Attention-deficit/hyperactivity disorder in adults: an overview

Efficacy and Safety of Atomoxetine Hydrochloride in Asian Adults With ADHD

OBJECTIVE

The efficacy and safety of atomoxetine was assessed in adult ADHD patients from Japan, Korea, and Taiwan in this first placebo-controlled Asian clinical study in adults of an ADHD medication.

METHOD

Atomoxetine was compared with placebo (195 atomoxetine, 196 placebo) over 10 weeks. The change from baseline to endpoint and changes over time in the Conners' Adult ADHD Rating Scale-Investigator Rated: Screening Version total score (CAARS-Inv: SV total score) were assessed along with changes in quality of life (QoL) and executive function.

RESULTS

Atomoxetine treatment resulted in a mean reduction of -14.3 (placebo, -8.8) in CAARS-Inv: SV total score and a steady increase of between-group differences from Week 2. Improvements in QoL and executive functioning were also observed. Treatment-emergent adverse events leading to discontinuation were infrequent (atomoxetine: 5.2%, placebo: 1.5%).

CONCLUSION

Atomoxetine was tolerable and effective in improving QoL and executive function as well as ameliorating core ADHD symptoms in adult Asian patients.

The development of the SGI-16: a shortened sensory gating deficit and distractibility questionnaire for adults with ADHD

The Sensory Gating Inventory (SGI) is a questionnaire composed of 36 items designed to investigate abnormal perception related to the inability to control sensitivity to sensory stimuli frequently reported in adult with ADHD. This questionnaire can be considered too lengthy to be taken by people with ADHD, and a shortened version is needed. One hundred and sixty-three adults with ADHD responded to the SGI-36. An item reduction process took into account both the results of statistical analyses and the expertise of a steering committee. Construct validity, reliability, and external validity were tested for a short version (16 items). The structure of the SGI-16 was confirmed by principal components factor analysis. Cronbach's alpha coefficients ranged from 0.78 to 0.89. The SGI-16 dimension scores were highly correlated with their respective SGI-36 dimension scores. The SGI-16 seems to be both appropriate and useful for use in clinical practice to investigate perceptual abnormalities in adults with ADHD.

Childhood Factors Affecting Persistence and Desistence of Attention-Deficit/Hyperactivity Disorder Symptoms in Adulthood: Results From the MTA

OBJECTIVE

To determine childhood factors that predict attention-deficit/hyperactivity disorder (ADHD) persistence and desistence in adulthood.

METHOD

Regression analyses were used to determine associations between childhood factors and adult ADHD symptom persistence in 453 participants (mean age, 25 years) from the Multimodal Treatment Study of Children with ADHD (MTA). Childhood IQ, total number of comorbidities, child-perceived parenting practices, child-perceived parent-child relationships, parental mental health problems, marital problems of parents, household income levels, and parental education were assessed at a mean age of 8 years in all participants. Adult ADHD persistence was defined using DSM-5 symptom counts either with or without impairment, as well as mean ADHD symptom scores on the Conners' Adult ADHD Rating Scale (CAARS). Age, sex, MTA site, and childhood ADHD symptoms were covaried.

RESULTS

The most important childhood predictors of adult ADHD symptom persistence were initial ADHD symptom severity (odds ratio [OR] = 1.89, standard error [SE] = 0.28, p = .025), comorbidities (OR = 1.19, SE = 0.07, p = .018), and parental mental health problems (OR = 1.30, SE = 0.09, p = .003). Childhood IQ, socioeconomic status, parental education, and parent-child relationships showed no associations with adult ADHD symptom persistence.

CONCLUSION

Initial ADHD symptom severity, parental mental health, and childhood comorbidity affect persistence of ADHD symptoms into adulthood. Addressing these areas early may assist in reducing adult ADHD persistence and functioning problems.

Gender ratios of administrative prevalence and incidence of attention-deficit/hyperactivity disorder (ADHD) across the lifespan: A nationwide population-based study in Taiwan

To verify the hypothesis that there is different gender ratio of attention-deficit/hyperactivity disorder (ADHD) among adults compared to children and adolescents in the clinical setting among Asian population. The nationwide population-based database containing data on enrollees in the National Health Insurance program in Taiwan during 2000-2007 was used in this study, and we investigated the lifetime gender ratios of administrative prevalence and incidence in healthcare-seeking ADHD patients (n=228,029). The male-to-female ratios of diagnosed incidence and prevalence of child/adolescent ADHD (age <20 years) ranged from 3.39 to 4.07 and 3.87-4.31, respectively. The male-to-female ratios of diagnosed incidence and prevalence of ADHD in the adult group (age 20-65 years) ranged from 0.24 to 0.76 and 0.35-0.98, respectively. In conclusion, there was substantially increased female-to-male ratio in adults ADHD compared to children and adolescents in the clinical setting. Further researches on the management and mechanism are needed.

The Groundskeeper Gaming Platform as a Diagnostic Tool for Attention-Deficit/Hyperactivity Disorder: Sensitivity, Specificity, and Relation to Other Measures

OBJECTIVE

The purpose of this study was to assess the relative accuracies of the Conners' Brief Rating Scale, Parent Version, the Conners' Continuous Performance Test II (CPT II), and a novel interactive game called "Groundskeeper" to discriminate child psychiatric patients with and without attention-deficit/hyperactivity disorder (ADHD).

METHODS

We administered the three assessments to 113 clinically referred ADHD and non-ADHD patients who had been diagnosed with the Kiddie-Schedule of Affective Disorders and Schizophrenia- Present and Lifetime (K-SADS-PL), Version 19.

RESULTS

As measured by the area under the curve (AUC) statistic from receiver operating characteristic (ROC) analysis, the diagnostic accuracy of Groundskeeper (0.79) was as high as the accuracy of the Conners' parent rating of inattention (0.76) and better than the CPT II percent correct (0.62). Combining the three tests produced an AUC of 0.87. Correlations among the three measures were small and, mostly, not significant.

CONCLUSIONS

Our finding of similar diagnostic accuracies between Groundskeeper and the Conners' inattention scale is especially remarkable given that the Conners' inattention scale shares method variance with the diagnostic process. Although our work is preliminary, it suggests that computer games may be useful in the diagnostic process. This provides an important direction for research, given the objectivity of such measures and the fact that computer games are well tolerated by youth.

Exome chip analyses in adult attention deficit hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable childhood-onset neuropsychiatric condition, often persisting into adulthood. The genetic architecture of ADHD, particularly in adults, is largely unknown. We performed an exome-wide scan of adult ADHD using the Illumina Human Exome Bead Chip, which interrogates over 250 000 common and rare variants. Participants were recruited by the International Multicenter persistent ADHD CollaboraTion (IMpACT). Statistical analyses were divided into 3 steps: (1) gene-level analysis of rare variants (minor allele frequency (MAF)<1%); (2) single marker association tests of common variants (MAF⩾1%), with replication of the top signals; and (3) pathway analyses. In total, 9365 individuals (1846 cases and 7519 controls) were examined. Replication of the most associated common variants was attempted in 9847 individuals (2077 cases and 7770 controls) using fixed-effects inverse variance meta-analysis. With a Bonferroni-corrected significance level of 1.82E-06, our analyses of rare coding variants revealed four study-wide significant loci: 6q22.1 locus (P=4.46E-08), where NT5DC1 and COL10A1 reside; the SEC23IP locus (P=6.47E-07); the PSD locus (P=7.58E-08) and ZCCHC4 locus (P=1.79E-06). No genome-wide significant association was observed among the common variants. The strongest signal was noted at rs9325032 in PPP2R2B (odds ratio=0.81, P=1.61E-05). Taken together, our data add to the growing evidence of general signal transduction molecules (NT5DC1, PSD, SEC23IP and ZCCHC4) having an important role in the etiology of ADHD. Although the biological implications of these findings need to be further explored, they highlight the possible role of cellular communication as a potential core component in the development of both adult and childhood forms of ADHD.

