Josep Antoni Ramos-Quiroga

European consensus statement on diagnosis and treatment of adult ADHD: The European Network Adult ADHD

BackgroundAttention deficit hyperactivity disorder (ADHD) is among the most common psychiatric disorders of childhood that persists into adulthood in the majority of cases. The evidence on persistence poses several difficulties for adult psychiatry considering the lack of expertise for diagnostic assessment, limited treatment options and patient facilities across Europe.MethodsThe European Network Adult ADHD, founded in 2003, aims to increase awareness of this disorder and improve knowledge and patient care for adults with ADHD across Europe. This Consensus Statement is one of the actions taken by the European Network Adult ADHD in order to support the clinician with research evidence and clinical experience from 18 European countries in which ADHD in adults is recognised and treated.ResultsBesides information on the genetics and neurobiology of ADHD, three major questions are addressed in this statement: (1) What is the clinical picture of ADHD in adults? (2) How can ADHD in adults be properly diagnosed? (3) How should ADHD in adults be effectively treated?ConclusionsADHD often presents as an impairing lifelong condition in adults, yet it is currently underdiagnosed and treated in many European countries, leading to ineffective treatment and higher costs of illness. Expertise in diagnostic assessment and treatment of ADHD in adults must increase in psychiatry. Instruments for screening and diagnosis of ADHD in adults are available and appropriate treatments exist, although more research is needed in this age group.

The genetics of attention deficit/hyperactivity disorder in adults, a review

The adult form of attention deficit/hyperactivity disorder (aADHD) has a prevalence of up to 5% and is the most severe long-term outcome of this common neurodevelopmental disorder. Family studies in clinical samples suggest an increased familial liability for aADHD compared with childhood ADHD (cADHD), whereas twin studies based on self-rated symptoms in adult population samples show moderate heritability estimates of 30–40%. However, using multiple sources of information, the heritability of clinically diagnosed aADHD and cADHD is very similar. Results of candidate gene as well as genome-wide molecular genetic studies in aADHD samples implicate some of the same genes involved in ADHD in children, although in some cases different alleles and different genes may be responsible for adult versus childhood ADHD. Linkage studies have been successful in identifying loci for aADHD and led to the identification of LPHN3 and CDH13 as novel genes associated with ADHD across the lifespan. In addition, studies of rare genetic variants have identified probable causative mutations for aADHD. Use of endophenotypes based on neuropsychology and neuroimaging, as well as next-generation genome analysis and improved statistical and bioinformatic analysis methods hold the promise of identifying additional genetic variants involved in disease etiology. Large, international collaborations have paved the way for well-powered studies. Progress in identifying aADHD risk genes may provide us with tools for the prediction of disease progression in the clinic and better treatment, and ultimately may help to prevent persistence of ADHD into adulthood.

Multicenter Analysis of the SLC6A3/DAT1 VNTR Haplotype in Persistent ADHD Suggests Differential Involvement of the Gene in Childhood and Persistent ADHD

Attention deficit/hyperactivity disorder (ADHD) is one of the most common neuropsychiatric disorders with a worldwide prevalence around 4–5% in children and 1–4% in adults. Although ADHD is highly heritable and familial risk may contribute most strongly to the persistent form of the disorder, there are few studies on the genetics of ADHD in adults. In this paper, we present the first results of the International Multicentre Persistent ADHD Genetics CollaboraTion (IMpACT) that has been set up with the goal of performing research into the genetics of persistent ADHD. In this study, we carried out a combined analysis as well as a meta-analysis of the association of the SLC6A3/DAT1 gene with persistent ADHD in 1440 patients and 1769 controls from IMpACT and an earlier report. DAT1, encoding the dopamine transporter, is one of the most frequently studied genes in ADHD, though results have been inconsistent. A variable number tandem repeat polymorphism (VNTR) in the 3′-untranslated region (UTR) of the gene and, more recently, a haplotype of this VNTR with another VNTR in intron 8 have been the target of most studies. Although the 10/10 genotype of the 3′-UTR VNTR and the 10-6 haplotype of the two VNTRs are thought to be risk factors for ADHD in children, we found the 9/9 genotype and the 9-6 haplotype associated with persistent ADHD. In conclusion, a differential association of DAT1 with ADHD in children and in adults might help explain the inconsistencies observed in earlier association studies. However, the data might also imply that DAT1 has a modulatory rather than causative role in ADHD.

