Heart Rate Variability in Children with Attention-Deficit/Hyperactivity Disorder: A Pilot Study

Heart Rate Variability Biofeedback Intervention Programme to Improve Attention in Primary Schools

The importance of attentional capacity for academic performance is highlighted by the increasing demands placed on students during primary school. Between the ages of 7 and 12, there is an evolutionary improvement in attentional capacity and the school environment is considered an appropriate setting in which to develop programmes to improve attention. Heart rate variability is an appropriate indicator of attentional capacity. For all these reasons, a heart rate variability biofeedback intervention focused on breathing was developed and implemented to improve attention. The intervention consisted of two phases. In the first phase, the school teachers were trained to develop the intervention; in the second, students received five individual sessions from their teachers. In each individual session, they learned to breathe to increase their heart rate variability. A total of 272 girls and 314 boys (N = 586) aged 7-12 years participated in the programme. To study the impact of the intervention on three primary school age groups, the attention of Control and Experimental groups was assessed before and after the implementation of the programme. According to the data obtained, despite developmental improvements, the students who participated in the programme showed an increase in heart rate variability and an improvement in attentional capacity, with a greater impact on the first cycle of primary school. The usefulness of heart rate variability biofeedback interventions in improving attention in primary school is discussed and arguments for their use in children are presented.

Machine learning-enabled detection of attention-deficit/hyperactivity disorder with multimodal physiological data: a case-control study

BACKGROUND

Attention-Deficit/Hyperactivity Disorder (ADHD) is a multifaceted neurodevelopmental psychiatric condition that typically emerges during childhood but often persists into adulthood, significantly impacting individuals' functioning, relationships, productivity, and overall quality of life. However, the current diagnostic process exhibits limitations that can significantly affect its overall effectiveness. Notably, its face-to-face and time-consuming nature, coupled with the reliance on subjective recall of historical information and clinician subjectivity, stand out as key challenges. To address these limitations, objective measures such as neuropsychological evaluations, imaging techniques and physiological monitoring of the Autonomic Nervous System functioning, have been explored.

METHODS

The main aim of this study was to investigate whether physiological data (i.e., Electrodermal Activity, Heart Rate Variability, and Skin Temperature) can serve as meaningful indicators of ADHD, evaluating its utility in distinguishing adult ADHD patients. This observational, case-control study included a total of 76 adult participants (32 ADHD patients and 44 healthy controls) who underwent a series of Stroop tests, while their physiological data was passively collected using a multi-sensor wearable device. Univariate feature analysis was employed to identify the tests that triggered significant signal responses, while the Informative k-Nearest Neighbors (KNN) algorithm was used to filter out less informative data points. Finally, a machine-learning decision pipeline incorporating various classification algorithms, including Logistic Regression, KNN, Random Forests, and Support Vector Machines (SVM), was utilized for ADHD patient detection.

RESULTS

Results indicate that the SVM-based model yielded the optimal performance, achieving 81.6% accuracy, maintaining a balance between the experimental and control groups, with sensitivity and specificity of 81.4% and 81.9%, respectively. Additionally, integration of data from all physiological signals yielded the best results, suggesting that each modality captures unique aspects of ADHD.

CONCLUSIONS

This study underscores the potential of physiological signals as valuable diagnostic indicators of adult ADHD. For the first time, to the best of our knowledge, our findings demonstrate that multimodal physiological data collected via wearable devices can complement traditional diagnostic approaches. Further research is warranted to explore the clinical applications and long-term implications of utilizing physiological markers in ADHD diagnosis and management.

Reliability of an "At-Home" Method for Monitoring Resting and Reactive Autonomic Nervous System Activity in Children: A Pilot Study

BACKGROUND

Heart rate variability (HRV), an index of the functional status of the autonomic nervous system (ANS), provides an opportunity for early detection of ANS dysfunction. Lower resting, vagally related HRV parameters are associated with increased risk of physical and mental illness. External factors influencing the ANS, such as the testing environment, may impact the interpretation of HRV. This study's main aim was to determine the reliability of HRV resting and reactivity tests performed at home with children aged 4-9 years.

METHODS

Fourteen healthy children (female n = 8) aged 6.8 ± 1.5 years participated. Two HRV tests were performed at home via online supervision 7 days apart using a Polar H10 heart rate monitor. The absolute and relative reliability of the pre-exercise resting (5 min) and sub-maximal exercise step test recovery (4 × 30 s segments) HRV time and frequency domains were calculated.

RESULTS

The Pearson correlation coefficients for day 1 versus day 7 for the vagal activity HRV domains (RMSSD log) at rest and in the first 30 s and 30-60 s of recovery indicated good-to-excellent relative reliability (r > 0.8, p < 0.01). Absolute reliability was moderate for the resting RMSSD log, with a coefficient of variation (CV) of 5.2% (90% CI: 3.9, 7.8%), high for the first 30 s of standing recovery, with a CV of 10.7% (90% CI: 8.2, 15.7%), and moderate for 30-60 s of recovery, with a CV of 8.7% (90% CI: 6.6, 12.9%).

CONCLUSIONS

The findings of this pilot study indicate that the resting and exercise recovery HRV measures of vagal activity can be measured reliably at home in children. This represents a novel "at-home" protocol for monitoring ANS health and development in children.

Central Autonomic Network and heart rate variability in premature neonates

INTRODUCTION

The Central Autonomic Network (CAN) is a hierarchy of brain structures that collectively influence cardiac autonomic input, mediating the majority of brain-heart interactions, but has never been studied in premature neonates. In this study, we use heart rate variability (HRV), which has been described as the "primary output" of the CAN, and resting state functional MRI to characterize brain-heart relationships in premature neonates.