The Relationship of Attention Deficit Hyperactivity Disorder to Crime and Delinquency: A Meta-Analysis

In recent years, criminologists have begun to focus more closely on how certain biosocial and/or neuropsychological factors may influence criminal and delinquent behaviour. One factor that is emerging as a potentially important correlate of such behaviour is Attention Deficit — often combined with hyperactivity — Disorder (ADD and/or ADHD). The results of the growing body of empirical literature assessing this link are, however, inconsistent. The present study subjects this body of research to a ‘meta-analysis' — or, ‘quantitative synthesis' — to establish both the overall effect of ADHD on crime and delinquency and the degree to which this relationship is conditioned by methodological factors across empirical studies. The analyses reveal a fairly strong association between measures of ADHD and criminal/delinquent behaviour. Nevertheless, these effects are not invariant across certain salient methodological characteristics. The implications for criminological theory and correctional policy are discussed.

Single-dose effects on the P3no-go ERP component predict clinical response to stimulants in pediatric ADHD

OBJECTIVE

Approximately 30% of children and adolescents diagnosed with attention-deficit/hyperactivity disorder (ADHD) and treated with stimulants are considered non-responders (non-REs). Reliable predictors of response are missing. We examined changes in Event-Related Potentials (ERPs) induced by a single dose of stimulant medication in order to predict later clinical response.

METHODS

ERPs were registered twice during performance of a visual cued go/no-go task in 87 ADHD patients (27 girls) aged 8-18years; the second recording on a single dose of stimulant medication, followed by a systematic medication trial lasting 4weeks. Based on the four-week trial, participants were categorized as responders (REs, N=62) or non-REs (N=25). Changes among REs and non-REs in ERP components (cueP3, CNV, P3go, N2no-go, P3no-go) and behavioral-test variables were then compared.

RESULTS

REs and non-REs differed significantly in medication-induced changes in P3no-go, cue-P3, CNV, omission errors, reaction time, and reaction-time variability. The largest effect size was found for P3no-go amplitude (p<.001; d=1.76). Changes in P3no-go and omission errors correctly classified 90% of the REs and 76% of the non-REs, when controlling for the age of the participants.

CONCLUSION

Clinical response to stimulants can be predicted by assessing single-dose changes in the P3no-go ERP component amplitude.

SIGNIFICANCE

Changes in P3no-go may be a clinically useful marker of response to stimulants.

Melatonin in Youth: N-of-1 trials in a stimulant-treated ADHD Population (MYNAP): study protocol for a randomized controlled trial

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a common neurological disorder affecting 5 % of children worldwide. A prevalent problem for children with ADHD is initial insomnia. The gold standard treatment to manage ADHD symptoms is stimulant medications, which may exacerbate the severity of existing initial insomnia. Currently, no gold standard treatment option exists for initial insomnia for these children. Melatonin, a hormone and a popular natural health product, is commonly provided to children by parents and recommended by healthcare providers, but high quality pediatric evidence is lacking.

METHODS/DESIGN

This trial is a multicenter randomized triple-blind, placebo-controlled, parallel-group, randomized, controlled trial (RCT), in which each participant is offered an N-of-1 trial. An N-of-1 trial is a multiple-crossover, randomized, controlled trial conducted in a single individual. For the N-of-1 trial, each participant will undergo three pairs of treatment/placebo periods; each period is 1 week in length. Half the participants will have melatonin in the first period, the other half will start with placebo, and this will make up the parallel-group RCT. The primary outcome will be mean difference in sleep onset latency as measured by sleep diaries. A comparison of treatment effects yielded by the RCT data versus the aggregated N-of-1 trial data will also be assessed.

DISCUSSION

This trial will provide rigorous evidence for the effectiveness of melatonin in children with ADHD on stimulants who experience initial insomnia. Further, this study will provide the first prospectively planned head-to-head comparison of RCT data with pooled data from a series of N-of-1 trials. Aggregated N-of-1 trials may be a powerful tool to produce high quality clinical trial evidence.

TRIAL REGISTRATION NUMBERS

ClinicalTrials.gov, NCT02333149 . Registered on 16 December 2014. Australian New Zealand Clinical Trials Registry, ACTRN12614000542695 . Registered on 21 May 2014.

Girl, Repeatedly Interrupted

Attention deficit/hyperactivity disorder (ADHD) is the most prevalent behavioral disorder among children in the United States. Although symptoms may remit over time for some individuals diagnosed with ADHD in childhood, a significant number continue to report clinically significant impairment into adolescence and adulthood. The specific difficulties encountered by adults with ADHD are just starting to be understood and studied. In particular, the long-standing difficulties encountered by females first identified with ADHD in adulthood have apparently been greatly underreported. The goal of this article is to discuss the case of a young woman, Amanda, who is first diagnosed with ADHD after encountering difficulties during her freshman year of college. Her case demonstrates the importance of an accurate diagnosis and the benefit of a course of cognitive-behavioral psychotherapy combined with standard pharmacotherapy for adult ADHD.

Evaluation of the Persistence, Remission, and Emergence of Attention-Deficit/Hyperactivity Disorder in Young Adulthood

IMPORTANCE

Attention-deficit/hyperactivity disorder (ADHD) is now recognized to occur in adulthood and is associated with a range of negative outcomes. However, less is known about the prospective course of ADHD into adulthood, the risk factors for its persistence, and the possibility of its emergence in young adulthood in nonclinical populations.

OBJECTIVE

To investigate childhood risk factors and young adult functioning of individuals with persistent, remitted, and late-onset young adult ADHD.

DESIGN, SETTING, AND PARTICIPANTS

The study sample was the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally representative birth cohort of 2232 twins born in England and Wales from January 1, 1994, to December 4, 1995. Evaluation of childhood ADHD (ages 5, 7, 10, and 12 years) included prenatal and perinatal factors, clinical characteristics, and aspects of the family environment. Among participants aged 18 years, ADHD symptoms and associated impairment, overall functioning, and other mental health disorders were examined. Data analysis was conducted from February 19 to September 10, 2015.

MAIN OUTCOMES AND MEASURES

Attention-deficit/hyperactivity disorder according to DSM-IV diagnostic criteria in childhood and DSM-5 diagnostic criteria in young adulthood.