Subcortical brain volume differences in participants with attention deficit hyperactivity disorder in children and adults: a cross-sectional mega-analysis

BACKGROUND Neuroimaging studies have shown structural alterations in several brain regions in children and adults with attention deficit hyperactivity disorder (ADHD). Through the formation of the international ENIGMA ADHD Working Group, we aimed to address weaknesses of previous imaging studies and meta-analyses, namely inadequate sample size and methodological heterogeneity. We aimed to investigate whether there are structural differences in children and adults with ADHD compared with those without this diagnosis. METHODS In this cross-sectional mega-analysis, we used the data from the international ENIGMA Working Group collaboration, which in the present analysis was frozen at Feb 8, 2015. Individual sites analysed structural T1-weighted MRI brain scans with harmonised protocols of individuals with ADHD compared with those who do not have this diagnosis. Our primary outcome was to assess case-control differences in subcortical structures and intracranial volume through pooling of all individual data from all cohorts in this collaboration. For this analysis, p values were significant at the false discovery rate corrected threshold of p=0·0156. FINDINGS Our sample comprised 1713 participants with ADHD and 1529 controls from 23 sites with a median age of 14 years (range 4-63 years). The volumes of the accumbens (Cohens d=-0·15), amygdala (d=-0·19), caudate (d=-0·11), hippocampus (d=-0·11), putamen (d=-0·14), and intracranial volume (d=-0·10) were smaller in individuals with ADHD compared with controls in the mega-analysis. There was no difference in volume size in the pallidum (p=0·95) and thalamus (p=0·39) between people with ADHD and controls. Exploratory lifespan modelling suggested a delay of maturation and a delay of degeneration, as effect sizes were highest in most subgroups of children (<15 years) versus adults (>21 years): in the accumbens (Cohens d=-0·19 vs -0·10), amygdala (d=-0·18 vs -0·14), caudate (d=-0·13 vs -0·07), hippocampus (d=-0·12 vs -0·06), putamen (d=-0·18 vs -0·08), and intracranial volume (d=-0·14 vs 0·01). There was no difference between children and adults for the pallidum (p=0·79) or thalamus (p=0·89). Case-control differences in adults were non-significant (all p>0·03). Psychostimulant medication use (all p>0·15) or symptom scores (all p>0·02) did not influence results, nor did the presence of comorbid psychiatric disorders (all p>0·5). INTERPRETATION With the largest dataset to date, we add new knowledge about bilateral amygdala, accumbens, and hippocampus reductions in ADHD. We extend the brain maturation delay theory for ADHD to include subcortical structures and refute medication effects on brain volume suggested by earlier meta-analyses. Lifespan analyses suggest that, in the absence of well powered longitudinal studies, the ENIGMA cross-sectional sample across six decades of ages provides a means to generate hypotheses about lifespan trajectories in brain phenotypes. FUNDING National Institutes of Health.

Efficacy of methylphenidate for adults with attention-deficit hyperactivity disorder: a meta-regression analysis.

Background: The efficacy of methylphenidate for adults with attention-deficit hyperactivity disorder (ADHD) shows wide between-study variability, which yields heterogeneous results in meta-analysis. The reasons for this variability have not been comprehensively investigated.Objectives: To determine the influence of treatment-related covariates of methylphenidate for adults with ADHD by means of meta-analysis. Clinical and methodological moderators and clinical trial reporting quality were also collected to control for their potential confounding effect.Methods: We searched for randomized, placebo-controlled clinical trials investigating the efficacy of methylphenidate for adults with ADHD. The study outcome was the efficacy of methylphenidate for reducing ADHD symptom severity. Treatment-related covariates included dose, type of drug-release formulation (formulations with a continuous drug release vs those with a non-continuous drug release), dose regimen (fixed vs flexible) and treatment length. Clinical (presence of co-morbid substance use disorders [SUD]) and methodological (design and rater) covariates were also collected, in addition to clinical trial reporting quality. The standardized mean difference (SMD) was calculated for each study. The analysis of the influence of methylphenidate effect modifiers was performed by means of random-effects meta-regression.Results: Eighteen studies were included. Dose, type of formulation and SUD appeared to modify the efficacy of methylphenidate in the bivariate analysis. These variables were included in a multivariate meta-regression, which showed that methylphenidate, at an average dose of 57.4 mg/day, delivered by means of non-continuous-release formulations, had a moderate effect on ADHD symptoms compared with placebo (SMD 0.57–0.58). A dose-response relationship was found, indicating that efficacy could be increased by SMD 0.11–0.12 for every 10 mg increment of methylphenidate. Continuous-release formulations and co-morbid SUD appeared to reduce the efficacy of methylphenidate. Nevertheless, the effect of treatment formulation may have been confounded by co-morbid SUD, since all studies using this continuous-release formulation were conducted in dual ADHD-SUD patients. No residual heterogeneity was found.Conclusions: This study shows that methylphenidate improves ADHD symptoms in adults in a dose-dependent fashion. The efficacy of methylphenidate appears to be reduced in patients with co-morbid SUD. It is unclear whether methylphenidate efficacy is influenced by the type of formulation, because the effect of this covariate is confounded by that of co-morbid SUD.

