Treatment of adults with attention-deficit/hyperactivity disorder

Involvement of posterior hypothalamic CaMKII-positive neurons in ADHD-like behaviors in mice

This study explores the behavioral effects of modulating CaMKII-positive (CaMKII+) neurons in the posterior hypothalamus (PH). Utilizing a chemogenetic approach in mice, we discovered that the activation of CaMKII + neurons within the PH is associated with heightened locomotor activity, reduced social interaction, and impulsive behavior unrelated to anxiety or avoidance. These observed behaviors share a significant resemblance with characteristics commonly found in attention deficit and hyperactivity disorder (ADHD). Notably, treatment with clonidine, which is frequently prescribed for ADHD, effectively reduced impulsive behaviors in our mouse model. Our findings uncover the role of the PH that has not been previously explored and suggest a possible involvement of the PH in the manifestation of ADHD-like behaviors.

Current nonstimulant medications for adults with attention-deficit/hyperactivity disorder

INTRODUCTION

Stimulants, including methylphenidate and amphetamines, are the first-line pharmacological treatment of ADHD in adults. However, in patients who do not respond or poorly tolerate stimulants, non-stimulant medications are usually recommended.

AREAS COVERED

The authors provide a narrative review of the literature on non-stimulant treatments for adult ADHD, including controlled and observational clinical studies conducted on adult samples. Atomoxetine has been extensively studied and showed significant efficacy in treating adult ADHD. Issues related to dosing, treatment duration, safety, and use in the case of psychiatric comorbidity are summarized. Among other compounds indicated for ADHD in adults, antidepressants sharing at least a noradrenergic or dopaminergic component, including tricyclic compounds, bupropion, and viloxazine, have shown demonstratable efficacy. Evidence is also available for antihypertensives, particularly guanfacine, as well as memantine, metadoxine, and mood stabilizers, while negative findings have emerged for galantamine, antipsychotics, and cannabinoids.

EXPERT OPINION

While according to clinical guidelines, atomoxetine may serve as the only second-line option in adults with ADHD, several other nonstimulant compounds may be effectively used in order to personalize treatment based on comorbid conditions and ADHD features. Nevertheless, further research is needed to identify and test more personalized treatment strategies for adults with ADHD.

Assessment of centanafadine in adults with ADHD: a matching adjusted indirect comparison versus methylphenidate hydrochloride extended release (Concerta)

OBJECTIVE

To compare safety and efficacy of centanafadine versus methylphenidate hydrochloride extended release (ER; Concerta) in adults with ADHD.

METHODS

Without head-to-head trials, anchored matching-adjusted indirect comparisons (MAIC) of adverse event rates reported across trials and mean change from baseline in Adult ADHD Investigator Symptom Rating Scale (AISRS) score between centanafadine and methylphenidate hydrochloride ER were conducted. Pooled patient-level data from two centanafadine trials (NCT03605680/NCT03605836) and aggregate data from one published methylphenidate hydrochloride ER trial (NCT00937040) were used. Characteristics of individual patients from the centanafadine trials were matched to aggregate baseline characteristics from the methylphenidate hydrochloride ER trial using propensity score weighting. A sensitivity analysis assessed the robustness of the results to the capping of extreme weights (i.e. >99th percentile).

RESULTS

Compared with methylphenidate hydrochloride ER, centanafadine was associated with significantly lower risk of dry mouth (risk difference [RD] in percentage points: -11.95), initial insomnia (-11.10), decreased appetite (-8.05), anxiety (-5.39), palpitations (-5.25), and feeling jittery (-4.73) though a significantly smaller reduction in AISRS score (4.16-point). In the sensitivity analysis, the safety results were consistent with the primary analysis but there was no significant difference in efficacy between centanafadine and methylphenidate hydrochloride ER.