RESULTS

Of 2232 participants in the E-Risk Study, 2040 were included in the present analysis. In total, 247 individuals met diagnostic criteria for childhood ADHD; of these, 54 (21.9%) also met diagnostic criteria for the disorder at age 18 years. Persistence was associated with more symptoms (odds ratio [OR], 1.11 [95% CI, 1.04-1.19]) and lower IQ (OR, 0.98 [95% CI, 0.95-1.00]). At age 18 years, individuals with persistent ADHD had more functional impairment (school/work: OR, 3.30 [95% CI, 2.18-5.00], home/with friends: OR, 6.26 [95% CI, 3.07-12.76]), generalized anxiety disorder (OR, 5.19 [95% CI, 2.01-13.38]), conduct disorder (OR, 2.03 [95% CI, 1.03-3.99]), and marijuana dependence (OR, 2.88 [95% CI, 1.07-7.71]) compared with those whose ADHD remitted. Among 166 individuals with adult ADHD, 112 (67.5%) did not meet criteria for ADHD at any assessment in childhood. Results from logistic regressions indicated that individuals with late-onset ADHD showed fewer externalizing problems (OR, 0.93 [95% CI, 0.91-0.96]) and higher IQ (OR, 1.04 [95% CI, 1.02-1.07]) in childhood compared with the persistent group. However, at age 18 years, those with late-onset ADHD demonstrated comparable ADHD symptoms and impairment as well as similarly elevated rates of mental health disorders.

CONCLUSIONS AND RELEVANCE

We identified heterogeneity in the DSM-5 young adult ADHD population such that this group consisted of a large, late-onset ADHD group with no childhood diagnosis, and a smaller group with persistent ADHD. The extent to which childhood-onset and late-onset adult ADHD may reflect different causes has implications for genetic studies and treatment of ADHD.

ADHD in context: Young adults' reports of the impact of occupational environment on the manifestation of ADHD

Does changing context play a role in the decline in ADHD symptoms in adulthood? Insufficient research has explored the functioning of adults with ADHD. As adults, individuals with ADHD have significantly more latitude to control aspects of their day-to-day environments. Do the new contexts young adults find themselves in alter their experience of ADHD? Are there particular occupational or educational contexts in which young adults report functioning better than others? To examine this issue, we conducted semi-structured interviews at four North American sites in 2010-11 with 125 young adults, originally diagnosed with ADHD as children, regarding their work and post-secondary educational environments. Many subjects describe their symptoms as context-dependent. In some contexts, participants report feeling better able to focus; in others, their symptoms-such as high energy levels-become strengths rather than liabilities. Modal descriptions included tasks that were stressful and challenging, novel and required multitasking, busy and fast-paced, physically demanding or hands-on, and/or intrinsically interesting. Consistent with a developmental psychopathology framework, ADHD is experienced as arising from an interaction between our subjects and their environments. These findings demonstrate the need to account for the role of context in our understanding of ADHD as a psychiatric disorder, especially as it manifests in young adulthood.

Adult attention-deficit/hyperactivity disorder and its association with substance use and substance use disorders in young men

BACKGROUND

Functional and mental health impairments that adults with attention-deficit/hyperactivity disorder (ADHD) experience may be exacerbated by regular substance use and co-morbidity with substance use disorders (SUD). This may be especially true during young adulthood, which represents a critical stage of life associated with increased substance use and associated problems. However, previous studies investigating the association between ADHD and substance use and SUD have demonstrated inconsistent results, probably due to methodological limitations (e.g., small and non-representative samples). Thus, the relationship of ADHD with substance use and related disorders remains unclear. The aim of the present study was to examine the association between ADHD and both the use of licit and illicit substances and the presence of SUD in a large, representative sample of young men.

METHOD

The sample included 5677 Swiss men (mean age 20 ± 1.23 years) who participated in the Cohort Study on Substance Use Risk Factors (C-SURF). ADHD was assessed using the adult ADHD Self Report Screener (ASRS). The association between ADHD and substance use and SUD was assessed for alcohol, nicotine, cannabis and other illicit drugs, while controlling for socio-demographic variables and co-morbid psychiatric disorders (i.e., major depression (MD) and anti-social personality disorder (ASPD)).

RESULTS

Men with ADHD were more likely to report having used nicotine, cannabis and other illicit drugs at some time in their life, but not alcohol. ADHD was positively associated with early initiation of alcohol, nicotine and cannabis use, the risky use of these substances, and the presence of alcohol use disorders, and nicotine and cannabis dependence. Additionally, our analyses revealed that these patterns are also highly associated with ASPD. After adjusting for this disorder, the association between ADHD and licit and illicit substance use and the presence of SUDs was reduced, but remained significant.

CONCLUSIONS

Our findings suggest that adult ADHD is significantly associated with a propensity to experiment with licit and illicit substances, especially at earlier ages, to exhibit risky substance use patterns, and to subsequently develop SUDs. Preventive strategies that include early intervention and addressing co-morbidity with ASPD may be crucial to reducing substance use and the development of pathological substance use patterns in young men affected by ADHD and, thus, helping to prevent further illness burden later in life.

Psychiatric comorbidities of adults with early- and late-onset attention-deficit/hyperactivity disorder

OBJECTIVE

We evaluated the psychiatric comorbidities in adults who were diagnosed with Diagnostic and Statistical Manual of Mental disorders, 5th edition attention-deficit/hyperactivity disorder as a function of recalled symptom onset before and after the age of 7 years and whether the childhood attention-deficit/hyperactivity disorder symptoms were associated with psychiatric comorbidities.

METHOD

In all, 214 adults who were diagnosed with Diagnostic and Statistical Manual of Mental disorders, 5th edition attention-deficit/hyperactivity disorder and 174 non-attention-deficit/hyperactivity disorder controls (aged 17-40 years) received psychiatric interviews to confirm their previous and current attention-deficit/hyperactivity disorder status and other psychiatric diagnoses. Demographics and risks of lifetime psychiatric disorders were compared among three groups: (1) attention-deficit/hyperactivity disorder, onset <7 years (early-onset); (2) attention-deficit/hyperactivity disorder, onset between 7 and 12 years (late-onset) and (3) non-attention-deficit/hyperactivity disorder controls. We also tested the effects of attention-deficit/hyperactivity disorder symptoms on the risk of later psychiatric comorbidities by Cox regression analyses.

RESULTS

Regardless of the age of onset, attention-deficit/hyperactivity disorder was significantly associated with a wide range of psychiatric comorbidities. There were similar comorbid patterns between early- and late-onset attention-deficit/hyperactivity disorder. Regardless of attention-deficit/hyperactivity disorder diagnosis, increased severity of attention-deficit/hyperactivity disorder symptoms was associated with higher risks of oppositional defiant disorder, conduct disorder, dysthymia and sleep disorder but not major depression, which was associated with the attention-deficit/hyperactivity disorder diagnosis.

CONCLUSION

Our findings suggest that elevating the threshold of age of onset to 12 years in Diagnostic and Statistical Manual of Mental disorders, 5th edition would not over-diagnose attention-deficit/hyperactivity disorder in the adult population. Recalled childhood attention-deficit/hyperactivity disorder symptom severity was correlated with conduct disorder, oppositional defiant disorder, dysthymia and sleep disorders.

EEG correlates of visual short-term memory as neuro-cognitive endophenotypes of ADHD

Attention deficit hyperactivity disorder (ADHD) frequently persists into adulthood. A reduction in visual short-term memory (vSTM) storage capacity was recently suggested as a potential neuro-cognitive endophenotype, i.e., a testable marker of an individual's liability for developing ADHD. This study aimed at identifying markers of the brain abnormalities underlying vSTM reductions in adult ADHD. We combined behavioral parameter-based assessment with electrophysiology in groups of adult ADHD patients and healthy age-matched controls. Amplitudes of ERP markers of vSTM storage capacity, the contralateral delay activity (CDA) and the P3b, were analyzed according to (i) differences between individuals with higher vs. lower storage capacity K and (ii) differences between ADHD patients and control participants. We replicated the finding of reduced storage capacity in adult ADHD. Across groups, individuals with higher relative to lower storage capacity showed a larger CDA and P3b. We further found differences between the patient and control groups in the ERPs: The CDA amplitude was attenuated in an early time window for ADHD patients compared to control participants, and was negatively correlated with ADHD patients' symptom severity ratings. Furthermore, the P3b was larger in ADHD patients relative to control participants. These electrophysiological findings indicate altered brain mechanisms underlying visual storage capacity in ADHD, which are characterized by deficient encoding and maintenance, and increased recruitment of control processes. Accordingly, (quantifiable) ERP markers of vSTM in adult ADHD bear candidacy as neuro-cognitive endophenotypes of the disease.

