Motor regulation problems and pain in adults diagnosed with ADHD

Acute aerobic exercise modulates cognition and cortical excitability in adults with attention-deficit hyperactivity disorder (ADHD) and healthy controls

Evidence suggests aerobic exercise has beneficial effects on cognitive performance in adults with attention-deficit hyperactivity disorder (ADHD). The underlying mechanisms might depend on mechanisms of exercise-mediated brain physiology. The study aims to investigate the effects of acute aerobic exercise on cortical excitability and cognitive performance, and the correlation between these phenomena in adults with ADHD. Twenty-six drug-naïve ADHD adults, and twenty-six age-, and gender-matched healthy controls were assessed with respect to cortical excitability and cognitive performance before and after acute aerobic exercise (a single session for 30 min) or a control intervention. The results show significantly enhanced intracortical facilitation (ICF) and decreased short intracortical inhibition (SICI) after aerobic exercise in healthy subjects. In contrast, SICI was significantly enhanced following acute aerobic exercise in ADHD. In ADHD, furthermore inhibitory control and motor learning were significantly improved after the acute aerobic exercise intervention. Alterations of SICI induced by aerobic exercise, and inhibitory control and motor learning improvement were significantly positively correlated in the ADHD group. Aerobic exercise had partially antagonistic effects in healthy controls, and ADHD patients. Furthermore, aerobic exercise-induced cognition-enhancing effects in ADHD depend on specific alterations of brain physiology, which differ from healthy humans.

The Utility of Neuromuscular Assessment to Identify ADHD Among Patients with a Complex Symptom Picture

OBJECTIVE

Diagnostic assessment of ADHD is challenging due to comorbid psychopathologies and symptoms overlapping with other psychiatric disorders. In this study, we investigate if a distinct pattern of neuromuscular dysregulation previously reported in ADHD, can help identifying ADHD in psychiatric patients with diverse and complex symptoms.

METHOD

We explored the impact of neuromuscular dysregulation, as measured by The Motor Function Neurologic Assessment (MFNU), on the likelihood of being diagnosed with ADHD, affective disorder, anxiety disorder, or personality disorder among adults (n = 115) referred to a psychiatric outpatient clinic.

RESULTS

Logistic regression revealed that neuromuscular dysregulation was significantly associated with ADHD diagnosis only (OR 1.15, p < .01), and not with affective-, anxiety-, or personality disorders. Sensitivity and specificity for ADHD at different MFNU scores is provided.

CONCLUSIONS

A test of neuromuscular dysregulation may promote diagnostic accuracy in differentiating ADHD from other psychiatric disorders in patients with an overlapping symptom picture. This may have important implications for clinical practice. More studies are needed.

Childhood Reading Ability and Pain in Childhood Through to Midlife

Dyslexia and pain have recently been shown to correlate on a genetic level, but there has been little exploration of this association on the phenotypic level despite reports of increased pain in Attention Deficit Hyperactivity Disorder, which commonly co-occurs with dyslexia. In this study we test for an association between reading ability, which is the primary feature of dyslexia, and pain both in childhood and adulthood. Logistic regression modeling was used to test associations between reading ability in childhood and pain from childhood to midlife in a large UK birth cohort; the 1958 National Child Development Study. Associations were found between poor childhood reading ability and increased headache and abdominal pain in childhood, and between poor childhood reading ability and headache, eye pain, back pain, and rheumatism in adulthood. Mediation analyses indicated that socioeconomic status (defined by employment) fully mediated the association between poor reading ability in childhood and back pain at age 42. By contrast, the association between reading ability and eye pain acted independently of socioeconomic status. Different mechanisms were thus indicated for the association of reading with different pain types, including manual labor and a potential shared biological pathway. PERSPECTIVE: This study found a relationship between poor reading ability in childhood and pain in childhood and adulthood. Those with reading difficulties should be monitored for pain symptoms. Future research may uncover shared biological mechanisms, increasing our understanding of pain and potential treatments.

Selenoprotein T, a potential treatment of attention-deficit/hyperactivity disorder and comorbid pain in neonatal 6-OHDA lesioned mice

pathological pain and Attention-deficit/hyperactivity disorder (ADHD) are two complex multifactorial syndromes. The comorbidity of ADHD and altered pain perception is well documented in children, adolescents, and adults. According to pathophysiological investigations, the dopaminergic system's dysfunction provides a common basis for ADHD and comorbid pain. Growing evidence suggests that oxidative stress may be crucial in both pathologies. Recent studies revealed that a small peptide encompassing the redox-active site of selenoprotein T (PSELT), protects dopaminergic neurons and fibers as well as lesioned nerves in animal models. The current study aims to examine the effects of PSELT treatment on ADHD-like symptoms and pain sensitivity, as well as the role of catecholaminergic systems in these effects. Our results demonstrated that intranasal administration of PSELT reduced the hyperactivity in the open field, decreased the impulsivity displayed by 6-OHDA-lesioned male mice in the 5-choice serial reaction time task test and improved attentional performance. In addition, PSELT treatment significantly increased the nociception threshold in both normal and inflammatory conditions. Furthermore, anti-hyperalgesic activity was antagonized with sulpiride pre-treatment, but not by phentolamine, or propranolol pre-treatments. The present study suggests that PSELT reduces the severity of ADHD symptoms in mice and possesses potent antinociceptive effects which could be related to the involvement of D2/D3 dopaminergic receptors.

Motor proficiency of persons with attention deficit hyperactivity disorder or autism spectrum disorder diagnosed in adulthood

PURPOSE

To compare (1) motor proficiency of persons diagnosed in adulthood with attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) with normative values of motor proficiency, and (2) motor proficiency between persons with ADHD and those with ASD diagnosed in adulthood.

METHODS

A total of 153 adults (median age 32 years, 36% women) participated in this cross-sectional study. Fifty-three persons with predominately inattentive presentation (ADHD-I), 67 persons with combined presentation (ADHD-C), and 33 persons with ASD performed the Bruininks-Oseretsky Test of Motor Proficiency (BOT-2). One-sample binominal tests were used to compare motor proficiency against standardized norms of BOT-2 for young adults. One-way ANOVAs and Kruskal-Wallis tests were used to compare test outcomes between the groups.

RESULTS

The total sample showed significantly impaired motor proficiency in comparison to norms in all test domains (p < 0.001-0.006), except for fine motor skills. The ASD group showed significantly poorer body coordination compared with the ADHD-I and ADHD-C groups, with a moderate effect size (p = 0.003-0.02, η2 = 0.061).

CONCLUSIONS

Motor proficiency is impaired in most persons with ADHD or ASD diagnosed in adulthood, suggesting that motor assessment should be included in clinical examinations of adults with suspected neurodevelopment disorders.

P2X4 signalling contributes to hyperactivity but not pain sensitization comorbidity in a mouse model of attention deficit/hyperactivity disorder

Introduction: Attention deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder characterized by hyperactivity, inattention, and impulsivity that often persist until adulthood. Frequent comorbid disorders accompany ADHD and two thirds of children diagnosed with ADHD also suffer from behavioural disorders and from alteration of sensory processing. We recently characterized the comorbidity between ADHD-like symptoms and pain sensitisation in a pharmacological mouse model of ADHD, and we demonstrated the implication of the anterior cingulate cortex and posterior insula. However, few studies have explored the causal mechanisms underlying the interactions between ADHD and pain. The implication of inflammatory mechanisms has been suggested but the signalling pathways involved have not been explored. Methods: We investigated the roles of purinergic signalling, at the crossroad of pain and neuroinflammatory pathways, by using a transgenic mouse line that carries a total deletion of the P2X4 receptor. Results: We demonstrated that P2X4 deletion prevents hyperactivity in the mouse model of ADHD. In contrast, the absence of P2X4 lowered thermal pain thresholds in sham conditions and did not affect pain sensitization in ADHD-like conditions. We further analysed microglia reactivity and the expression of inflammatory markers in wild type and P2X4KO mice. Our results revealed that P2X4 deletion limits microglia reactivity but at the same time exerts proinflammatory effects in the anterior cingulate cortex and posterior insula. Conclusion: This dual role of P2X4 could be responsible for the differential effects noted on ADHD-like symptoms and pain sensitization and calls for further studies to investigate the therapeutic benefit of targeting the P2X4 receptor in ADHD patients.