CONCLUSION

In this MAIC, centanafadine had better safety and possibly lower efficacy than methylphenidate hydrochloride ER. While safety results were robust across analyses, there was no efficacy difference between centanafadine and methylphenidate hydrochloride ER in the sensitivity analysis. Considering its favorable safety profile, centanafadine may be preferred among patients for whom treatment-related adverse events are a concern.

Correlation Between Life Satisfaction and Symptoms of ADHD in Dental Students: The Mediation of Resilience

OBJECTIVE

This study explores the correlation between life satisfaction and ADHD symptoms. It also discusses whether resilience mediates the correlation between ADHD symptoms and life satisfaction.

METHOD

We surveyed 297 dental students. A total of 291 completed a self-report scale consisting of the Adult ADHD Self-Report Scale, Wender Utah Rating Scale, Life Satisfaction Scale, and Conner-Davidson Resilience Scale. The study used hierarchical linear regression analysis, resampling, and asymptotic strategies for data processing.

RESULTS

The ADHD screening results of the self-report scale were positive for 6.87% of the students. This positive rate differed among participants of diverse ages and varying paternal education levels. ADHD symptoms were negatively correlated with life satisfaction and resilience. Life satisfaction was observably positively associated with resilience. Resilience serves as a mediating role between life satisfaction and the two symptoms of ADHD.

CONCLUSION

Resilience intervention programs can enhance the life satisfaction of dental students, especially those with positive ADHD symptoms screening.

Determining cutoff scores on the Conners' adult ADHD rating scales that can definitively rule out the presence of ADHD in a clinical sample

In recent years, the prevalence of Attention Deficit/Hyperactivity Disorder (ADHD) and the number of individuals seeking ADHD assessments has risen significantly, leading to an increased demand for accurate diagnostic tools. This study aimed to identify cutoff scores on the Conners' Adult ADHD Rating Scales (CAARS-S:L) that can definitively rule out the presence of ADHD. Among 102 clinically diagnosed adult ADHD participants and 448 non-ADHD participants who completed the CAARS-S:L, a receiver operating characteristic curve analysis established a perfectly discriminant cutoff T-score of <44 on the ADHD Symptoms Total subscale when looking at any ADHD diagnosis and <54 on the Inattentive Symptoms subscale when looking at individuals diagnosed with the inattentive subtype of ADHD. Alternative cutoffs of <54 (ADHD Symptoms Total subscale) and <63 (Inattentive Symptoms subscale) were also identified, both with a sensitivity of 0.95 or higher. Furthermore, the analysis found the ADHD Index to be a poor predictor of a negative ADHD diagnosis, suggesting against the use of this scale for cutoff determination. Despite this limitation, these findings indicate that with specific cutoffs, the CAARS-S:L may have the potential to conclusively rule out ADHD, effectively streamlining the diagnostic process and reducing unnecessary comprehensive assessments in clear negative cases.

Safety and Efficacy of Centanafadine Sustained-Release in Adults With Attention-Deficit Hyperactivity Disorder: Results of Phase 2 Studies

PURPOSE

Two phase 2 studies evaluated the efficacy and tolerability of centanafadine sustained-release (SR) for adults with attention-deficit/hyperactivity disorder (ADHD).

PATIENTS AND METHODS

In a phase 2a, flexible-dose, single-blind study, 41 male patients (aged 18‒55 years) with a diagnosis of ADHD (based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) were titrated with centanafadine-SR 200‒300, 400, or 500 mg/d for 2 weeks, and then were treated with the titrated dose for 2 weeks. In a phase 2b, randomized, double-blind, placebo-controlled, crossover study, 85 male and female patients (aged 18‒60 years) with a diagnosis of ADHD (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) were titrated to target doses of centanafadine-SR 400, 500, 600, or 800 mg/d over the course of 1 week, and then received their titrated dose for 3 weeks. The primary outcome in both studies was mean total ADHD Rating Scale-IV (ADHD-RS-IV) score.