The Association of SNAP25 Gene Polymorphisms in Attention Deficit/Hyperactivity Disorder: a Systematic Review and Meta-Analysis

Attention deficit/hyperactivity disorder (ADHD) is one of the most highly heritable psychiatric disorders in childhood. The risk gene mutation accounts for about 60 to 90 % cases. Synaptosomal-associated protein of 25 kDa (SNAP-25) is a presynaptic plasma membrane protein which is expressed highly and specifically in the neuronal cells. A number of evidences have suggested the role of SNAP-25 in the etiology of ADHD. Notably, the animal model of coloboma mouse mutant bears a ∼2-cM deletion encompassing genes including SNAP25 and displays spontaneous hyperkinetic behavior. Previous investigators have reported association between SNPs in SNAP25 and ADHD, and controversial results were observed. In this study, we analyzed the possible association between six polymorphisms (rs3746544, rs363006, rs1051312, rs8636, rs362549, and rs362998) of SNAP25 and ADHD in a pooled sample of ten family-based studies and four case-control studies by using meta-analysis. The combined analysis results were significant only for rs3746544 (P = 0.010) with mild association (odds ratio (OR) = 1.14). And, the meta-analysis data for rs8636, rs362549, and rs362998 are the first time to be reported; however, no positive association was detected. In conclusion, we report some evidence supporting the association of SNAP25 to ADHD. Future research should emphasize genome-wide association studies in more specific subgroups and larger independent samples.

The challenges of implementing ADHD clinical guidelines and research best evidence in routine clinical care settings: Delphi survey and mixed-methods study

BACKGROUND

The landmark US Multimodal Treatment of ADHD (MTA) study established the benefits of individualised medication titration and optimisation strategies to improve short- to medium-term outcomes in attention-deficit hyperactivity disorder (ADHD). This individualised medication management approach was subsequently incorporated into the National Institute for Health and Care Excellence (NICE) ADHD Clinical Guidelines (NICE CG78). However, little is known about clinicians' attitudes towards implementing these medication management strategies for ADHD in routine care.

AIMS

To examine National Health Service (NHS) healthcare professionals' consensus on ADHD medication management strategies.

METHOD

Using the Delphi method, we examined perceptions on the importance and feasibility of implementing 103 ADHD treatment statements from sources including the UK NICE ADHD guidelines and US medication management algorithms.

RESULTS

Certain recommendations for ADHD medication management were judged as important and feasible to implement, including a stepwise titration of stimulant medication. Other recommendations were perceived as important but not feasible to implement in routine practice, such as weekly clinic follow-up with the family during titration and collection of follow-up symptom questionnaires.

CONCLUSIONS

Many of the key guideline recommendations for ADHD medication management are viewed by clinicians as important and feasible to implement. However, some recommendations present significant implementation challenges within the context of routine NHS clinical care in England.

DECLARATION OF INTEREST

C.H. and K.S. were members of the Guideline Development Group for the NICE ADHD Clinical Guideline (NICE CG78).

COPYRIGHT AND USAGE

© 2016 The Royal College of Psychiatrists. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence.

Brain structural deficits and working memory fMRI dysfunction in young adults who were diagnosed with ADHD in adolescence

When adolescents with ADHD enter adulthood, some no longer meet disorder diagnostic criteria but it is unknown if biological and cognitive abnorma lities persist. We tested the hypothesis that people diagnosed with ADHD during adolescence present residual brain abnormalities both in brain structure and in working memory brain function. 83 young adults (aged 20-24 years) from the Northern Finland 1986 Birth Cohort were classified as diagnosed with ADHD in adolescence (adolescence ADHD, n = 49) or a control group (n = 34). Only one patient had received medication for ADHD. T1-weighted brain scans were acquired and processed in a voxel-based analysis using permutation-based statistics. A sub-sample of both groups (ADHD, n = 21; controls n = 23) also performed a Sternberg working memory task whilst acquiring fMRI data. Areas of structural difference were used as a region of interest to evaluate the implications that structural abnormalities found in the ADHD group might have on working memory function. There was lower grey matter volume bilaterally in adolescence ADHD participants in the caudate (p < 0.05 FWE corrected across the whole brain) at age 20-24. Working memory was poorer in adolescence ADHD participants, with associated failure to show normal load-dependent caudate activation. Young adults diagnosed with ADHD in adolescence have structural and functional deficits in the caudate associated with abnormal working memory function. These findings are not secondary to stimulant treatment, and emphasise the importance of taking a wider perspective on ADHD outcomes than simply whether or not a particular patient meets diagnostic criteria at any given point in time.

Perceptual abnormalities related to sensory gating deficit are core symptoms in adults with ADHD

This study investigated and compared perceptual abnormalities related to sensory gating deficit in adult patients with Attention Deficit Disorder with Hyperactivity (A-ADHD) and adult patients with schizophrenia. Subjects were evaluated with the Sensory Gating Inventory (SGI). We compared SGI scores between patients with A-ADHD, patients with schizophrenia and healthy subjects. We also assessed the relationship between SGI scores and clinical symptoms, and evaluated the ability of the SGI to detect perceptual abnormalities in A-ADHD. Seventy adult patients with ADHD reported higher SGI scores than the 70 healthy subjects and the 70 patients with schizophrenia. The inattention factor of the ASRS correlated significantly with the overall SGI score. The ROC AUC for the overall SGI score in the A-ADHD group (versus the healthy group) illustrated good performance. The findings suggest that i) perceptual abnormalities are core symptoms of adult patients with ADHD and ii) the attention of patients with A-ADHD may be involuntarily drowned by many irrelevant environmental stimuli leading to their impaired attention on relevant stimuli. They also confirm that the SGI could be a useful self-report instrument to diagnose the clinical features of A-ADHD.

Establishing the Attention-Distractibility Trait

Failures to focus attention will affect any task engagement (e.g., at work, in the classroom, when driving). At the clinical end, distractibility is a diagnostic criterion of attention-deficit/hyperactivity disorder (ADHD). In this study, we examined whether the inability to maintain attentional focus varies in the overall population in the form of an attention-distractibility trait. To test this idea, we administered an ADHD diagnostic tool to a sample of healthy participants and assessed the relationship between ADHD symptoms and task distraction. ADHD symptom summary scores were significantly positively associated with distractor interference in letter-search and name-classification tasks (as measured by reaction time), as long as the distractors were irrelevant (cartoon images) rather than relevant (i.e., compatible or incompatible with target names). Higher perceptual load during a task eliminated distraction irrespective of ADHD score. These findings suggest the existence of an attention-distractibility trait that confers vulnerability to irrelevant distraction, which can be remedied by increasing the level of perceptual load during the task.