ADHD-pain: Characteristics of chronic pain and association with muscular dysregulation in adults with ADHD

OBJECTIVES

A high incidence of attention-deficit hyperactivity disorder (ADHD) has been reported in chronic pain (ChP) patients. Furthermore, an association between ChP and muscular dysregulation has been reported in adults with ADHD. The present study investigated whether ADHD was more prevalent among psychiatric outpatients with ChP than those without ChP, and if there was an association between ChP, muscular dysregulation and characteristics of pain in patients with ADHD.

METHODS

One-hundred and twenty-one individuals remitted to an outpatient psychiatry unit took part in this naturalistic epidemiological cross-sectional study. They were assessed with a pain self-report form (localization, intensity, and onset) and a test of muscle dysregulation (the Motor Function Neurological Assessment). Prevalence of ADHD among patients with ChP, as well as the qualitative characteristics of ChP within the ADHDgroup are reported. Both ChP and pain intensity correlated with muscular dysregulation through Spearman's rho analysis. Additionally, the relationship between various diagnostic categories (ADHD, affective disorders, anxiety, or personality disorders) and incidence of axial pain was evaluated in logistic regression.

RESULTS

ADHD was significantly more prevalent in patients with ChP, than in patients without ChP. In the ADHD group, ChP and pain intensity was associated with muscular dysregulation, particularly with high muscle tone. ChP was more axial and widespread, than for the patients without ADHD, and started at an early age. ADHD diagnosis predicted axial pain, whereas affective-, anxiety-, or personality disorders did not.

CONCLUSIONS

The study suggests that ChP in ADHD is associated with muscular dysregulation and is qualitatively different from ChP in psychiatric patients without ADHD. These findings may lead to further understanding of potential mechanisms involved in ADHD and ChP, and in turn to new treatment strategies for both disorders.

The effect of methylphenidate on pain perception thresholds in children with attention deficit hyperactivity disorder

BACKGROUND

Pain perception is important in children with attention deficit hyperactivity disorder (ADHD) since they are more likely to experience painful events due to increased accident rates. The aim of this study is to contribute to the literature concerning the relationship between ADHD diagnosis, methylphenidate (MPH) therapy, and pain thresholds, since findings regarding the change in pain perception in children with ADHD are scarce and inconsistent.

METHODS

Children aged 8-13 years constituted both the ADHD group (n = 82) and the healthy controls (n = 41). The ADHD group was divided into two subgroups, ADHD without MPH (not treated pharmacologically) and ADHD with MPH (treated pharmacologically for at least three-months). The Conners' Parent Rating Scale-Revised: Short Form was employed to assess ADHD, a visual analog scale was applied to evaluate chronic pain severity, and a manual pressure algometer was used to assess pain thresholds.

RESULT

Children with ADHD had lower pain thresholds than the healthy controls (P < 0.05). However, lower regional pain thresholds were observed in the ADHD group without MPH compared to both the healthy control and ADHD with MPH groups. Although pain thresholds in the ADHD with MPH group were regionally lower than in the healthy controls, low pain thresholds were found in fewer regions compared to the ADHD without MPH group.

CONCLUSIONS

Children with ADHD are more sensitive to pain sensation, and MPH may help normalize these individuals' pain experiences by raising pain thresholds. Families and clinicians must be aware of situations that may cause pain in children with ADHD. In addition, these children's low threshold for pain may lead them to experience it more intensely.

Effect of psychostimulant medications on static balance performance in adults with attention deficit hyperactivity disorder: Within-subjects repeated-measure study

OBJECTIVE

This study examined the effect of psychostimulant medications nPS) on balance and functional motor performance in adults with attention-deficit/hyperactivity disorder (ADHD).

METHODS

Participants completed two sessions (off-medication and on-medication) in a within-subjects repeated-measure study design. There was a minimum of seven days between the two sessions. During both sessions, participants stood for 30 s per condition on a force platform. The conditions were: feet-apart with 1) eyes-open and 2) eyes-closed; feet-together with 3) eyes-open and 4) eyes-closed. Participants performed three trials of timed up and go (TUG) and lateral step-up test (LSUT) during both sessions. Outcome measures were sway area (SA [cm²]), average sway velocity (SV [cm/s]), TUG average time (s), and average number of LSUT repetitions. Data were analyzed using multivariate repeated measures analysis of variance and paired t-tests for examining PS effects on balance (SA and SV) and functional motor performance (TUG and LSUT), respectively.

RESULTS

The sample included 45 adults (35 females; mean age = 28.4 ± 6.3 years). The repeated-measures MANOVA indicated that PS was associated with better SA [F(1,44) = 9.6; p = 0.003;η_p² = 0.18] but not with SV [F(1,44) = 1.0; p = 0.319;η_p² = 0.02]. PS was associated with significantly better SA with decreasing base-of-support [F(1,44) = 9.9; p = 0.003;η_p² = 0.18]. Additionally, PS use was associated with better TUG [t(1,44) = 2.65; p = 0.014;Cohen's d = 0.39] but not LSUT performances [t(1,44) = -0.68; p = 0.499;Cohen's d = -0.10].

CONCLUSIONS

PS was associated with better SA and TUG in adults with ADHD. Further studies are needed to investigate the effects of PS on balance performance using rigorous designs in this population.

IMPACT

Healthcare providers should screen for PS status and balance when treating adults with ADHD to enhance safe motor performance.

Case report: Methylphenidate improved chronic pain in an adult patient with attention deficit hyperactivity disorder

Introduction

Chronic pain remains a health problem that is difficult to treat adequately. Its unknown cause and complex comorbidity with other illnesses, including mental disorders, amplify the severity of symptoms, which consequently decreases the quality of life of patients long term. In our clinical practice, we coincidentally found evidence that methylphenidate (MPH) effectively managed chronic pain in an adult patient with attention deficit hyperactivity disorder (ADHD). The effectiveness of MPH in the treatment of ADHD is well-established; however, its utility in treating pain remains unclear.

Case presentation

We present a rare case of a 43-year-old male patient with 15 years of chronic idiopathic pain symptoms that did not adequately respond to standard pain management, such as acetaminophen, non-opioid analgesics, and muscle relaxers. Pain also persisted after treatments with antidepressants and an epidural block. Furthermore, symptoms worsened following several sessions of modified electroconvulsive therapy. After a thorough assessment at our child and adolescent psychiatric outpatient clinic, we confirmed a diagnosis of adult ADHD with a predominantly inattentive type. Considering this newly established diagnosis, we prescribed osmotic-release oral system (OROS) methylphenidate. Within 1 month of treatment at a dose of 18 mg/day of OROS-MPH, the patient’s chronic pain unexpectedly improved dramatically, and the patient no longer experienced pain symptoms. The dosage of OROS-MPH was titrated monthly, reaching 72 mg/day as a maintenance dose, and ADHD symptoms improved after 4 months of treatment. The patient was followed up regularly for 7 years during his OROS-MPH treatment. No adverse effects were reported, including stimulant addiction. He was stable overall and functioned well in his daily activities. His pain never recurred.

Conclusion

This case report suggests that MPH may be potentially effective in treating chronic pain. Further studies are needed to confirm whether MPH improved chronic pain simultaneously with or separately from the improvement in ADHD. Moreover, elucidating the anatomical sites and molecular pharmacological mechanisms related to the action of MPH in pain modulation and perception is essential. Such sites include the descending dopaminergic pain pathway and higher cortical areas. Furthering our understanding may reinforce the justification for treating chronic pain using MPH.

Effect of atomoxetine on ADHD-pain hypersensitization comorbidity in 6-OHDA lesioned mice

BACKGROUND

Methylphenidate and atomoxetine are used for the treatment of attention-deficit/hyperactivity disorder (ADHD). Our previous studies established the validity of the 6-hydroxydopamine (6-OHDA) mouse model of ADHD and demonstrated hypersensitivity to pain, in line with clinical reports in ADHD patients. Acute methylphenidate treatment reduces hyperactivity and increases attention, but does not affect pain behaviors in this mouse model. Whereas atomoxetine has been shown to be effective against some symptoms of ADHD, nothing is known about its possible action on comorbid pain hypersensitivity. The objectives of the present research are (1) to investigate the effects of acute and chronic treatment with atomoxetine on ADHD-like symptoms and nociceptive thresholds, and (2) to explore the catecholaminergic systems underlying these effects.