Association Study of 10 Genes Encoding Neurotrophic Factors and Their Receptors in Adult and Child Attention-Deficit/Hyperactivity Disorder

BACKGROUND Attention-deficit/hyperactivity disorder (ADHD) is a common childhood-onset psychiatric disorder that often persists into adolescence and adulthood and is characterized by inappropriate levels of inattention, hyperactivity, and/or impulsivity. Genetic and environmental factors are believed to be involved in the continuity of the disorder as well as in changes in ADHD symptomatology throughout life. Neurotrophic factors (NTFs), which participate in neuronal survival and synaptic efficiency, are strong candidates to contribute to the neuroplasticity changes that take place in the human central nervous system during childhood, adolescence, and early adulthood and might be involved in the genetic predisposition to ADHD. METHODS We performed a population-based association study in 546 ADHD patients (216 adults and 330 children) and 546 gender-matched unrelated control subjects with 183 single nucleotide polymorphisms covering 10 candidate genes that encode four neurotrophins (NGF, BDNF, NTF3, and NTF4/5), a member of the cytokine family of NTFs (CNTF), and their receptors (NTRK1, NTRK2, NTRK3, NGFR, and CNTFR). RESULTS The single-marker and haplotype-based analyses provided evidence of association between CNTFR and both adulthood (p = .0077, odds ratio [OR] = 1.38) and childhood ADHD (p = 9.1e-04, OR = 1.40) and also suggested a childhood-specific contribution of NTF3 (p = 3.0e-04, OR = 1.48) and NTRK2 (p = .0084, OR = 1.52) to ADHD. CONCLUSIONS Our data suggest that variations in NTFs might be involved in the genetic susceptibility to ADHD, support the contribution of the CNTFR locus as a predisposition factor for the disorder, and suggest that NTF3 and NTRK2 might be involved in the molecular basis of the age-dependent changes in ADHD symptoms throughout life span.

The negative impact of attention-deficit/hyperactivity disorder on occupational health in adults and adolescents

PurposeTo review the negative effects of attention-deficit/hyperactivity disorder (ADHD) in adolescence and adulthood on work productivity and occupational health.MethodsA review of the MEDLINE database was carried out to identify direct and indirect effects of ADHD on work, employment and occupational health.ResultsADHD is associated with higher levels of unemployment versus controls. Adults with ADHD who are employed experience workplace impairment and reduced productivity, as well as behavioural issues such as irritability and low frustration tolerance. Adults with ADHD are also at increased risk of accidents, trauma and workplace injuries, particularly traffic accidents. Indirect effects of ADHD on occupational health include reduced educational achievement and increased rates of substance abuse and criminality. Overall, ADHD in adults has a substantial economic impact as a result of absenteeism and lost productivity. Psychoeducation, combined with stimulant medications if necessary, is recommended as first-line treatment for adults with ADHD. Limited data available suggest that stimulant treatment can improve work productivity and efficacy, and reduce the risks associated with driving, although further studies are necessary.ConclusionsADHD can affect the ability to gain and maintain employment and to work safely and productively. As ADHD is a treatable condition, patients, employers and physicians have a role to play in ensuring optimal occupational health.

COMORBID ATTENTION-DEFICIT/ HYPERACTIVITY DISORDER IN BORDERLINE PATIENTS DEFINES AN IMPULSIVE SUBTYPE OF BORDERLINE PERSONALITY DISORDER

In order to examine the impulsive profile of a BPD sample with comorbid ADHD, adult patients who met criteria for BPD were assessed for ADHD with the CAADID and the WURS. A high rate of ADHD in the BPD sample was found, with sixty-nine (38.1%) BPD patients diagnosed as having comorbid adult ADHD. BPD-ADHD group had higher rates of general substance use disorder (59.4% vs. 38.4%), antisocial personality disorder (7.2% vs. 0.9%) and obsessive-compulsive personality disorder (21.7% vs. 6.3%). The BPD group without comorbid adult ADHD showed a higher rate of mood disorders (62.5% vs. 37.7%), panic disorders (54.5% vs. 23.1%) and benzodiazepine abuse (18.8% vs. 5.8%). Only in BPD patients without ADHD was comorbid avoidant personality disorder found. BPD patients could be distinguished in two clear subgroups related to the adult ADHD comorbidity. BPD-ADHD patients showed a more homogeneous and impulsive profile while BPD without ADHD comorbidity had more anxiety and depressive disorders.

