performed in all patients and controls before treatment and reassessed in those patients receiving methylphenidate. RESULTS: Compared to controls untreated patients showed increased nocturnal activity, reduced sleep efficiency, more nocturnal awakenings and reduced percentage of REM sleep. Treatment with methylphenidate resulted in increased sleep efficiency as well as a subjective feeling of improved restorative value of sleep. CONCLUSIONS: Sleep problems in patients with ADHD continue from childhood to adulthood, with similar objective sleep characteristics in adults and children with ADHD. Medication with methylphenidate appears to have beneficial effects on sleep parameters in adults with ADHD.     

The concept of post-traumatic mood disorder

Post-traumatic stress disorder (PTSD) is frequently comorbid with depression. A number of studies have been conducted to compare individuals suffering from comorbid PTSD and depression with individuals suffering from PTSD alone or depression alone. Comorbidity of PTSD and depression is associated with more severe symptoms as well as higher levels of disability compared to individuals with PTSD alone. A severity of overall symptoms is three to fivefold greater in subjects with comorbid PTSD and depression compared to those with PTSD alone. The comorbid group is five times more likely to manifest functional impairment compared to those diagnosed with PTSD alone. Patients with comorbid PTSD and depression have higher depression, impulsivity, and hostility scores and are significantly more likely to make a suicide attempt compared to subjects with depression alone. Depressed subjects with comorbid PTSD tend towards earlier age of first hospitalization and a higher number of hospitalizations compared to depressed individuals without comorbid PTSD. Lower affinity of alpha-2 adrenoreceptors and higher plasma tyrosine availability to the brain are associated with comorbid PTSD and depression, but not with PTSD alone. Individuals with comorbid PTSD and depression do not exhibit the classic rapid eye movement sleep architectural modifications associated with depression, despite the fact that several other psychophysiological indices of dysphoria are detectable in their sleep. In fenfluramine challenge studies, depressed patients with comorbid PTSD have lower plasma cortisol compared to depressed patients without comorbid PTSD. Cortisol levels increase with age and the number of previous major depressive episodes is a predictor of the cortisol response to fenfluramine administration in depressed patients without PTSD, but not in depressed patients with comorbid PTSD. Depressed subjects with comorbid PTSD have higher cerebrospinal fluid homovanillic acid levels compared with depressed subjects without comorbid PTSD. Thus, studies suggest that patients suffering from comorbid PTSD and depression differ clinically and biologically from individuals with PTSD alone or depression alone. It is possible that some or all individuals diagnosed with comorbid PTSD and depression have a separate psychobiological condition that can be termed "post-traumatic mood disorder". Future clinical and neurobiological studies may not only advance our understanding of the role of environmental and genetic factors in the etiology and pathogenesis of stress-related disorders, but also be useful in refining conceptions of stress-related disorders themselves and possible approaches to the treatment of these conditions.     

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.     

Neuropsychological measures probably facilitate heritability research of ADHD

Previous studies, in which cognitive and motor neuropsychological tasks were administered to 816 children from Attention-Deficit/Hyperactivity Disorder (ADHD)- and control-families, showed that various of these measures appeared useful for genetic research in ADHD by forming candidate endophenotypes: underlying, heritable, vulnerability traits that mark an enhanced liability for developing ADHD. The current study extends these findings by showing that six of these ten measures correlate more strongly between siblings than an ADHD composite, suggesting these measures may have a larger heritability than ADHD itself. Significant sibling cross-correlations also suggested that six of ten neuropsychological measures related to similar familial (and heritable) factors as ADHD, suggesting these measures to be useful for ADHD genetic research. An aggregated neuropsychological composite appeared to be the most powerful, since it correlated more strongly between siblings than most individual task measures. These findings suggest heritability research in ADHD will probably be facilitated by including neuropsychological measures.     