Validation of DSM-5 age-of-onset criterion of attention deficit/hyperactivity disorder (ADHD) in adults: Comparison of life quality, functional impairment, and family function

The newly published Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) elevates the threshold of the ADHD age-of-onset criterion from 7 to 12 years. This study evaluated the quality of life and functional impairment of adults with ADHD who had symptoms onset by or after 7 years and examined the mediation effect of family function and anxiety/depression symptoms between ADHD diagnosis and quality of life and functional impairment. We assessed 189 adults with ADHD and 153 non-ADHD controls by psychiatric interview and self-administered reports on the Adult ADHD Quality of Life Scale, Weiss Functional Impairment Rating Scale, Family APGAR, and Adult Self Report Inventory-4. The ADHD group was divided into early-onset ADHD (onset <7 years, n=147) and late-onset ADHD (onset between 7 and 12 years, n=42). The mediation analysis was conducted to verify the mediating factors from ADHD to functional impairment and quality of life. The late-onset ADHD had more severe functional impairment at work and poorer family support than early-onset ADHD while they had comparable impairment at other domains. Less perceived family support and current anxiety/depressive symptoms partially mediated the link between ADHD diagnosis and quality of life/functional impairment both in early- and late-onset ADHD. Our data support decreased quality of life and increased functional impairment in adult ADHD, regardless of age of onset, and these adverse outcomes may be mediated by family support and anxiety/depression at adulthood. Our findings also imply that the new DSM-5 ADHD criteria do not over-include individuals without impairment.

Atomoxetine treatment in adults with attention-deficit/hyperactivity disorder

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a CNS disorder that has its onset in childhood, but often persists into adulthood. There is growing recognition that adult ADHD can result in multiple negative consequences for individuals. ADHD is also often associated with a number of comorbid psychiatric disorders. Atomoxetine (ATX), a nonstimulant, selective noradrenergic reuptake inhibitor, was approved in the United States in 2002 for the treatment of ADHD in children and adolescents, as well as adults. We review here the safety and efficacy of ATX in adults with ADHD, including data in special populations, functional outcomes, as well as provider and patient real-world perceptions.

METHODS

We searched the databases Embase, MEDLINE and PsycINFO using the terms 'ADHD' and 'adult' and 'ATX' capturing publications from January 1, 1998, to March 27, 2014. Only publications in English were considered.

RESULTS

ATX demonstrated significantly greater improvement than placebo (PBO) on the Conners Adult ADHD Rating Scale-Investigator rated:Screening Version (CAARS-Inv:SV) in all trials (N = 6; total score difference ranged from -3.5 to -5.5). For long-term trials using the CAARS-Inv:SV, ATX demonstrated significantly greater improvement than PBO in three of four trials (total score differences ranged from -0.1 to -6.0). In short-term studies, ATX showed significantly greater improvement than PBO on the Adult ADHD Quality-of-Life scale total score in three of three studies, but results were mixed on the Sheehan Disability Scale. Three studies of ATX have reported statistically significant improvement (compared with PBO) on the Behavior Rating Inventory of Executive Function-Adult Version Self Report scale. The most common adverse events (occurring in ≥ 10% of patients taking ATX) were nausea, dry mouth, decreased appetite, insomnia and fatigue.

CONCLUSIONS

ATX is an important treatment option for the right patient. ATX can provide long-term, consistent symptom relief and functional improvement for adults with ADHD.

Social Network Analysis Reveals the Negative Effects of Attention-Deficit/Hyperactivity Disorder (ADHD) Symptoms on Friend-Based Student Networks

Introduction

Social network analysis has emerged as a promising tool in modern social psychology. This method can be used to examine friend-based social relationships in terms of network theory, with nodes representing individual students and ties representing relationships between students (e.g., friendships and kinships). Using social network analysis, we investigated whether greater severity of ADHD symptoms is correlated with weaker peer relationships among elementary school students.

Methods

A total of 562 sixth-graders from two elementary schools (300 males) provided the names of their best friends (maximum 10 names). Their teachers rated each student’s ADHD symptoms using an ADHD rating scale.

Results

The results showed that 10.2% of the students were at high risk for ADHD. Significant group differences were observed between the high-risk students and other students in two of the three network parameters (degree, centrality and closeness) used to assess friendship quality, with the high-risk group showing significantly lower values of degree and closeness compared to the other students. Moreover, negative correlations were found between the ADHD rating and two social network analysis parameters.

Conclusion

Our findings suggest that the severity of ADHD symptoms is strongly correlated with the quality of social and interpersonal relationships in students with ADHD symptoms.

The effects of physical exercise in children with attention deficit hyperactivity disorder: a systematic review and meta-analysis of randomized control trials

OBJECTIVE

The aim of this systematic review and meta-analysis was to examine the evidence for the effectiveness of exercise interventions on attention deficit hyperactivity disorder (ADHD)-related symptoms such as inattention, hyperactivity/impulsivity, anxiety and cognitive functions in children and adolescents.

METHOD

Five databases covering the period up to November 2014 (PubMed, Scopus, EMBASE, EBSCO [E-journal, CINAHL, SportDiscus] and The Cochrane Library) were searched. Methodological quality was assessed using the Cochrane tool of bias. Standardized mean differences (SMD) and 95% confidence intervals were calculated, and the heterogeneity of the studies was estimated using Cochran's Q-statistic.

RESULTS

Eight randomized controlled trials (n = 249) satisfied the inclusion criteria. The studies were grouped according to the intervention programme: aerobic and yoga exercise. The meta-analysis suggests that aerobic exercise had a moderate to large effect on core symptoms such as attention (SMD = 0.84), hyperactivity (SMD = 0.56) and impulsivity (SMD = 0.56) and related symptoms such as anxiety (SMD = 0.66), executive function (SMD = 0.58) and social disorders (SMD = 0.59) in children with ADHD. Yoga exercise suggests an improvement in the core symptoms of ADHD.

CONCLUSIONS

The main cumulative evidence indicates that short-term aerobic exercise, based on several aerobic intervention formats, seems to be effective for mitigating symptoms such as attention, hyperactivity, impulsivity, anxiety, executive function and social disorders in children with ADHD.

Liberal alcohol legislation: does it amplify the effects among Swiss men of person-related risk factors on heavy alcohol use?

AIM

To estimate the statistical interactions between alcohol policy strength and the person-related risk factors of sensation-seeking, antisocial personality disorder and attention-deficit/hyperactivity disorder related to heavy alcohol use.

DESIGN

Cross-sectional survey.

SETTING

Young Swiss men living within 21 jurisdictions across Switzerland.

PARTICIPANTS

A total of 5701 Swiss men (mean age 20 years) participating in the Cohort Study on Substance Use Risk Factors (C-SURF).

MEASUREMENTS

Outcome measures were alcohol use disorder (AUD) as defined in the DSM-5 and risky single-occasion drinking (RSOD). Independent variables were sensation-seeking, antisocial personality disorder (ASPD), attention-deficit/hyperactivity disorder (ADHD) and an index of alcohol policy strength.