Effect of Switching Drug Formulations from Immediate-Release to Extended-Release OROS Methylphenidate

AbstractBackground: The potential advantages of osmotic-release oral system (OROS) methylphenidate (Concerta®) over immediate-release (IR) methylphenidate (Rubifen®) in adults with attention-deficit hyperactivity disorder (ADHD), with respect to medication adherence, effectiveness and tolerability, are yet to be determined. Objective: To compare the adherence, effectiveness and tolerability of OROS methylphenidate versus IR methylphenidate in adults with ADHD. It was hypothesized (after data collection) that adherence and effectiveness would be higher with OROS methylphenidate than with the IR formulation. Study design: A chart review was carried out from April 2004 until April 2005. Setting: Adult ADHD outpatient program in a general hospital in Spain. Patients: Seventy adults with ADHD who met DSM-IV-TR criteria and who did not have any other current major psychiatric disorder. Intervention: Patients were treated with IR methylphenidate three times daily for 3 months and then switched to OROS methylphenidate once daily. Main outcome measure: Effectiveness was assessed by means of the ADHD rating scale-IV (ADHD-RS-IV) and the Clinical Global Impression-Improvement (CGI-I) scale at 3 months (coinciding with treatment switch) and at 6 months. The Simplified Medication Adherence Questionnaire (SMAQ) was used to assess treatment adherence, and was administered at both 3 and 6 months. Results: Seventy adult ADHD patients (mean age ± SD: 30 ± 9.6 years; n = 48 men [68.6%]) were included in this study. The mean baseline ADHD-RS-IV score was 34.6 (SD = 10.9). The mean daily dose of IR methylphenidate was 52.1 mg (SD = 13.8 mg) administered as three divided doses. After the treatment switch, the mean OROS methylphenidate daily dose was 57.9 mg (SD = 16.5 mg) administered once daily.The switch from IR methylphenidate to OROS methylphenidate was associated with a statistically significant improvement in all items of the SMAQ questionnaire. OROS methylphenidate was more effective than IR methylphenidate (p = 0.0005) in reducing symptoms of ADHD. The percentage of responders was 28.6% with IR methylphenidate and 91.4% with the OROS formulation (p = 0.0005). OROS methylphenidate was preferred by 97% of patients. The most common adverse events for each formulation were dry mouth (30% IR methylphenidate) and mood instability (31% OROS methylphenidate). No patients stopped treatment with methylphenidate because of adverse events. Conclusions: The switch from IR to OROS methylphenidate was associated with an improvement in both adherence and effectiveness. There were no differences between IR and OROS methylphenidate in terms of tolerability.

Case-Control Study of Six Genes Asymmetrically Expressed in the Two Cerebral Hemispheres: Association of BAIAP2 with Attention-Deficit/Hyperactivity Disorder

BACKGROUND Attention-deficit/hyperactivity disorder (ADHD) is a childhood-onset neuropsychiatric disease that persists into adulthood in at least 30% of patients. There is evidence suggesting that abnormal left-right brain asymmetries in ADHD patients may be involved in a variety of ADHD-related cognitive processes, including sustained attention, working memory, response inhibition and planning. Although mechanisms underlying cerebral lateralization are unknown, left-right cortical asymmetry has been associated with transcriptional asymmetry at embryonic stages and several genes differentially expressed between hemispheres have been identified. METHODS We selected six functional candidate genes showing at least 1.9-fold differential expression between hemispheres (BAIAP2, DAPPER1, LMO4, NEUROD6, ATP2B3, and ID2) and performed a case-control association study in an initial Spanish sample of 587 ADHD patients (270 adults and 317 children) and 587 control subjects. RESULTS The single- and multiple-marker analysis provided evidence for a contribution of BAIAP2 to adulthood ADHD (p = .0026 and p = .0016, respectively). We thus tested BAIAP2 for replication in two independent adult samples from Germany (639 ADHD patients and 612 control subjects) and Norway (417 ADHD cases and 469 control subjects). While no significant results were observed in the Norwegian sample, we replicated the initial association between BAIAP2 and adulthood ADHD in the German population (p = .0062). CONCLUSIONS Our results support the participation of BAIAP2 in the continuity of ADHD across life span, at least in some of the populations analyzed, and suggest that genetic factors potentially influencing abnormal cerebral lateralization may be involved in this disorder.