RESULTS

In the phase 2a study, mean ADHD-RS-IV total score decreased by 21.41 (standard deviation 10.74) from the start of active centanafadine-SR treatment to the end of week 4 (P<0.001). In the phase 2b study, centanafadine-SR treatment resulted in a statistically significant improvement in ADHD-RS-IV from baseline to week 3 compared with placebo (least-squares mean -16.5 vs -8.4; P<0.001; effect size 0.66), with significant efficacy demonstrated as early as week 1. Centanafadine-SR was generally well tolerated at doses ≤400 mg. Most treatment-emergent adverse events (TEAEs) were mild or moderate; decreased appetite, headache, and nausea were the most frequently reported. In the 2 studies, 13 of 120 patients discontinued centanafadine-SR due to TEAEs; however, only 1 patient who received ≤400 mg discontinued due to a TEAE. No serious TEAEs were reported at any dose.

CONCLUSION

These results support the continued development of centanafadine-SR at doses up to 400 mg/d.

Diagnostic Accuracy of the Conners' Adult ADHD Rating Scale in a Postsecondary Population

Objective: Clinicians frequently rely upon the results of self-report rating scales when making the diagnosis of ADHD; however, little research exists regarding the ability of self-report measures to accurately differentiate ADHD from other disorders. Method: This present study investigated the ability of the Conners' Adult ADHD Rating Scale (CAARS) to discriminate between 249 postsecondary students with carefully diagnosed ADHD and 507 clinical controls. Results: The overall discriminant validity of the CAARS was 69%, and it had an unacceptably high false positive and false negative rate. At lower prevalence rates, a high score on the CAARS has only a 22% chance of accurately identifying individuals with ADHD. Conclusion: Although the CAARS is an adequate screening measure, it should not be the main method by which a diagnosis is made, as it frequently misidentifies individuals with other psychological complaints as having ADHD. Implications for clinical practice are discussed.

Associations of personality traits with internet addiction in Chinese medical students: the mediating role of attention-deficit/hyperactivity disorder symptoms

BACKGROUND

Internet addiction (IA) has emerged as a public health concern, particularly among adolescents and young adults. However, few studies have been conducted in medical students. This multi-center study aimed to investigate the prevalence of IA in Chinese medical students, to examine the associations of big five personality traits with IA in the population, and to explore the possible mediating role of attention-deficit/hyperactivity disorder (ADHD) symptoms in the relationship.

METHODS

Self-reported questionnaires, including Internet Addiction Test (IAT), Big Five Inventory (BFI), Adult ADHD Self-Report Scale-V1.1 (ASRS-V1.1) Screener, and socio-demographic section were distributed to clinical students at 3 medical schools in China. A total of 1264 students became the final subjects.

RESULTS

The overall prevalence of IA among Chinese medical students was 44.7% (IAT > 30), and 9.2% of the students demonstrated moderate or severe IA (IAT ≥ 50). After adjustment for covariates, while conscientiousness and agreeableness were negatively associated with IA, neuroticism was positively associated with it. ADHD symptoms mediated the associations of conscientiousness, agreeableness and neuroticism with IA.

CONCLUSION

The prevalence of IA among Chinese medical students is high. Both personality traits and ADHD symptoms should be considered when tailored intervention strategies are designed to prevent and reduce IA in medical students.

Increased arterial pressure in mice with overexpression of the ADHD candidate gene calcyon in forebrain

