Review article

Diagnosis and evaluation of adults with attention-deficit/hyperactivity disorder

ADHD is often described as a disorder of altered reward sensitivity, yet few studies have examined the extent to which: (i) treatments for ADHD impact reward-related mechanisms; and (ii) changes in the reward system are associated with clinical improvement. This study addresses these issues - examining the extent to which clinical improvement following lisdexamfetamine (LDX) treatment is associated with changes in brain reward system activation.

Twenty adults (M = 11, 55%, F = 9, 45%), ages 19–52 (M = 33.9, SD = 10.0) with ADHD participated in a randomized cross-over study with lisdexamfetamine (LDX) and placebo (PB). Changes in brain activation were assessed during functional magnetic resonance (fMRI) scans: after receiving 3–5 weeks of treatment with LDX and 3–5 weeks of no drug/PB. fMRI contrasts were derived from the passive-avoidance (PA) learning task, which assessed reward-related learning using computational variables. We analyzed the following conditions: the Choice-Phase, modulated by the expected value (EV; i.e., object-choose and object-reject), and the Feedback-Phase, modulated by the prediction error (PE; i.e., reward and punish). Clinical symptom severity was assessed via interview with the ADHD-Rating Scale (ADHD-RS-IV). To address the primary objective, we performed group-level mass-univariate regression analyses between LDX and PB of percent change of the ADHD-RS total scores and the four contrast images under the Choice- and Feedback-conditions. Significance was set at a whole-brain voxel-wise threshold of p < 0.05 with family-wise error (FWE) correction and an extent (cluster) threshold of 50 contiguous voxels.

Improvement in ADHD symptoms with LDX was accompanied by significantly increased activation in a series of brain regions previously implicated in reinforcement processing in the choice and feedback conditions (e.g., left caudate and putamen, right orbitofrontal cortex, left middle frontal, superior frontal, and precentral gyri).

These findings, while preliminary, are the first to show that ADHD symptom improvement with stimulant treatment is associated with increased responsiveness of brain systems engaged in reward processing. Results support the hypothesis that LDX treatment may restore balance to dysfunction (e.g., hypoactivation) within the brain reward circuitry in adults with ADHD.

Trial Registration Clinicaltrials.gov Identifier: NCT01924429.

Cognitive control has been strongly linked to midfrontal theta (4–8 Hz) brain activity. Such control processes are known to be impaired in individuals with psychiatric conditions and neurodevelopmental diagnoses, including attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Temporal variability in theta, in particular, has been associated with ADHD, with shared genetic variance underlying the relationship. Here, we investigated the phenotypic and genetic relationships between theta phase variability, theta-related signals (the N2, error-related negativity, and error positivity), reaction time, and ADHD and ASD longitudinally in a large twin study of young adults to investigate the stability of the genetic relationships between these measures over time.

Genetic multivariate liability threshold models were run on a longitudinal sample of 566 participants (283 twin pairs). Characteristics of ADHD and ASD were measured in childhood and young adulthood, while an electroencephalogram was recorded in young adulthood during an arrow flanker task.

Cross-trial theta phase variability in adulthood showed large positive phenotypic and genetic relationships with reaction time variability and both childhood and adult ADHD characteristics. Error positivity amplitude was negatively related phenotypically and genetically to ADHD and ASD at both time points.

We showed significant genetic associations between variability in theta signaling and ADHD. A novel finding from the current study is that these relationships were stable across time, indicating a core dysregulation of the temporal coordination of control processes in ADHD that persists in individuals with childhood symptoms. Error processing, indexed by the error positivity, was altered in both ADHD and ASD, with a strong genetic contribution.

Vitamin D deficiency is believed to affect between 35 and 55% of the world's population, making it a hidden pandemic. In addition to its role in bone and calcium homeostasis, vitamin D has also been linked in preclinical and clinical research to brain function. These outcomes have also been used for a variety of neuropsychiatric and neurodevelopmental problems. Nevertheless, these individuals are more prone to develop signs of cognitive decline. This review will emphasize the association between vitamin D and neuropsychiatric illnesses such as autism, schizophrenia, depression, and Attention Deficit Hyperactivity Disorder (ADHD). While numerous research show vitamin D's essential role in cognitive function in neuropsychiatric illnesses, it is too early to propose its effect on cognitive symptoms with certainty. It is necessary to conduct additional research into the associations between vitamin D deficiency and cognitive abnormalities, particularly those found in autism, schizophrenia, depression, and ADHD, to develop initiatives that address the pressing need for novel and effective preventative therapeutic strategies.