METHODS

Sham and 6-OHDA cohorts of male mice were tested for hyperactivity (open field), attention and impulsivity (5-choice serial reaction time task test), and thermal (hot plate test) and mechanical (von Frey test) thresholds after acute or repeated treatment with vehicle or atomoxetine (1, 3 or 10 mg/kg).

RESULTS

Acute administration of atomoxetine (10 mg/kg) reduced the hyperactivity and impulsivity displayed by 6-OHDA mice, without affecting attention or nociception. However, atomoxetine administered at 3 mg/kg/day for 7 days alleviated the ADHD-like core symptoms and attenuated the hyperalgesic responses. Furthermore, hyperlocomotion and anti-hyperalgesic activity were antagonized with phentolamine, propranolol, and sulpiride pre-treatments.

CONCLUSION

These findings demonstrated that when administered chronically, atomoxetine has a significant effect on ADHD-associated pain hypersensitization, likely mediated by both α- and β-adrenergic and D2/D3 dopaminergic receptors, and suggest new indications for atomoxetine that will need to be confirmed by well-designed clinical trials.

Targeting Neuroinflammation with Abscisic Acid Reduces Pain Sensitivity in Females and Hyperactivity in Males of an ADHD Mice Model

Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental syndrome characterized by dopaminergic dysfunction. In this study, we aimed to demonstrate that there is a link between dopaminergic deficit and neuroinflammation that underlies ADHD symptoms. We used a validated ADHD mice model involving perinatal 6-OHDA lesions. The animals received abscisic acid (ABA), an anti-inflammatory phytohormone, at a concentration of 20 mg/L (drinking water) for one month. We tested a battery of behavior tests, learning and memory, anxiety, social interactions, and pain thresholds in female and male mice (control and lesioned, with or without ABA treatment). Postmortem, we analyzed microglia morphology and Ape1 expression in specific brain areas related to the descending pain inhibitory pathway. In females, the dopaminergic deficit increased pain sensitivity but not hyperactivity. In contrast, males displayed hyperactivity but showed no increased pain sensitivity. In females, pain sensitivity was associated with inflammatory microglia and lower Ape1 levels in the anterior cingulate cortex (ACC) and posterior insula cortex (IC). In addition, ABA treatment alleviated pain sensitivity concomitant with reduced inflammation and normalized APE1. In males, ABA reduced hyperactivity but had no significant effect on inflammation in these areas. This is the first study proving a sex-dependent association between dopamine dysfunction and inflammation in specific brain areas, hence leading to different behavioral outcomes in a mouse model of ADHD. These findings provide new clues for potential treatments for ADHD.

Associations between Chronic Pain and Attention-Deficit Hyperactivity Disorder (ADHD) in Youth: A Scoping Review

Background: Chronic pain and ADHD are common conditions among youth that negatively impact functioning. This review fills a critical gap by summarizing current research on chronic pain and ADHD comorbidity, and it proposes a conceptual model of shared associations and underlying mechanisms. Objective: The aims of the current study were to: (1) review the extant literature and present estimates of the prevalence of comorbid non-headache chronic pain and ADHD in youth and (2) describe potential shared mechanisms for ADHD and chronic non-headache pain in youth. We also outline future directions to inform future research and interventions directed to youth with comorbid pain and ADHD. Design: A scoping review of the literature was performed in MEDLINE, PsycInfo, and Cochrane Database of Systematic Reviews using a wide range of search terms related to pain, Attention Deficit-Hyperactivity Disorder, childhood, adolescence, and young adulthood. Results: Eleven published studies were included in the review. These studies examined the prevalence of chronic pain among youth with ADHD, the prevalence of ADHD in chronic pain samples, and the association between chronic pain and ADHD among youth. Findings revealed results from studies indicating a higher prevalence of ADHD among youth with chronic pain and a higher prevalence of chronic pain in samples of youth with ADHD. Conclusions: Findings from this scoping review suggest an association between chronic pain and ADHD among youth. Little research was found to examine the etiology of this association. Future studies should examine underlying mechanisms of comorbid chronic pain and ADHD.

Effects of Striatal Amyloidosis on the Dopaminergic System and Behavior: A Comparative Study in Male and Female 5XFAD Mice

BACKGROUND

Nearly two-thirds of patients diagnosed with Alzheimer's disease (AD) are female. In addition, female patients with AD have more significant cognitive impairment than males at the same disease stage. This disparity suggests there are sex differences in AD progression. While females appear to be more affected by AD, most published behavioral studies utilize male mice. In humans, there is an association between antecedent attention-deficit/hyperactivity disorder and increased risk of dementia. Functional connectivity studies indicate that dysfunctional cortico-striatal networks contribute to hyperactivity in attention deficit hyperactivity disorder. Higher plaque density in the striatum accurately predicts the presence of clinical AD pathology. In addition, there is a link between AD-related memory dysfunction and dysfunctional dopamine signaling.

OBJECTIVE

With the need to consider sex as a biological variable, we investigated the influence of sex on striatal plaque burden, dopaminergic signaling, and behavior in prodromal 5XFAD mice.

METHODS

Six-month-old male and female 5XFAD and C57BL/6J mice were evaluated for striatal amyloid plaque burden, locomotive behavior, and changes in dopaminergic machinery in the striatum.

RESULTS

5XFAD female mice had a higher striatal amyloid plaque burden than male 5XFAD mice. 5XFAD females, but not males, were hyperactive. Hyperactivity in female 5XFAD mice was associated with increased striatal plaque burden and changes in dopamine signaling in the dorsal striatum.

CONCLUSION

Our results indicate that the progression of amyloidosis involves the striatum in females to a greater extent than in males. These studies have significant implications for using male-only cohorts in the study of AD progression.

Prescription stimulant use during long-term opioid therapy and risk for opioid use disorder

Background

Concurrent therapeutic prescribing of prescription stimulants with opioid analgesics is increasing in the United States. Stimulant medication use is associated with increased risk for long-term opioid therapy (LTOT), and LTOT is associated with increased risk for opioid use disorder (OUD).

Aims

To determine if stimulant prescriptions among those with LTOT (≥90 days) are associated with greater risk for opioid use disorder (OUD).

Methods

This retrospective cohort study from 2010 to 2018 used a United States, nationally distributed Optum© analytics Integrated Claims-Clinical dataset. Patients ≥18 years of age, and free of prevalent OUD in the two years prior to index were eligible. All patients had a new ≥90-day opioid prescription. The index date was day 91. We compared risk for new OUD diagnoses in patients with and without a prescription stimulant overlapping LTOT. Entropy balancing and weighting controlled for confounding factors.

Results

Patients (n = 5,712), were 57.7 (SD±14.9) years of age on average, majority female (59.8%) and 73.3% White race. Among patients with LTOT, 2.8% had overlapping stimulant prescriptions. Before controlling for confounding, dual stimulant-opioid prescriptions, compared to opioid only, were associated with OUD risk (HR = 1.75; 95%CI:1.17-2.61). After controlling for confounding, this association was no longer present (HR = 0.89; 95%CI:0.47-1.71). Results did not differ in sensitivity analyses limiting the cohort to those <56 years of age.

Conclusions

Dual stimulant use among patients with LTOT does not increase risk for OUD. Stimulants prescribed for ADHD and other conditions may not worsen opioid outcomes for some patients with LTOT.

Pain hypersensitivity in a pharmacological mouse model of attention-deficit/hyperactivity disorder

Clinical evidence suggests that pain hypersensitivity develops in patients with attention-deficit/hyperactivity disorder (ADHD). However, the mechanisms and neural circuits involved in these interactions remain unknown because of the paucity of studies in animal models. We previously validated a mouse model of ADHD obtained by neonatal 6-hydroxydopamine (6-OHDA) injection. Here, we have demonstrated that 6-OHDA mice exhibit a marked sensitization to thermal and mechanical stimuli, suggesting that phenotypes associated with ADHD include increased nociception. Moreover, sensitization to pathological inflammatory stimulus is amplified in 6-OHDA mice as compared to shams. In this ADHD model, spinal dorsal horn neuron hyperexcitability was observed. Furthermore, ADHD-related hyperactivity and anxiety, but not inattention and impulsivity, are worsened in persistent inflammatory conditions. By combining in vivo electrophysiology, optogenetics, and behavioral analyses, we demonstrated that anterior cingulate cortex (ACC) hyperactivity alters the ACC-posterior insula circuit and triggers changes in spinal networks that underlie nociceptive sensitization. Altogether, our results point to shared mechanisms underlying the comorbidity between ADHD and nociceptive sensitization. This interaction reinforces nociceptive sensitization and hyperactivity, suggesting that overlapping ACC circuits may be targeted to develop better treatments.