FINDINGS

Alcohol policy strength was protective against RSOD [odds ratio (OR) = 0.91 (0.84-0.99)], while sensation-seeking and ASPD were risk factors for both RSOD [OR = 1.90 (1.77-2.04); OR = 1.69 (1.44-1.97)] and AUD [OR = 1.58 (1.47-1.71); OR = 2.69 (2.30-3.14)] and ADHD was a risk factor for AUD [OR = 1.08 (1.06-1.10)]. Significant interactions between alcohol policy strength and sensation-seeking were identified for RSOD [OR = 1.06 (1.01-1.12)] and AUD [OR = 1.06 (1.01-1.12)], as well as between alcohol policy strength and ASPD for both RSOD [OR = 1.17 (1.03-1.31)] and AUD [OR = 1.15 (1.02-1.29)]. These interactions indicated that the protective effects of alcohol policy strength on RSOD and AUD were lost in men with high levels of sensation-seeking or an ASPD. No interactions were detected between alcohol policy strength and ADHD.

CONCLUSION

Stronger alcohol legislation protects against heavy alcohol use in young Swiss men, but this protective effect is lost in individuals with high levels of sensation-seeking or having an antisocial personality disorder.

Prevalence of ADHD in nonpsychotic adult psychiatric care (ADPSYC): A multinational cross-sectional study in Europe

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) often persists into adulthood. This study was designed to estimate the prevalence of ADHD in adult psychiatric outpatients in several European countries.

METHOD

ADHD diagnosis was made using the Diagnostic Interview for ADHD in Adults, version 2.0 (DIVA), according to criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR) and 5th Edition (DSM-5).

RESULTS

Of 5662 patients present/approached, 2284 (40.3 %) consented, of whom 1986 patients (87.0 %) completed the study. Based on the DIVA, and applying DSM-IV-TR or DSM-5 criteria, 15.8 % (95 % confidence interval [CI] 14.2 %-17.4 %) or 17.4 % (95 % CI 15.7 %-19.0 %) of patients were diagnosed with ADHD, respectively. The prevalence of ADHD was 15.3 % when counting as non-ADHD those patients who screened positive but did not complete the DIVA (DSM-5).

CONCLUSIONS

Estimates from this study indicate that a relevant part of the psychiatric outpatient care population suffers from ADHD.

Physical activity intervention (Movi-Kids) on improving academic achievement and adiposity in preschoolers with or without attention deficit hyperactivity disorder: study protocol for a randomized controlled trial

BACKGROUND

The prevention of obesity and improvement of academic achievement in children are concerns of industrialized societies. Obesity has been associated with psychological disorders, including attention deficit hyperactivity disorder, whose prevalence has been estimated at 6.8 % in Spanish children and adolescents. It is known that physical activity is positively related to academic achievement and negatively related to the risk of obesity in children. However, studies to test the effectiveness of physical activity interventions in improving academic achievement in preschool children are scarce and have some weaknesses that threaten their validity. Moreover, very few studies have examined their effectiveness in improving symptoms of attention deficit hyperactivity disorder. This paper outlines a two-year multidimensional preschool intervention (Movi-Kids) aimed at preventing obesity and improving academic achievement in children with or without attention deficit hyperactivity disorder.

METHODS/DESIGN

Twenty-one schools from Ciudad Real and Cuenca, Spain, were randomized to intervention and control groups. In the first academic year, children in the third grade of preschool and the first grade of primary school in the intervention group received the Movi-Kids intervention. In the second academic year, schools were crossed over to the other group. The intervention included children, parents and teachers, and the school environment, and consisted of: (i) three hour-long sessions of recreational non-competitive physical activity after school, weekly, (ii) educational materials for parents and teachers addressing sedentary lifestyle risks and (iii) playground modifications to promote physical activity during breaks. Primary outcome measures of this study were academic achievement (intelligence, cognition, memory, attention and perception), assessed by the Battery of General and Differential Aptitudes, and adiposity measures (body mass index, waist circumference, triceps skinfold thickness and body fat percentage). Secondary outcome measures were: attention deficit hyperactivity disorder risk, motor skills, health-related quality of life and sleep quality. These variables will all be measured in both groups at baseline and at the end of the first and second academic years.

DISCUSSION

It seems reasonable that an intervention to promote physical activity based on playground games will be useful for simultaneously improving academic achievement and controlling obesity.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01971827 .

Adult attention deficit hyperactivity symptoms and psychosis: Epidemiological evidence from a population survey in England

Despite both having some shared features, evidence linking psychosis and adult attention deficit hyperactivity disorder (ADHD) is sparse and inconsistent. Hypotheses tested were (1) adult ADHD symptoms are associated with auditory hallucinations, paranoid ideation and psychosis (2) links between ADHD symptoms and psychosis are mediated by prescribed ADHD medications, use of illicit drugs, and dysphoric mood. The Adult Psychiatric Morbidity Survey 2007 (N=7403) provided data for regression and multiple mediation analyses. ADHD symptoms were coded from the ADHD Self-Report Scale (ASRS). Higher ASRS total score was significantly associated with psychosis, paranoid ideation and auditory hallucinations despite controlling for socio-demographic variables, verbal IQ, autism spectrum disorder traits, childhood conduct problems, hypomanic and dysphoric mood. An ASRS score indicating probable ADHD diagnosis was also significantly associated with psychosis. The link between higher ADHD symptoms and psychosis, paranoia and auditory hallucinations was significantly mediated by dysphoric mood, but not by use of amphetamine, cocaine or cannabis. In conclusion, higher levels of adult ADHD symptoms and psychosis are linked and dysphoric mood may form part of the mechanism. Our analyses contradict the traditional clinical view that the main explanation for people with ADHD symptoms developing psychosis is illicit drugs.

Prevalence and incidence of attention-deficit/hyperactivity disorder in Slovenian children and adolescents: a database study from a national perspective

AIM

To estimate prevalence and incidence of attention deficit hyperactivity disorder (ADHD) in children and adolescents in Slovenia using different epidemiological models.

METHODS

Data from the National Institute of Public Health of the Republic of Slovenia for the period 1997-2012 were analyzed. The database includes the annual number of newly diagnosed outpatients with ADHD in Slovenia. The evaluation for ADHD diagnoses was done in accordance with the Tenth Revision of the International Classification of Diseases (ICD-10) outpatient data codes. In model 1, a linear increase was proposed to fit the data in the period from 1997 to 2003 in order to extrapolate the data before 1997. In model 2 and 3, an exponential increase in the annual incidence rate was proposed.

RESULTS

The incidence rate of ADHD diagnosis in 1997 was 0.032% and in 2012 it increased to 0.082%. Mean prevalence rate was 750 (95% confidence interval: 660-840) per 100 000 children and adolescents. It was estimated that the prevalence rate in 2020 would be 1% (95% confidence interval: 0.875-1.125), which is 6.3-fold higher than in 1997.

CONCLUSIONS

ADHD is a common mental health disorder among Slovenian children and adolescents, but it remained underdiagnosed compared with Western countries. Our results indicated a need for improved timely interventions in Slovenia, not only in child and adolescent psychiatry but also in primary settings and adult psychiatry, where ADHD should be more efficiently recognized.

Locomotor activity measures in the diagnosis of attention deficit hyperactivity disorder: Meta-analyses and new findings

INTRODUCTION

Our aim was to assess differences in movement measures in attention-deficit/hyperactivity disorder (ADHD) vs. typically developing (TD) controls.

METHODS

We performed meta-analyses of published studies on motion measures contrasting ADHD with controls. We also conducted a case-control study with children/adolescents (n = 61 TD, n = 62 ADHD) and adults (n = 30 TD, n = 19 ADHD) using the McLean motion activity test, semi-structured diagnostic interviews and the behavior rating inventory of executive function and Conners (parent, teacher; self) rating scales.