The link between blood pressure (BP) and cerebral function is well established. However, it is not clear whether a common mechanism could underlie the relationship between elevated BP and cognitive deficits. The expression of calcyon, a gene abundant in catecholaminergic and hypothalamic nuclei along with other forebrain regions, is increased in the brain of the spontaneously hypertensive rat (SHR) which is a widely accepted animal model of essential hypertension and attention deficit hyperactivity disorder (ADHD). Previous studies demonstrated that mice with up-regulation of calcyon in forebrain (CalOE) exhibit deficits in working memory. To date, there is no evidence directly connecting calcyon to BP regulation. Here, we investigated whether forebrain up-regulation of calcyon alters BP using radiotelemetry. We found that CalOE mice exhibited higher mean arterial pressure (MAP) compared to tTA controls. Plasma norepinephrine levels were significantly higher in CalOE mice compared to tTA controls. Silencing the transgene with doxycycline normalized BP in CalOE mice, whereas challenging the mice with 4% high salt diet for 12 days exacerbated the MAP differences between CalOE and tTA mice. High salt diet challenge also increased proteinuria and urinary thiobarbituric acid reactive substances (TBARs) in tTA and CalOE; and the increases were more prominent in CalOE mice. Taken together, our data suggest that upregulation of calcyon in forebrain could increase BP via alterations in noradrenergic transmission and increased oxidative stress during high salt challenge. Overall, this study reveals that calcyon could be a novel neural regulator of BP raising the possibility that it could play a role in the development of vascular abnormalities.

Associations between symptoms of attention-deficit/ hyperactivity disorder and life satisfaction in medical students: the mediating effect of resilience

BACKGROUND

Research on symptoms of attention-deficit/hyperactivity disorder (ADHD) in medical students is rather scant. Studying the disorder in this population, especially its associations with positive psychological constructs can further the understanding of mental health in future physicians. The objectives of the present study were to investigate the prevalence of ADHD symptoms in medical students, to examine the relationships between ADHD symptoms and life satisfaction, and to explore the mediating role of resilience on the associations.

METHODS

This cross-sectional study was carried out at one medical university in China, in June 2016. Self-reported questionnaires consisting of Adult ADHD Self-Report Scale (ASRS), Wender Utah Rating Scale (WURS), Conner-Davidson Resilience Scale (CD-RISC), Satisfaction With Life Scale (SWLS), and socio-demographic characteristics, were distributed to the students. Hierarchical linear regression analyses were used to examine the effects of ADHD symptoms on life satisfaction, and asymptotic and resampling strategies were used to explore the mediating role of resilience.

RESULTS

A total number of 521 medical students became final subjects. Based on the cutoffs of the scales, 1.54% of the medical students were highly likely to have ADHD, and 6.91% of the students were likely to have ADHD. Only inattention was negatively correlated with life satisfaction in the students. Resilience functioned as a mediator in the relationship between inattention and life satisfaction.

CONCLUSIONS

The prevalence of ADHD symptoms among Chinese medical students could be relatively high. Inattention is significantly related to life satisfaction among the students. Early identification of medical students with ADHD symptoms should be warranted. Resilience intervention programs might be undertaken to enhance life satisfaction in medical students, especially for those with inattention symptoms.

Clinical practice: Adult attention deficit-hyperactivity disorder

Short-term trials involving adults with ADHD have shown significant improvements in symptoms with stimulants and atomoxetine; however, data on long-term benefits and risks of these medications, particularly among older persons, have been insufficient.

Adrenergic α2A receptor gene is not associated with methylphenidate response in adults with ADHD

Adrenergic α2A receptor gene (ADRA2A) is one of the most promising candidate genes for ADHD pharmacogenetics. Thus far, three studies have investigated the association between the ADRA2A -1291 C>G polymorphism and the therapeutic response to methylphenidate (MPH) in children with ADHD, all of them with positive results. The aim of this study is to investigate, for the first time, the association between three ADRA2A polymorphisms (-1291 C>G, -262 G>A, and 1780 C>T) and the response to MPH in adults with ADHD. The sample comprises 165 Brazilians of European descent evaluated in the adult ADHD outpatient clinic of the Hospital de Clínicas de Porto Alegre. The diagnostic procedures followed the DSM-IV criteria. Drug response was assessed by both categorical and dimensional approaches, through the scales Swanson, Nolan, and Pelham Rating scale version IV and the Clinical Global Impression-Severity Scale, applied at the beginning and after the 30th day of treatment. We found no evidence of association between the three ADRA2A polymorphisms and the therapeutic response to MPH treatment. Our findings do not support a significant role for the ADRA2A gene in ADHD pharmacogenetics, at least among adult patients.