The Dark Side of ADHD: Factors Associated With Suicide Attempts Among Those With ADHD in a National Representative Canadian Sample

AIM

This study investigated the prevalence and odds of suicide attempts among adults with attention deficit hyperactivity disorder (ADHD) compared to those without and identified factors associated with suicide attempts among adults with ADHD.

METHODS

Secondary analysis of the nationally representative Canadian Community Health Survey-Mental Health (CCHS-MH) (n = 21,744 adults, of whom 529 had ADHD). Respondents were asked whether they received an ADHD diagnosis from a health care professional. Lifetime suicide attempt was based on self-report.

RESULTS

Adults with ADHD were much more likely to have attempted suicide than those without (14.0% vs. 2.7%). One in four women with ADHD have attempted suicide. Sixty percent of the association between ADHD and attempted suicide was attenuated when lifetime history of depression and anxiety disorders were taken into account. Female gender, lower education attainment, substance abuse, lifetime history of depression, and childhood exposure to chronic parental domestic violence were found to be independent correlates of lifetime suicide attempts among those with ADHD.

CONCLUSION

These findings can inform targeted screening and outreach to the most vulnerable adults with ADHD.

New Insights on Gene by Environmental Effects of Drugs of Abuse in Animal Models Using GeneNetwork

Gene-by-environment interactions are important for all facets of biology, especially behaviour. Families of isogenic strains of mice, such as the BXD strains, are excellently placed to study these interactions, as the same genome can be tested in multiple environments. BXD strains are recombinant inbred mouse strains derived from crossing two inbred strains—C57BL/6J and DBA/2J mice. Many reproducible genometypes can be leveraged, and old data can be reanalysed with new tools to produce novel insights. We obtained drug and behavioural phenotypes from Philip et al. Genes, Brain and Behaviour 2010, and reanalysed their data with new genotypes from sequencing, as well as new models (Genome-wide Efficient Mixed Model Association (GEMMA) and R/qtl2). We discovered QTLs on chromosomes 3, 5, 9, 11, and 14, not found in the original study. We reduced the candidate genes based on their ability to alter gene expression or protein function. Candidate genes included Slitrk6 and Cdk14. Slitrk6, in a Chromosome14 QTL for locomotion, was found to be part of a co-expression network involved in voluntary movement and associated with neuropsychiatric phenotypes. Cdk14, one of only three genes in a Chromosome5 QTL, is associated with handling induced convulsions after ethanol treatment, that is regulated by the anticonvulsant drug valproic acid. By using families of isogenic strains, we can reanalyse data to discover novel candidate genes involved in response to drugs of abuse.

Pain catastrophizing and mental health phenotypes in adults with refractory chronic pain: A latent class analysis

Chronic pain, pain catastrophizing, and mental health disorders such as anxiety or depression frequently occur together and are challenging to treat. To help understand the relationship between these conditions, we sought to identify distinct phenotypes associated with worse pain and function. In a cohort of people with chronic pain on opioids seeking medical cannabis in New York, we conducted latent class analysis to identify clusters of participants based on pain catastrophizing and mental health symptoms of depression, anxiety, post-traumatic stress disorder (PTSD) and attention deficit/hyperactivity disorder (ADHD). We then compared clusters with respect to sociodemographic and clinical characteristics using descriptive statistics. Among 185 participants, we identified four discrete groups: low pain catastrophizing and low mental health symptoms (49% of participants), low pain catastrophizing and ADHD-predominant mental health symptoms (11%), high pain catastrophizing and anxiety-predominant mental health symptoms (11%), and high pain catastrophizing and high mental health symptoms (30%). The group with high pain catastrophizing and high mental health symptoms had the worst pain intensity and interference, disability, insomnia, and quality of life, compared to the two groups with lower pain catastrophizing, though not all differences were statistically significant. Our findings highlight the importance of identifying and addressing pain catastrophizing in patients with comorbid chronic pain and mental health symptoms.

Large-scale genetic investigation reveals genetic liability to multiple complex traits influencing a higher risk of ADHD

Attention Deficit-Hyperactivity Disorder (ADHD) is a complex psychiatric and neurodevelopmental disorder that develops during childhood and spans into adulthood. ADHD’s aetiology is complex, and evidence about its cause and risk factors is limited. We leveraged genetic data from genome-wide association studies (GWAS) and performed latent causal variable analyses using a hypothesis-free approach to infer causal associations between 1387 complex traits and ADHD. We identified 37 inferred potential causal associations with ADHD risk. Our results reveal that genetic variants associated with iron deficiency anemia (ICD10), obesity, type 2 diabetes, synovitis and tenosynovitis (ICD10), polyarthritis (ICD10), neck or shoulder pain, and substance use in adults display partial genetic causality on ADHD risk in children. Genetic variants associated with ADHD have a partial genetic causality increasing the risk for chronic obstructive pulmonary disease and carpal tunnel syndrome. Protective factors for ADHD risk included genetic variants associated with the likelihood of participating in socially supportive and interactive activities. Our results show that genetic liability to multiple complex traits influences a higher risk for ADHD, highlighting the potential role of cardiometabolic phenotypes and physical pain in ADHD’s aetiology. These findings have the potential to inform future clinical studies and development of interventions.

Neuroinflammation as a possible link between attention-deficit/hyperactivity disorder (ADHD) and pain

Attention-deficit/hyperactivity disorder (ADHD) and pathological pain are two complex syndromes of multifactorial origin. Despite their prevalence and broad impacts, these conditions are seldom recognized and managed simultaneously. The co-existence of neuropsychiatric conditions (such as ADHD) and altered pain perception and chronic pain has been noted in children, and the comorbidity of ADHD and chronic pain is well documented in adults. Pathophysiological studies have suggested dysfunction of the dopaminergic system as a common neurochemical basis for comorbid ADHD and pain. Considerable evidence supports the role of neuroinflammation in the pathophysiology of both. We suggest that central neuroinflammation underlies altered pain perception and pain sensitization in persons with ADHD. Based on our hypothesis, targeting neuroinflammation may serve as a potential new therapeutic intervention to treat ADHD and comorbid pain in children and adolescents and a preventive strategy for the development of chronic pain in adults with ADHD.

Common and Unique Genetic Background between Attention-Deficit/Hyperactivity Disorder and Excessive Body Weight

Comorbidity studies show that children with ADHD have a higher risk of being overweight and obese than healthy children. This study aimed to assess the genetic alternations that differ between and are shared by ADHD and excessive body weight (EBW). The sample consisted of 743 Polish children aged between 6 and 17 years. We analyzed a unique set of genes and polymorphisms selected for ADHD and/or obesity based on gene prioritization tools. Polymorphisms in the KCNIP1, SLC1A3, MTHFR, ADRA2A, and SLC6A2 genes proved to be associated with the risk of ADHD in the studied population. The COMT gene polymorphism was one that specifically increased the risk of EBW in the ADHD group. Using the whole-exome sequencing technique, we have shown that the ADHD group contains rare and protein-truncating variants in the FBXL17, DBH, MTHFR, PCDH7, RSPH3, SPTBN1, and TNRC6C genes. In turn, variants in the ADRA2A, DYNC1H1, MAP1A, SEMA6D, and ZNF536 genes were specific for ADHD with EBW. In this way, we confirmed, at the molecular level, the existence of genes specifically predisposing to EBW in ADHD patients, which are associated with the biological pathways involved in the regulation of the reward system, intestinal microbiome, and muscle metabolism.

Primary dysmenorrhea in adolescents: Association with attention deficit hyperactivity disorder and psychological symptoms

OBJECTIVE

No prior study has investigated the relation of primary dysmenorrhea (PD) with attention deficit hyperactivity disorder (ADHD) symptoms in adolescent age groups. This study aimed to investigate the relationship of PD with ADHD and psychological symptoms among adolescents. Another objective was to examine the PD related non-psychogenic factors and sleep quality.