RESULTS

Meta-analyses revealed medium-to-large effect sizes for actigraph (standardized mean difference [SMD]: 0.64, 95% confidence interval (CI): 0.43, 0.85) and motion tracking systems (SDM: 0.92, 95% CI: 0.65, 1.20) measures in differentiating individuals with ADHD from controls. Effects sizes were similar in studies of children/adolescents ([SMD]: 0.75, 95% CI: 0.50, 1.01) and of adults ([SMD]: 0.73, 95% CI: 0.46, 1.00). In our sample, ADHD groups differed significantly in number of head movements (p = 0.02 in children; p = 0.002 in adults), displacement (p = 0.009/p < 0.001), head area (p = 0.03/p < 0.001), spatial complexity (p = 0.06/p = 0.02) and temporal scaling (p = 0.05/p = 0.04). Mean effect sizes were non-significantly larger (d = 0.83, 95% CI: 0.20, 1.45) in adults vs. children/adolescents with ADHD (d = 0.45, 95% CI: 0.08, 0.82). In the concurrent go/no-go task, reaction time variability was significantly greater in ADHD (p < 0.05 in both age groups) than controls.

CONCLUSIONS

Locomotor hyperactivity remains core to the construct of ADHD even in adults. Our results suggest that objective locomotion measures may be particularly useful in evaluating adults with possible ADHD.

Emotional symptoms and their contribution to functional impairment in adults with attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a severe neurodevelopmental disorder beginning in childhood and consisting of the core symptoms of inattention, hyperactivity, and impulsivity. The disorder is often accompanied by functional impairment in daily life. Research showed that severe impairment cannot be fully explained by the core symptoms of ADHD. Accordingly, emotional symptoms in ADHD and their influence on functional impairment have increasingly become the focus of research in recent years. The aim of the current study was to investigate the relationship between ADHD core symptoms, emotional symptoms, and functional impairment. We assumed that emotional symptoms might form part of adult ADHD and that the connection between ADHD core symptoms and functional impairment may be partly mediated by emotional symptoms. Data of 176 participants from an ADHD Special Consultations Unit were included. Of these participants, 146 were diagnosed with ADHD, while 30 received no such diagnosis. We developed a structural equation model which included core symptoms, emotional symptoms, and four domains of daily impairment (family life, social life, work, and organization). As predicted, results indicate that emotional symptoms are directly linked to adult ADHD and bear a strong negative influence on different domains of daily life. The results of different analyses showed a mediation of the relationship between ADHD core symptoms and impairment through emotional symptoms: While the connection between inattention and work and organization was partly mediated, the connections between impulsivity and family life and between inattention and social life were shown to be fully mediated through emotional symptoms.

Attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a persistent neurodevelopmental disorder that affects 5% of children and adolescents and 2.5% of adults worldwide. Throughout an individual's lifetime, ADHD can increase the risk of other psychiatric disorders, educational and occupational failure, accidents, criminality, social disability and addictions. No single risk factor is necessary or sufficient to cause ADHD. In most cases ADHD arises from several genetic and environmental risk factors that each have a small individual effect and act together to increase susceptibility. The multifactorial causation of ADHD is consistent with the heterogeneity of the disorder, which is shown by its extensive psychiatric co-morbidity, its multiple domains of neurocognitive impairment and the wide range of structural and functional brain anomalies associated with it. The diagnosis of ADHD is reliable and valid when evaluated with standard criteria for psychiatric disorders. Rating scales and clinical interviews facilitate diagnosis and aid screening. The expression of symptoms varies as a function of patient developmental stage and social and academic contexts. Although there are no curative treatments for ADHD, evidenced-based treatments can markedly reduce its symptoms and associated impairments. For example, medications are efficacious and normally well tolerated, and various non-pharmacological approaches are also valuable. Ongoing clinical and neurobiological research holds the promise of advancing diagnostic and therapeutic approaches to ADHD. For an illustrated summary of this Primer, visit: http://go.nature.com/J6jiwl.

Transition to adult mental health services for young people with attention deficit hyperactivity disorder in Italy: Parents' and clinicians' experiences

OBJECTIVE

The aim of this study was to describe the experiences of parents and clinicians in relation to the transition from child and adolescent neuropsychiatric services (CANPS) to adult services for people with attention deficit hyperactivity disorder (ADHD) in Italy.

METHODS

Parents of people with ADHD who reached the transition boundary for CANPS were sampled from the A.I.F.A. association (Italian Association of ADHD Families). We thematically analyzed informative and qualitative questionnaires completed by parents and clinicians.

RESULTS

Parents' (n = 24) and clinicians' (n = 27) experiences differed slightly on challenges and unmet needs, whereas clinicians agreed on the variables required for an optimal transition process. Poor transition and multiple barriers to such care were identified. Specifically, far fewer people received services, especially public health services, after reaching the age of 18, and perceived barriers included problems with user access, limited transition protocols, poor service coordination, and possible lack of ADHD-related knowledge on the part of adult practitioners.

CONCLUSIONS

Care continuity in mental healthcare remains a need to be prioritized and better defined also for ADHD patients (and their parents). Parents' and clinicians' experiences are more likely to be positive if transition management is characterized by a gradual preparation, a period of parallel care, and commonly acknowledged, clear information on available services and how to access them. Identifying the needs and barriers of the people representing the different roles (clinicians, parents, and users) involved in the transition to adult mental health services is of particular importance in designing effective, shared transfer planning procedures.

The Speed of Visual Attention and Motor-Response Decisions in Adult Attention-Deficit/Hyperactivity Disorder

BACKGROUND

Adults with attention-deficit/hyperactivity disorder (ADHD) exhibit slowed reaction times (RTs) in various attention tasks. The exact origins of this slowing, however, have not been established. Potential candidates are early sensory processes mediating the deployment of focal attention, stimulus response translation processes deciding upon the appropriate motor response, and motor processes generating the response.

METHODS

We combined mental chronometry (RT) measures of adult ADHD (n = 15) and healthy control (n = 15) participants with their lateralized event-related potentials during the performance of a visual search task to differentiate potential sources of slowing at separable levels of processing: the posterior contralateral negativity (PCN) was used to index focal-attentional selection times, while the lateralized readiness potentials synchronized to stimulus and response events were used to index the times taken for response selection and production, respectively. To assess the clinical relevance of event-related potentials, a correlation analysis between neural measures and subjective current and retrospective ADHD symptom ratings was performed.

RESULTS

ADHD patients exhibited slower RTs than control participants, which were accompanied by prolonged PCN and lateralized readiness potentials synchronized to stimulus, but not lateralized readiness potentials synchronized to response events, latencies. Moreover, the PCN timing was positively correlated with ADHD symptom ratings.

CONCLUSIONS

The behavioral RT slowing of adult ADHD patients was based on a summation of internal processing delays arising at perceptual and response selection stages; motor response production, by contrast, was not impaired. The correlation between PCN times and ADHD symptom ratings suggests that this brain signal may serve as a potential candidate for a neurocognitive endophenotype of ADHD.

Systematic review of the epidemiology of attention deficit hyperactivity disorder in Arab countries

Objective:

To assess the epidemiology of attention deficit hyperactivity disorder (ADHD) in Arab countries, and identify gaps for future research.