Sleep in adults with attention-deficit/hyperactivity disorder: a controlled polysomnographic study including spectral analysis of the sleep EEG

STUDY OBJECTIVES: Previous studies in children with attention-deficit/hyperactivity disorder and attention deficit disorder (ADHD/ADD) have shown impaired sleep quality with increased nocturnal motor activity. However, polysomnographic findings are not unequivocal. Up to now, in adults with ADHD, only 1 case-control polysomnographic study with small sample size has been performed. We investigated objective and subjective sleep quality in adultADHD, including an electroencephalogram spectral power analysis. DESIGN: Single-blind comparative study. SETTING: University medical center. PARTICIPANTS: Twenty adult unmedicated ADHD patients without current comorbid major depression, drug abuse, or comorbid axis-II disorder and 20 sex- and age-matched control subjects. INTERVENTIONS: N/A. MEASUREMENTS: Conventional polysomnographic parameters and sleep electroencephalogram spectral power analysis was calculated for the 2 laboratory nights. Subjective sleep parameters were estimated by sleep questionnaires to assess the relationship between objective and subjective sleep measurements. RESULTS: Adult ADHD patients showed increased nocturnal motor activity (as indicated by heightened indexes of periodic leg movements in sleep), which was significantly inversely correlated with subjective total sleep time. Although ADHD patients displayed significantly increased objective total sleep time, the subjective ratings documented impaired sleep quality in those with ADHD. Other polysomnographic sleep patterns and spectral electroencephalogram parameters did not differ between ADHD patients and normal controls. CONCLUSIONS: Similar to children, adults with ADHD show increased nocturnal motor activity. Otherwise, sleep does not seem to be impaired in ADHD patients. However, the dissociation between objective and subjective sleep parameters points to a misinterpretation of sleep quality in patients with ADHD.     

Asthma medication may influence the psychological functioning of children

Asthma is a global health problem with up to 15% of children suffering from the disease. It has been shown by various researchers that symptomatic asthmatic patients have increased levels of free serotonin in plasma when compared with asymptomatic patients. Thus, some researchers suggest that reducing the concentration of free serotonin in plasma might be useful in treating patients with asthma. Low levels of serotonin, has however, been linked to various psychological conditions like depression, oppositional defiant disorder, ADHD and even conduct disorder. Research has indicated that products like methylphenidate (also known by the brand names as e.g., Ritalin, Concerta, Metadate and others) and other stimulants used for these conditions, particularly ADHD, exert their paradoxical calming effects by boosting serotonin levels in the brain. Therefore, the hypothesis suggest that some children using asthma medication that lowers serotonin levels, might present with symptoms of depression ADHD, oppositional defiant disorder and even conduct disorder. They may be using asthma medication that lowers serotonin and additionally use methylphenidate that boosts serotonin levels for e.g., ADHD. The hypothesis therefore suggests that asthmatic children presenting with psychological complaints, be treated holistically and serotonin levels measured before coming to conclusions regarding their psychological functioning.     

Understanding comorbidity: a twin study of reading disability and attention-deficit/hyperactivity disorder.

A community sample of twins in which at least one member of each pair exhibited significant reading difficulties (99 monozygotic and 80 dizygotic pairs) or symptoms of attention-deficit/hyperactivity disorder (ADHD; 83 monozygotic and 78 dizygotic pairs) was used to test the etiology of comorbidity between reading disability (RD) and ADHD. Univariate analyses revealed moderate to high heritability for all measures of reading difficulty and ADHD. Subsequent bivariate analyses indicated that the relation between reading difficulties and inattention symptoms is primarily attributable to common genetic influences, whereas bivariate heritability estimates were not significant for hyperactivity-impulsivity and any of the reading measures. Reading difficulties and ADHD symptoms were more highly heritable if the proband met criteria for both disorders versus RD or ADHD alone, suggesting that future molecular genetic analyses of comorbid RD + ADHD may facilitate the identification of susceptibility genes for RD, ADHD, and their comorbidity.