MATERIALS AND METHODS

Two hundred nine adolescent girls who applied to policlinics for various reasons were enrolled. All participants completed self-report questionnaires. Questionnaire for sociodemographic data, menstrual pattern and dysmenorrhea in adolescents, Visual analog scale, Pittsburgh Sleep Quality Index, DSM-5 Level 2 Sleep Disorders Scale, Brief Symptom Inventory, and the Turgay Diagnostic and Statistical Manual of Mental Disorders, 4th edition-Based Child and Adolescent Disruptive Behavior Disorders Screening and Rating Scale were used to measure outcomes.

RESULTS

A hundred and four (49.8%) adolescents reported having pain that affects daily activities during menstruation. These adolescents had worse sleep quality, more inattention and hyperactivity-impulsivity problems, and other psychological symptoms of anxiety, depression, somatization, negative self-perception, and hostility in comparison to others (P < 0.05). The menstrual pain severity, measured by VAS, was positively correlated with ADHD symptoms and all other psychological parameters (P < 0.05).

CONCLUSION

PD affecting daily-activities may be related to ADHD symptoms and psychiatric distress. Future studies are needed to support the association between ADHD and PD. Assessing the psychiatric problems of adolescents with dysmenorrhea is important.

Mental Disorders, Musculoskeletal Disorders and Income-Driven Patterns: Evidence from the Global Burden of Disease Study 2017

Background: The aim of the present study was to use the extensive Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) database from 1990–2017 to evaluate the levels and temporal correlation trends between disability adjusted life years (DALYs) attributed to musculoskeletal (MSK) disorders, all mental disorders collectively and by mental disorder sub-category. Methods: We utilized results of the GBD 2017 to describe the correlation patterns between DALYs due to MSK disorders, mental disorders and other diseases among 195 countries. Mixed model analysis was also applied. Results: A consistent relation was reported between age-adjusted DALYs attributed to MSK and mental disorders (in total) among the 195 countries, in both sexes, for 1990 to 2017 (1990 Rho = 0.487; 2017 Rho = 0.439 p < 0.05). Distinct regional and gender correlation patterns between age-adjusted DALYs due to MSK and mental disorders were reported. No correlation was reported between DALYs due to MSK and all mental disorders collectively, among Low- or Middle-income countries. However, in High-income countries (HICs), the correlation was strong and consistent between 1990 and 2017 (1990 Rho = 0.735; 2017 Rho = 0.727, p < 0.05). Conclusions: The reported correlation patterns call for targeted preventive strategies and intervention policies for mental and MSK disorders internationally. Special attention is needed among HICs.

Conduct disorder and attention-deficit/hyperactivity disorder as risk factors for prescription opioid use

BACKGROUND

Existing studies of attention deficit/hyperactivity disorder (ADHD), conduct disorder (CD), and substance use or substance use disorders have produced mixed results, with some identifying a direct link between ADHD and general or disordered substance use and others suggesting that comorbid CD may explain this relationship. Insufficient research has addressed the issue, which is particularly relevant in the context of the opioid crisis. This study examined the association of probable ADHD and childhood CD with self-reported opioid use in a general-population sample.

METHOD

The 2011-2013 cycles of the CAMH Monitor, a cross-sectional survey of adults (18+ years) from Ontario, Canada provided data from 6074 respondents. Binary logistic regressions were conducted of self-reported medical, non-medical, and any prescription opioid use in the previous 12 months, assessing demographic characteristics, perceived physical and mental health, and probable ADHD, childhood (before age 15 years) symptoms of CD, or their combination.

RESULTS

Adjusting for potential covariates, probable ADHD alone was not associated with prescription opioid use. Childhood symptoms of CD significantly predicted non-medical use (OR = 2.10, 95% CI = 1.10, 4.03). ADHD and CD symptoms combined significantly predicted medical (OR = 3.27, 95% CI = 1.20, 8.91), non-medical (OR = 4.73, 95% CI = 1.05, 21.30), and any (OR = 3.02, 95% CI = 1.13, 8.11) prescription opioid use, although a low base rate of non-medical use may have negatively affected model fit.

CONCLUSIONS

Previous findings relating ADHD to opioid use could be explained, in part, by the high rate of comorbidity between ADHD and CD. These data support prevention and treatment programs targeting individuals with comorbid ADHD and CD symptoms.

Mouse movement measures enhance the stop-signal task in adult ADHD assessment

The accurate detection of attention-deficit/hyperactivity disorder (ADHD) symptoms, such as inattentiveness and behavioral disinhibition, is crucial for delivering timely assistance and treatment. ADHD is commonly diagnosed and studied with specialized questionnaires and behavioral tests such as the stop-signal task. However, in cases of late-onset or mild forms of ADHD, behavioral measures often fail to gauge the deficiencies well-highlighted by questionnaires. To improve the sensitivity of behavioral tests, we propose a novel version of the stop-signal task (SST), which integrates mouse cursor tracking. In two studies, we investigated whether introducing mouse movement measures to the stop-signal task improves associations with questionnaire-based measures, as compared to the traditional (keypress-based) version of SST. We also scrutinized the influence of different parameters of stop-signal tasks, such as the method of stop-signal delay setting or definition of response inhibition failure, on these associations. Our results show that a) SSRT has weak association with impulsivity, while mouse movement measures have strong and significant association with impulsivity; b) machine learning models trained on the mouse movement data from "known" participants using nested cross-validation procedure can accurately predict impulsivity ratings of "unknown" participants; c) mouse movement features such as maximum acceleration and maximum velocity are among the most important predictors for impulsivity; d) using preset stop-signal delays prompts behavior that is more indicative of impulsivity.

Neuropsychological Performance Patterns of Adult ADHD Subtypes

Objective: Neuropsychological performance patterns associated with adult ADHD subtypes are unknown. The aim of the current systematic review was to identify and synthesize available literature regarding neuropsychological performance associated with adult ADHD subtypes. Method: Searches were completed using the databases PsycINFO and PubMed for studies published before March 2017 addressing adult ADHD subtypes and neuropsychological performance. Data characterizing the neuropsychological tests utilized in each study were obtained and sorted into eight domains. To summarize the results of all comparisons (ADHD subtype compared with control, or to each other), we counted the proportion of tests within each domain with significant group differences. Results/Conclusion: We deemed four domains informative in differentiating ADHD subtypes from controls. Of these, memory was the only domain that held promise in distinguishing ADHD-Inattentive and ADHD-Combined. Limitations of the available literature are highlighted and recommendations for future research are provided.

Pain, Bullying Involvement, and Mental Health Problems Among Children and Adolescents With ADHD in Taiwan

OBJECTIVE

The aim of this study was to examine the relationships of pain and pain-induced functional impairment with bullying involvement, as well as the relationships between pain and mental health problems among 474 children and adolescents with ADHD.

METHOD

The levels of pain, pain-induced functional impairment, involvement in bullying, depression, anxiety, ADHD symptoms, and sleep quality were assessed.

RESULTS

Both victims of verbal and relational bullying and victims of physical bullying were more likely to have pain and pain-induced functional impairment than nonvictims. The perpetrators of verbal and relational bullying were more likely to have pain than the nonperpetrators. Participants with pain and pain-induced functional impairment experienced more severe depression and anxiety and worse sleep quality than did those without pain or pain-induced functional impairment.

CONCLUSION

Clinical and educational professionals should consider the possibility of involvement in bullying and comorbid depression, anxiety, and poor sleep quality among ADHD children and adolescents with pain problems.

Gender and hand dominance on fine motor skills among Grade 1–7 learners with attention-deficit hyperactivity disorder

Children diagnosed with attention-deficit/hyperactivity disorder encounter difficulties in many activities in their daily lives that require motor coordination skills. The aim of this study was to establish whether children with attention-deficit/hyperactivity disorder have deficits in fine motor skills. Eighty male and female learners diagnosed with attention-deficit/hyperactivity disorder matched with 80 non-attention-deficit/hyperactivity disorder from the North West and Limpopo provinces (South Africa), aged 7–13  years, participated in the study. All participants completed the grooved pegboard test, the maze coordination task, and the finger tapping test. These instruments measure various functions of motor speed and eye–hand coordination. The findings reveal that children with attention-deficit/hyperactivity disorder performed significantly poorer than the control group with regard to the grooved pegboard and maze coordination tasks, but not with the finger tapping task. There were no gender differences in all the tests. Performance on the maze coordination task with the non-dominant hand was poorer for the attention-deficit/hyperactivity disorder group with regard to the time taken to complete the task. However, no hand dominance differences were found on the grooved pegboard and finger tapping tests. The study revealed a relationship between attention-deficit/hyperactivity disorder symptomatology and motor problems with regard to complex tasks of accuracy, but not on a simple task of motor speed. It is, therefore, recommended that since children with attention-deficit/hyperactivity disorder show motor deficiencies, motor skill training should be considered as part of the intervention, as these skills are needed for many daily activities and academic competencies.