Although high rates of poor adherence/persistence have been documented in ADHD, there is limited research targeting the problem. This systematic review evaluated interventions to address poor adherence/persistence to ADHD pharmacotherapy, with the aim of guiding the development of future interventions. An extensive search was conducted from January 1980 until January 2021. Thirteen studies were identified involving interventions based on psychoeducation, behavioural therapy, combined psychoeducation/behavioural therapy, technology-based interventions, written informed consent and a nursing support line. All 13 studies (including five RCTs) reported improvement in adherence/persistence and five studies (including four RCTs) also reported improvement in ADHD symptomatology. Almost all studies involved interventions utilising some form of education. Three RCTs of psychoeducation alone were included, with two of the three studies reporting adherence benefits at three and 12 months respectively. The third RCT was terminated early due to poor recruitment. A behavioural intervention RCT reported improved adherence six months post intervention (but not at 12 months), although a substantial drop-out rate was observed. A final included RCT used a Smartphone Application and reported a short term increase in adherence. The authors of the studies in this review make salient attempts at improving adherence and provide insight for future intervention development. We believe future interventions should involve combinations of strategies, have a theoretical framework and target the most common reasons for non-adherence. Interventions should also be integratable into routine care and include patient input to maximise sustainability.

Le trouble du déficit de l’attention avec ou sans hyperactivité (TDAH) de l’adulte est souvent associé aux troubles de l’usage de substances (TUS), qui ont alors un début précoce et un développement plus sévère, avec une efficacité moindre du traitement. Il n’existe pas de recommandation en langue française sur le repérage, le diagnostic et la prise en charge de ces situations de comorbidité.

Nous avons utilisé la méthode de Delphi modifiée et la revue de la littérature pour aboutir à une déclaration de consensus concernant le dépistage, le diagnostic et le traitement du TDAH chez les sujets souffrant de TUS.

Les outils de dépistage du TDAH sont utiles chez les adultes souffrant de TUS. Ils devraient être utilisés en routine en cas de TUS, mais être suivis d’une confirmation diagnostique du TDAH le plus rapidement possible. Un traitement simultané et intégré du TDAH et des TUS combinant psychothérapie et pharmacothérapie, est recommandé, incluant le méthylphénidate et les amphétamines dans leurs formes à libération prolongée, ainsi que l’atomoxétine. Des doses élevées peuvent être envisagées chez les patients ne répondant pas à la posologie usuelle.

des outils diagnostiques et thérapeutiques sont disponibles pour la prise en charge du TDAH en contexte de TUS. Les traitements pharmacologiques sont en cours d’autorisation finale en France. Chez les sujets souffrant de TDAH, des comorbidités psychiatriques et non-psychiatriques autres que le TUS sont très fréquentes, mais ne doivent pas retarder la prise en charge multimodale.

Attention deficit disorder with or without hyperactivity (ADHD) in adults is often associated with substance use disorders (SUD), which have an early onset and more severe development, with less effective treatment. There are no recommendations in French on the identification, diagnosis and management of these comorbid situations.

We used the modified Delphi method and literature review to arrive at a consensus statement regarding the screening, diagnosis and treatment of ADHD in subjects with SUD.

ADHD screening tools are useful in adults with SUD. They should be used routinely for SUD, but followed by diagnostic confirmation of ADHD as soon as possible. Simultaneous and integrated treatment of ADHD and SUD, combining psychotherapy and pharmacotherapy, is recommended, including methylphenidate and amphetamines in their extended-release forms, as well as atomoxetine. High doses may be considered for patients who do not respond to standard dosing.

Diagnostic and therapeutic tools are available for the management of ADHD in the context of SUD. Pharmacological treatments are in the process of final approval in France. In subjects with ADHD, psychiatric and non-psychiatric comorbidities other than SUD are common, but should not delay multimodal management.

We sought to elucidate the acute effects of high-intensity interval training (HIIT) among college students with and without attention-deficit/hyperactivity disorder (ADHD). Participants were age- and sex-matched across ADHD (n = 18) and non-ADHD groups (n = 18) and both groups completed baseline (non-HIIT) and experimental sessions (HIIT). We examined within- and between-subject effects on a continuous performance task (CPT) and self-reported ADHD and internalizing symptomatology. We found that the degree of improvement on ADHD and depressive symptomatology, as well as processing speed and response variability following HIIT was significantly greater for the ADHD group than the comparison group. Further investigations such as randomized controlled trials focusing on the chronic effects of sustained HIIT interventions are needed to substantiate the potential feasibility and efficacy of HIIT as an intervention. HIIT may be a useful adjunct to psychosocial and/or pharmacological treatments for college students with ADHD because it: (a) yields immediate, acute improvements in executive functioning, ADHD, and mood; (b) promotes improved physical and mental health; (c) poses a relatively low risk of deleterious effects in apparently healthy college students. Even with the need for additional research, current data suggest a single, brief, high-intensity bout of aerobic exercise can yield immediate significant short-term improvements. These improvements may enhance functioning and improve outcomes for college students with ADHD.