Methods:

We searched PubMed from July 1978 to July 2014 and reviewed local journals with cross-referencing. The keywords we used were ADHD, diagnosis, prevalence, incidence, factor, diagnosis, rate, risk, and each of the names of the 22 Arab countries (Jordan, Egypt, Lebanon, Saudi Arabia, and so on). Studies were eligible for inclusion if they investigated the epidemiology of ADHD in any Arab country, and were published in English. The search was conducted from 2nd to 5th August 2014 in King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.

Results:

A total of 22 articles were included in the review. Twenty studies were cross-sectional and found the prevalence of ADHD ranged between 1.3-16%, prevalence of hyperactive type ADHD between 1.4-7.8%, and the prevalence of inattention type between 2.1-2.7%. Only 2 case-control studies investigated potential risk factors. Evidence extracted from these studies shows a significant association between ADHD and male gender, previous psychiatric illness in the family, vitamin D deficiency, poor school performance, sleep problems, and nocturnal enuresis.

Conclusion:

The prevalence of ADHD in Arab countries is comparable to reports in North America, Africa, and other countries of the Middle East. Longitudinal studies are needed to investigate the prognosis and determinants of this condition in the Arab world.

Comparison of pregnancy and lactation labeling for attention-deficit hyperactivity disorder drugs marketed in Australia, the USA, Denmark, and the UK

BACKGROUND

Pregnancy and lactation labeling is presented in the officially recognized product information (PI) accompanying prescription drugs to ensure appropriate prescribing in pregnant and breastfeeding women.

OBJECTIVE

The aim of this study was to analyze pregnancy and lactation labeling in PI for attention-deficit hyperactivity disorder drugs marketed across countries and to compare this information with respect to consistency and discrepancy.

METHODS

We manually surveyed PI for atomoxetine, methylphenidate, and modafinil marketed by the same pharmaceutical companies in Australia, the USA, Denmark, and the UK. We extracted information regarding data sources (animal and human data), risk to the fetus or breastfed child, excretion in breast milk, and recommendations for use. The extracted information was then analyzed and compared with respect to consistency and discrepancy.

RESULTS

Inter-country discrepancies were identified with respect to both animal and human data sources presented, types of risks listed in association with exposure during pregnancy and lactation, information regarding excretion of the drug in breast milk, and recommendations for use. Consistency was identified between PI for drugs marketed in the EU.

CONCLUSION

The study suggests that pregnancy and lactation labeling in PI for drugs marketed by the same pharmaceutical companies depend on the country of marketing; this raises concern about the reliability of PI documents as a useful source of information for appropriate prescribing during pregnancy and lactation. Discrepancies in this information can potentially lead to inappropriate prescribing in pregnant and breastfeeding women, who may expose their fetuses and breastfed children to unnecessary risks. At the same time, unjustified warnings against breastfeeding may result in children being unnecessarily weaned from being breastfed.

Sex differences in white matter integrity in youths with attention-deficit/hyperactivity disorder: a pilot study

Widespread disparities in white matter (WM) microstructure and organization have been found in adolescents with attention-deficit/hyperactivity disorder (ADHD); however, little is known about the role sex plays in these differences. The present diffusion tensor imaging (DTI) study performed whole-brain, tract-based, voxel-wise, and region of interest (ROI) analyses to investigate WM microstructure differences between ADHD and healthy control (HC) adolescents to examine the impact of sex on measures of fractional anisotropy (FA). Eighteen adolescents with ADHD and 24 HC were included in this study. All participants received a 64-direction DTI scan on a 3 Tesla Siemens scanner. FSL's TBSS was used to perform whole-brain, tract-based, voxel-wise analyses. Tracts demonstrating significant sex-by-diagnosis interactions were further evaluated using univariate analyses performed on mean FA data that were extracted from ROIs using the Johns Hopkins University WM tractography atlas. TBSS analyses between diagnostic groups revealed significantly increased FA in HC relative to ADHD in the bilateral superior longitudinal fasciculus (SLF), forceps major, left cingulum, and bilateral callosal regions. In addition, both TBSS and separate ROI analyses revealed significant sex-by-diagnosis interactions for the corticospinal tract (CST), inferior longitudinal fasciculus (ILF) and SLF. In the HC group, FA was increased in males relative to females for all analyses. In WM regions demonstrating a significant sex-by-diagnosis, FA was increased in females relative to males in the ADHD group. Our findings suggest that WM microstructure in several major WM tracts differs between males and females with ADHD. These differences in WM microstructure may account for some of the differences in ADHD subtypes and comorbidities seen between the sexes. Additional studies in ADHD, examining sex differences in phenotypic expression, treatment response and brain network trajectories are warranted.

Impulsivity in borderline personality disorder

BACKGROUND

Impulsivity is a core feature of borderline personality disorder (BPD) and is most frequently measured using self-rating scales. There is a need to find objective, valid and reliable measures of impulsivity. This study aimed to examine performance of participants with BPD compared with healthy controls on delay and probabilistic discounting tasks and the stop-signal task (SST), which are objective measures of choice and motor impulsivity, respectively.

METHOD

A total of 20 participants with BPD and 21 healthy control participants completed delay and probabilistic discounting tasks and the SST. They also completed the Barratt Impulsiveness Scale (BIS), a self-rating measure of impulsivity.

RESULTS

Participants with BPD showed significantly greater delay discounting than controls, manifest as a greater tendency to accept the immediately available lesser reward rather than waiting longer for a greater reward. Similarly they showed significantly greater discounting of rewards by the probability of payout, which correlated with past childhood trauma. Participants with BPD were found to choose the more certain and/or immediate rewards, irrespective of the value. On the SST the BPD and control groups did not differ significantly, demonstrating no difference in motor impulsivity. There was no significant difference between groups on self-reported impulsivity as measured by the BIS.

CONCLUSIONS

Measures of impulsivity show that while motor impulsivity was not significantly different in participants with BPD compared with controls, choice or reward-related impulsivity was significantly affected in those with BPD. This suggests that choice impulsivity but not motor impulsivity is a core feature of BPD.

Case-control genome-wide association study of persistent attention-deficit hyperactivity disorder identifies FBXO33 as a novel susceptibility gene for the disorder

Attention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder with high heritability. At least 30% of patients diagnosed in childhood continue to suffer from ADHD during adulthood and genetic risk factors may play an essential role in the persistence of the disorder throughout lifespan. To date, genome-wide association studies (GWAS) of ADHD have been completed in seven independent datasets, six of which were pediatric samples and one on persistent ADHD using a DNA-pooling strategy, but none of them reported genome-wide significant associations. In an attempt to unravel novel genes for the persistence of ADHD into adulthood, we conducted the first two-stage GWAS in adults with ADHD. The discovery sample included 607 ADHD cases and 584 controls. Top signals were subsequently tested for replication in three independent follow-up samples of 2104 ADHD patients and 1901 controls. None of the findings exceeded the genome-wide threshold for significance (PGC<5e-08), but we found evidence for the involvement of the FBXO33 (F-box only protein 33) gene in combined ADHD in the discovery sample (P=9.02e-07) and in the joint analysis of both stages (P=9.7e-03). Additional evidence for a FBXO33 role in ADHD was found through gene-wise and pathway enrichment analyses in our genomic study. Risk alleles were associated with lower FBXO33 expression in lymphoblastoid cell lines and with reduced frontal gray matter volume in a sample of 1300 adult subjects. Our findings point for the first time at the ubiquitination machinery as a new disease mechanism for adult ADHD and establish a rationale for searching for additional risk variants in ubiquitination-related genes.