Prevalence of autism traits and attention-deficit hyperactivity disorder symptoms in a clinical sample of children and adolescents with chronic pain

Purpose

Recent research has suggested that autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) may be comorbid to pediatric chronic pain, but the empirical support is yet scarce. Therefore, the current study aimed to investigate the occurrence of traits and symptoms consistent with clinically significant ASD and ADHD in a group of children and adolescents with chronic debilitating pain and examine potential differences in pain and demographic variables between children with and without clinically significant traits and symptoms of ASD and ADHD.

Patients and methods

This cross-sectional study included 146 parent–child dyads (102 girls, 111 mothers, children 8–17 years) consecutively referred to a tertiary pain clinic. Parents completed the Social Responsiveness Scale to assess autistic traits, and Conners-3 to measure symptoms of ADHD in their children. Children completed the Lübeck Pain Questionnaire to evaluate experienced pain.

Results

Among children, 20 (13.7%) received scores consistent with clinically significant ASD and 29 (19.9%) received scores consistent with clinically significant ADHD, with a combined prevalence of clinically significant ASD/ADHD traits and symptoms of 26% of the total sample. Only 4.8% of children were previously diagnosed with either disorder. Among children with clinically significant ASD traits, girls were more prevalent, parents reported lower health, and the pain was more likely triggered by being in school. Among children with clinically significant ADHD symptoms, there were no gender differences and pain was more likely triggered by the family situation and new situations. No differences regarding pain intensity, duration, or frequency were found between children with and without clinically significant ASD traits or ADHD symptoms.

Conclusion

Children with debilitating chronic pain, particularly girls, may present with an elevated risk of having a comorbid, possibly high-functioning, neurodevelopmental disorder. Results suggest that clinical assessment of pediatric chronic pain should include screening for neurodevelopmental disorders.

Standardised assessment of functioning in ADHD: consensus on the ICF Core Sets for ADHD

Attention-deficit/hyperactivity disorder (ADHD) is associated with significant impairments in social, educational, and occupational functioning, as well as specific strengths. Currently, there is no internationally accepted standard to assess the functioning of individuals with ADHD. WHO's International Classification of Functioning, Disability and Health-child and youth version (ICF) can serve as a conceptual basis for such a standard. The objective of this study is to develop a comprehensive, a common brief, and three age-appropriate brief ICF Core Sets for ADHD. Using a standardised methodology, four international preparatory studies generated 132 second-level ICF candidate categories that served as the basis for developing ADHD Core Sets. Using these categories and following an iterative consensus process, 20 ADHD experts from nine professional disciplines and representing all six WHO regions selected the most relevant categories to constitute the ADHD Core Sets. The consensus process resulted in 72 second-level ICF categories forming the comprehensive ICF Core Set-these represented 8 body functions, 35 activities and participation, and 29 environmental categories. A Common Brief Core Set that included 38 categories was also defined. Age-specific brief Core Sets included a 47 category preschool version for 0-5 years old, a 55 category school-age version for 6-16 years old, and a 52 category version for older adolescents and adults 17 years old and above. The ICF Core Sets for ADHD mark a milestone toward an internationally standardised functional assessment of ADHD across the lifespan, and across educational, administrative, clinical, and research settings.

Prevalence of and Factors Associated With Long-term Concurrent Use of Stimulants and Opioids Among Adults With Attention-Deficit/Hyperactivity Disorder

IMPORTANCE

There exist limited data on the long-term concurrent use of stimulants and opioids among adults with attention-deficit/hyperactivity disorder (ADHD), a population at risk for prescription drug abuse.

OBJECTIVE

To assess the prevalence and secular trends of and the factors associated with long-term concurrent use of stimulants and opioids among adults with ADHD.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study assessed Medicaid Analytic eXtract data from 29 states between 1999 and 2010. Medicaid fee-for-service enrollees aged 20 to 64 years with ADHD who were continuously enrolled for more than 12 months after receiving an ADHD diagnosis were included. One 12-month continuous enrollment period was randomly selected as an observation unit for each enrollee. Multivariable regression models were used to determine secular trends in the prevalence of and the potential risk factors associated with long-term concurrent stimulant-opioid use. Analyses were conducted between January 1 and December 31, 2017.

EXPOSURES

Risk factors measured during the first half of the 12-month observation unit.

MAIN OUTCOMES AND MEASURES

Prevalence of long-term use of stimulants and opioids overlapping for at least 30 consecutive days was measured during the second half of the randomly selected 12-month observation unit.

RESULTS

Of the 66 406 Medicaid-enrolled adults with ADHD who were identified as eligible, 35 670 (53.7%) were 20 to 30 years old, 37 155 (56.0%) were women, and 52 551 (79.1%) were non-Hispanic white individuals. Of these 66 406 adults with ADHD, 21 723 (32.7%) used stimulants, and 3590 (5.4%) were long-term users of stimulants and opioids. Long-term opioid use was more common among adults with ADHD who used stimulants (3590 of 21 723 [16.5%]) than among those with ADHD who did not use stimulants (5826 of 44 683 [13.0%]). Long-term concurrent stimulant-opioid use increased between 1999 and 2010 (adjusted prevalence relative ratio [PRR], 1.12; 95% CI, 1.10-1.14). Compared with patients aged 20 to 30 years, the prevalence of long-term concurrent stimulant-opioid use was higher among patients in their 30s (PRR, 1.07; 95% CI, 1.07-1.08) and was further increased among patients in their 40s (PRR, 1.14; 95% CI, 1.12-1.15) and 50s (PRR, 1.17; 95% CI, 1.16-1.19). Other strongly associated risk factors included being non-Hispanic white (black PRR, 0.93; 95% CI, 0.92-0.93; other PRR, 0.97; 95% CI, 0.97-0.98; vs white), living in the southern United States (Midwest PRR, 0.98; 95% CI, 0.97-0.98; Northeast PRR, 0.94; 95% CI, 0.93-0.94; West PRR, 0.95; 95% CI, 0.94-0.96; vs South), and receiving a diagnosis of substance abuse disorder (PRR, 1.04; 95% CI, 1.03-1.05), depression (PRR, 1.02; 95% CI, 1.01-1.03), anxiety disorder (PRR, 1.05; 95% CI, 1.04-1.07), chronic pain (PRR, 1.10; 95% CI, 1.07-1.13), chronic obstructive pulmonary disease (PRR, 1.05; 95% CI, 1.04-1.07), or cardiovascular disease (PRR, 1.02; 95% CI, 1.01-1.03).

CONCLUSIONS AND RELEVANCE

Long-term concurrent use of stimulants and opioids among adults with ADHD is common. This study suggests that clinical and research priorities should be made toward understanding the benefits and risks of long-term coadministration of stimulants and opioids in the management of ADHD and co-occurring pain conditions.

Health-related quality of life and burden of illness in adults with newly diagnosed attention-deficit/hyperactivity disorder in Sweden

BACKGROUND

This observational, cross-sectional, retrospective chart review aimed to identify factors determining health-related quality of life (HRQoL) in adults with newly diagnosed attention-deficit/hyperactivity disorder (ADHD) in Sweden.

METHODS

Adult participants with a new clinical diagnosis of ADHD were enrolled from two specialist outpatient clinics in Stockholm, Sweden, from 2013 to 2015. Data extracted from patient records included demographics, clinical characteristics and comorbid psychiatric diagnoses identified using the Mini International Neuropsychiatric Interview (MINI). Depression severity was assessed using the Montgomery-Åsberg Depression Rating Scale - Self-reported (MADRS-S). The self-rated five-dimension EuroQol questionnaire (EQ-5D) was used to measure HRQoL. Predictors of EQ-5D index score were identified using multivariate linear regression adjusting for age, sex, education level, and main income source.

RESULTS

The mean age of the 189 enrolled patients was 35.2 years (standard deviation [SD], 12.3), and 107 (57%) were female. Psychiatric comorbidities were present in 92 patients (49%), with anxiety and depression being the most common diagnoses. The mean EQ-5D index score was 0.63 (SD, 0.28). Low EQ-5D index scores were significantly associated with high MADRS-S scores, multiple comorbid psychiatric disorders, low educational achievement, female sex, and not having a main income derived from employment or self-employment.

CONCLUSIONS

These findings suggest that adults with newly diagnosed ADHD experience low HRQoL, which may often be exacerbated by psychiatric comorbidities such as anxiety and depression. Patients presenting with ADHD and psychiatric comorbidities in adulthood may require particular care and resources in the management of their ADHD.

Adult ADHD and Comorbid Somatic Disease: A Systematic Literature Review

OBJECTIVE

To systematically review, synthesize, and appraise available evidence, connecting adult ADHD with somatic disease.

METHOD

Embase, Psychinfo, and Medline databases were searched for studies published from 1994 to 2015 addressing adult ADHD and somatic comorbidity. Somatic conditions were classified according to International Classification of Diseases (ICD-10) codes. Levels of evidence were graded as inconclusive, tentative, or well documented.

RESULTS

Most of the 126 studies included in the qualitative synthesis were small and of modest quality. Obesity, sleep disorders, and asthma were well-documented comorbidities in adult ADHD. Tentative evidence was found for an association between adult ADHD and migraine and celiac disease. In a large health registry study, cardiovascular disease was not associated with adult ADHD.

CONCLUSION

There are few large systematic studies using standardized diagnostic criteria evaluating adult ADHD and somatic comorbidities. Significant associations are found between adult ADHD and several somatic diseases, and these are important to consider when assessing and treating either adult ADHD or the somatic diseases.

Effects of Physical Limitations on Daily Activities Among Adults With Mental Health Disorders: Opportunities for Nursing and Occupational Therapy Interventions

Individuals living with mental health disorders served by the public mental health system often face comorbid medical conditions that affect their quality of life and lifespan. The effect of physical limitations on the engagement in daily activities among individuals living with mental health disorders has not been extensively researched. Adults attending community wellness centers (N = 53) in a northeastern United State were included in a descriptive study exploring the impact of physical limitations on daily activities. The activities most frequently affected were: walking or moving around, sleeping, and finding a job. The physical limitations affecting these three activities were lack of energy and pain. Health care professionals, including mental health nurses and occupational therapy practitioners, are in an ideal position to collaborate by evaluating and offering treatment interventions that address physical limitations to positively affect occupational functioning and recovery. [Journal of Psychosocial Nursing and Mental Health Services, 55(10), 45-51.].

Perception in attention deficit hyperactivity disorder

A large body of research demonstrated that individuals with attention deficit hyperactivity disorder (ADHD) suffer from various neuropsychological deficits. In contrast, less is known and only divergent evidence exists on perceptual functions of individuals with ADHD. This is problematic as neuropsychological and perceptual functions are closely interrelated and are often difficult to disentangle in behavioral assessments. This study presents the conduct and results of a systematic literature review on perceptual functions in children and adults with ADHD. This review considers studies using psychophysical methods (objective measurements) and self- and informant reports (subjective measurements). Results indicate that individuals with ADHD have altered perceptual functions in various domains as compared to typically developing individuals. Increased perceptual functions in individuals with ADHD were found with regard to olfactory detection thresholds, whereas reduced perceptual functions were evident for aspects of visual and speech perception. Moreover, individuals with ADHD were found to experience discomfort to sensory stimuli at a lower level than typically developing individuals. Alterations of perceptual functions in individuals with ADHD were shown to be moderated by various factors, such as pharmacological treatment, cognitive functions, and symptom severity. We conclude by giving implications for daily life functioning and clinical practice.

ADHD symptoms and pain among adults in England

Prior research has produced conflicting findings on the association between attention-deficit/hyperactivity disorder (ADHD) and pain, while studies among community-dwelling adults are lacking. This study examined the association between ADHD symptoms and pain in the general adult population, and the extent to which this association is influenced by comorbid common mental disorders (CMDs). Data came from the 2007 Adult Psychiatric Morbidity Survey which included a representative sample of the English adult household population aged ≥16 years (N=7403). The Adult ADHD Self-Report Scale (ASRS) Screener was used to obtain information on ADHD symptoms, while pain was assessed by the degree to which it interfered with work activity in the previous month. The Clinical Interview Schedule Revised (CIS-R) was used to evaluate six categories of CMDs. In a binary logistic regression analysis adjusted for socio-demographic factors and physical health conditions, an ADHD symptom score ≥14 was strongly associated with extreme pain (odds ratio [OR]: 3.15, 95% confidence interval [CI]: 2.09-4.74). The OR was attenuated greatly after further adjustment for CMDs (OR: 1.64, 95% CI: 1.05-2.58) but remained statistically significant. Adults with ADHD symptoms have higher odds for experiencing pain. CMDs are influential in this association but do not fully explain it.

Does environmental exposure to the greenhouse gas, N2O, contribute to etiological factors in neurodevelopmental disorders? A mini-review of the evidence

BACKGROUND

Neurodevelopmental disorders are increasing in prevalence worldwide. Previous work suggests that exposure to the environmental air pollutant and greenhouse gas - nitrous oxide (N₂O) - may be an etiological factor in neurodevelopmental disorders through the targeting of several neural correlates.

METHODOLOGY

While a number of recent systematic reviews have addressed the role of general anesthesia in the surgical setting and neurodevelopmental outcomes, a narrative mini-review was conducted to first define and characterize the relevant variables (i.e., N₂O, attention-deficit hyperactivity disorder [ADHD] and autism spectrum disorders [ASD]) and their potential interactions into a coherent, hypothesis-generating work. The narrative mini-review merges basic principles in environmental science, anesthesiology, and psychiatry to more fully develop the novel hypotheses that neurodevelopmental impairment found in conditions like ADHD and ASD may be due to exposure to the increasing air pollutant, N₂O.

RESULTS

The results of the present mini-review indicate that exposure to N₂O, even at non-toxic doses, may modulate central neurotransmission and target many neural substrates directly implicated in neurodevelopmental disorders, including the glutamatergic, opioidergic, cholinergic, and dopaminergic systems. Epidemiological studies also indicate that early and repeated exposure to general anesthesia, including N₂O, may contribute to later adverse neurodevelopmental outcomes in children.

CONCLUSIONS

The current evidence and subsequent hypotheses suggest that a renewed interest be taken in the toxicological assessment of environmental N₂O exposure using validated biomarkers and psychiatric endpoints. Given the relevance of N₂O as a greenhouse gas, societies may also wish to engage in a more robust monitoring and reporting of N₂O levels in the environment for climactic benefit as well.

Aberrant local striatal functional connectivity in attention-deficit/hyperactivity disorder

BACKGROUND

Task-based and resting-state functional Magnetic Resonance Imaging (fMRI) studies report attention-deficit/hyperactivity disorder (ADHD)-related alterations in brain regions implicated in cortico-striatal networks. We assessed whether ADHD is associated with changes in the brain's global cortico-striatal functional architecture, or whether ADHD-related alterations are limited to local, intrastriatal functional connections.

METHODS

We included a cohort of adolescents with ADHD (N = 181) and healthy controls (N = 140) and assessed functional connectivity of nucleus accumbens, caudate nucleus, anterior putamen, and posterior putamen. To assess global cortico-striatal functional architecture we computed whole-brain functional connectivity by including all regions of interest in one multivariate analysis. We assessed local striatal functional connectivity using partial correlations between the time series of the striatal regions.

RESULTS

Diagnostic status did not influence global cortico-striatal functional architecture. However, compared to controls, participants with ADHD exhibited significantly increased local functional connectivity between anterior and posterior putamen (p = .0003; ADHD: z = .30, controls: z = .24). Results were not affected by medication use or comorbid oppositional defiant disorder and conduct disorder.

CONCLUSIONS

Our results do not support hypotheses that ADHD is associated with alterations in cortico-striatal networks, but suggest changes in local striatal functional connectivity. We interpret our findings as aberrant development of local functional connectivity of the putamen, potentially leading to decreased functional segregation between anterior and posterior putamen in ADHD.

Attention-Deficit/Hyperactivity Disorder symptoms coincide with altered striatal connectivity

BACKGROUND

Cortico-striatal network dysfunction in attention-deficit/hyperactivity disorder (ADHD) is generally investigated by comparing functional connectivity of the main striatal sub-regions (i.e., putamen, caudate, and nucleus accumbens) between an ADHD and a control group. However, dimensional analyses based on continuous symptom measures might help to parse the high phenotypic heterogeneity in ADHD. Here, we focus on functional segregation of regions in the striatum and investigate cortico-striatal networks using both categorical and dimensional measures of ADHD.

METHODS

We computed whole-brain functional connectivity for six striatal sub-regions that resulted from a novel functional parcellation technique. We compared functional connectivity maps between adolescents with ADHD (N=169) and healthy controls (N=122), and investigated dimensional ADHD-related measures by relating striatal connectivity to ADHD symptom scores (N=444). Finally, we examined whether altered connectivity of striatal sub-regions related to motor and cognitive performance.

RESULTS

We observed no case-control differences in functional connectivity patterns of the six striatal networks. In contrast, inattention and hyperactivity/impulsivity symptom scores were associated with increases in functional connectivity in the networks of posterior putamen and ventral caudate. Increased connectivity of posterior putamen with motor cortex and cerebellum was associated with decreased motor performance.

CONCLUSIONS

Our findings support hypotheses of cortico-striatal network dysfunction in ADHD by demonstrating that dimensional symptom measures are associated with changes in functional connectivity. These changes were not detected by categorical ADHD versus control group analyses, highlighting the important contribution of dimensional analyses to investigating the neurobiology of ADHD.

A decade of contributions to understanding and ameliorating attention deficit-hyperactivity disorder

Background

It has been 10 years since Terje Sagvolden founded Behavioral and Brain Functions.

Body

After setting the context, this paper reviews some of the contributions of articles in the journal to the literature on ADHD over that decade. Those articles provide a cross section of some of the most important ongoing themes in ADHD research.

Conclusion

Terje’s faith in the new journal was well founded. It has survived the first threat of new journals, crib death, because of the continuing quality and relevance of the articles it carries. It has a diversified portfolio of similar research in many other fields of related interest.

[Minimal cerebral dysfunctions and ADHD in adulthood]

Attention deficit hyperactivity disorder (ADHD) is of great importance not only in children but also in adults; however, despite extensive research there are still many unsolved questions with respect to the diagnosis. Patients not only suffer from attention deficits and hyperactivity but also a variety of other problems, such as dyspraxia, problems with stimulus discrimination, dysgrammatism, legasthenia, or motor coordination problems. Furthermore, there are also psychopathological disorders, such as problems with memory, formal thinking, emotional modulation, drive and vegetative stability, in the sense of a psycho-organic syndrome. Such syndromes have long been known in psychiatry under terms, such as complex capacity disorders, minimal cerebral dysfunction (MCD), minimal brain dysfunction (MBD), mild psycho-organic syndrome, psycho-organic axis syndrome, mild cognitive impairment, developmental disorder and developmental biological syndrome. Etiological data with respect to genetics and early childhood brain trauma support the notion of a psychobiological disorder for complex cerebral dysfunction in the sense of a psycho-organic syndrome. Depending on the individual life and work situation, these additional symptoms of ADHD are in many cases of greater relevance for life adjustment than the core symptoms, depending on the individual life and work situations. The concept of minimal cerebral dysfunction describes the ADHD problem better and has a direct bearing on the diagnosis, therapy and sociomedical care of the patients.

Pain Sensitivity in Adolescent Males with Attention-Deficit/Hyperactivity Disorder: Testing for Associations with Conduct Disorder and Callous and Unemotional Traits

Background

Reduced processing and experience of aversive emotional cues is a common component of theories on the development and persistence of aggression and antisocial behaviour. Yet physical pain, arguably the most basic aversive cue, has attracted comparatively little attention.

Methods

This study measured pain sensitivity and physiological response to painful stimuli (skin conductance level, SCL) in adolescent boys with Attention-Deficit/Hyperactivity Disorder (ADHD; n = 183), who are at high risk for antisocial behaviour. We compared boys with ADHD with and without a comorbid diagnosis of Conduct Disorder (CD) on pain sensitivity, and examined patterns of association between pain measures, on the one hand, and problem severity and callous and unemotional (CU) traits, on the other.

Results

Boys with comorbid CD exhibited a higher pain threshold and tolerance than boys with ADHD alone, but the groups did not differ in physiology at the time the pain threshold and tolerance were reported. Regression analyses showed that ADHD problem severity positively predicted pain sensitivity, whereas levels of CU traits negatively predicted pain sensitivity.

Conclusions

These findings on physical pain processing extend evidence of impairments in aversive cue processing among those at risk of antisocial behaviour. The study highlights the importance of considering comorbidity and heterogeneity of disorders when developing interventions. The current findings could be used to identify subgroups within those with ADHD who might be less responsive to interventions that use corrective feedback to obtain behaviour change.

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.

Fibromyalgia patients had normal distraction related pain inhibition but cognitive impairment reflected in caudate nucleus and hippocampus during the Stroop Color Word Test

The mechanisms causing cognitive problems in chronic pain patients are not well understood. We used the Stroop color word task (SCWT) to investigate distraction-induced analgesia, cognitive performance, and cerebral activation patterns in 29 fibromyalgia (FM) patients (mean age 49.8 years, range 25–64 years) and 31 healthy controls (HC) (mean age 46.3 years, range 20–63 years). In the first study, SCWT was used to investigate distraction-induced analgesia in FM patients. Two versions of the task were applied, one with only congruent color-word images and one with incongruent images. Pressure pain thresholds were assessed using a pressure algometer before, during, and following SCWT. In the second study, reaction times (RTs) were assessed and functional magnetic resonance imaging (fMRI) was used to investigate cerebral activation patterns in FM patients and HC during the SCWT. An event-related task mixing incongruent and congruent images was used. In study one, we found reduced pressure pain sensitivity during SCWT in both groups alike and no statistically significant differences were seen between the incongruent and congruent conditions. The study two revealed longer RTs during the incongruent compared to the congruent condition in both groups. FM patients had longer RTs than HC in both conditions. Furthermore, we found a significant interaction between group and congruency; that is, the group differences in RTs were more pronounced during the incongruent condition. This was reflected in a reduced activation of the caudate nucleus, lingual gyrus, temporal areas, and the hippocampus in FM patients compared to HC. In conclusion, we found normal pain inhibition during SWTC in FM patients. The cognitive difficulties seen in FM patients, reflected in longer RTs, were related to reduced activation of the caudate nucleus and hippocampus during incongruent SCWT, which most likely affected the mechanisms of cognitive learning in FM patients.

Alterations in pain response are partially reversed by methylphenidate (Ritalin) in adults with attention deficit hyperactivity disorder (ADHD)

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is characterized by dysregulation of sensory processing and neurobiology of dopamine. Although cumulative evidence suggests that dopamine is involved in pain processing, pain perception in ADHD subjects and the effect of dopamine agonists such as methylphenidate (MP, Ritalin) on it have rarely been studied.

AIMS

The aims of this study were to (1) psychophysically assess sensitivity to pain in ADHD subjects as compared to controls and (2) examine the effects of MP on pain response in ADHD subjects.

METHODS

Thirty subjects with ADHD and 30 age- and gender-matched controls participated in a preliminary trial. Pain threshold, intensity, and tolerance in response to cold pain stimulation were measured for both groups (ADHD with no treatment). In addition, the ADHD group was reassessed following a single dose of MP treatment.

RESULTS

The ADHD subjects "without MP" in comparison with controls displayed significantly shorter cold pain threshold (2.8 ± 2.1 vs. 5.8 ± 2.5 seconds, respectively, P < 0.001) and cold tolerance (21.8 ± 22.3 vs. 62.8 ± 59.8 seconds, respectively P < 0.001). No differences in pain intensities between the groups were found. Following MP treatment, both cold threshold and tolerance in the ADHD subjects increased significantly compared to those with no treatment (3.6 ± 2.5 seconds, P = 0.011, and 46.4 ± 53.3 seconds, P < 0.001, respectively).

CONCLUSIONS

These results suggest that adults with ADHD are more sensitive to pain compared with controls and that MP may exert antinociceptive properties in these subjects. Randomized, controlled trials are warranted to verify these findings.