METHODS

We studied premature neonates who underwent resting state functional MRI (rsfMRI) at term, (37-weeks postmenstrual age [PMA] or above) and had HRV data recorded during the same week of their MRI. HRV was derived from continuous electrocardiogram data during the week of the rsfMRI scan. For rsfMRI, a seed-based approach was used to define regions of interest (ROI) pertinent to the CAN, and blood oxygen level-dependent signal was correlated between each ROI as a measure of functional connectivity. HRV was correlated with CAN connectivity (CANconn) for each region, and sub-group analysis was performed based on sex and clinical comorbidities.

RESULTS

Forty-seven premature neonates were included in this study, with a mean gestational age at birth of 28.1 +/- 2.6 weeks. Term CANconn was found to be significantly correlated with HRV in approximately one-fifth of CAN connections. Two distinct patterns emerged among these HRV-CANconn relationships. In the first, increased HRV was associated with stronger CANconn of limbic regions. In the second pattern, stronger CANconn at the precuneus was associated with impaired HRV maturation. These patterns were especially pronounced in male premature neonates.

CONCLUSION

We report for the first time evidence of brain-heart relationships in premature neonates and an emerging CAN, most striking in male neonates, suggesting that the brain-heart axis may be more vulnerable in male premature neonates. Signatures in the heart rate may eventually become an important non-invasive tool to identify premature males at highest risk for neurodevelopmental impairment.

Subjective and Autonomic Arousal toward Emotional Stimuli in Preadolescents with Externalizing Problems and the Role of Explicit and Implicit Emotion Regulation

Children and adolescents with externalizing problems show physiological hypo-reactivity toward affective stimuli, which may relate to their disruptive, antisocial, and thrill-seeking behaviors. This study examines differences in explicit and implicit emotion regulation between preadolescents with and without externalizing problems as well as the role of emotion regulation in subjective and autonomic responses to emotional stimuli. Preadolescents showing self- and other-reported externalizing psychopathology, and a control sample, without such difficulties, participated in a passive affective picture-viewing task with neutral, fearful, joyful, and sad images, while their heart rate and heart rate variability were measured. Participants also reported on their emotion regulation difficulties using the Difficulties in Emotion Regulation Scale. Compared to controls, youths scoring high on externalizing problems (1) reported greater emotion regulation difficulties, especially a lack of emotional clarity and difficulty in controlling impulsive actions, (2) showed higher resting heart rate variability and a lower resting heart rate, suggestive of higher emotion/autonomic regulation ability, and (3) showed both subjective and physiological hypo-arousal to emotional pictures. Heart rate variability and, to a lesser degree difficulties in emotional clarity, modulated the effects of emotional pictures on subjective and physiological arousal. Findings suggest that interventions to improve emotion regulation and awareness may help to prevent externalizing problems.

The effect of long-term use of methylphenidate on cardiac autonomic functions and ventricular arrhythmogenesis: a prospective case-control study

OBJECTIVE

We aimed to assess cardiac autonomic balance with heart rate variability by using 24-hour Holter electrocardiography and also to assess susceptibility to ventricular arrhythmias by using microvolt T wave alternance in children with attention deficit hyperactivity disorder.

METHOD

This study was conducted with age- and gender-matched groups of 40 patients taking long-acting methylphenidate for more than a year and 55 healthy controls. Heart rate variability analysis for cardiac autonomic functions and microvolt T wave alternance measurements for susceptibility to ventricular arrhythmias were evaluated by 24-hour Holter electrocardiography.

RESULTS

The mean age 10.9 ± 2.7 years, mean duration of therapy 22.76 months, and mean methylphenidate doses were 37.64 mg/day. The study group had considerably higher rMSSD, higher HF, and a lower LF/HF ratio (respectively, p : 0.02, p : 0.001 and p : 0.01). While parasympathetic activity parameters were elevated, sympathetic activity parameters were low during the sleep period. Increase in the microvolt T wave alternance values of the study group was not found to be statistically significant (p > 0.05).

CONCLUSION

In children taking long-acting methylphenidate, the autonomic balance was shown to be in favour of the parasympathetic system. Determination of the vulnerability to life-threatening ventricular arrhythmias has been evaluated for the first time in children with attention deficit hyperactivity disorder. Accordingly, microvolt T-wave alternance values give the notion that drug use is safe.

Short-term exposure to ultrafine and fine particulate matter with multipollutant modelling on heart rate variability among seniors and children from the CorPuScula (coronary, pulmonary, sanguis) longitudinal study in Germany

Background

Short-term exposure particulate matter with a diameter of 10 µm or less (PM10) and fine particulate matter (PM2.5) has been associated with heart rate variability (HRV), but exposure to ultrafine particles (UFP) has been less well examined. We investigated the associations between the HRV outcomes and short-term exposure to UFP, PM10 and PM2.5 among school-aged children and seniors.

Methods

CorPuScula (Coronary, Pulmonary and Sanguis) is a longitudinal, repeated-measure panel study conducted in 2000-2002 in Munich, Germany including 52 seniors (58-94 years old) with 899 observations and 50 children (6-10 years old) with 925 observations. A 10-min resting electrocardiogram was performed to assess resting HRV outcomes [Standard Deviation of Normal to Normal Intervals (SDNN), Root Mean Square of Successive Differences between Normal Heartbeats (RMSSD), Low Frequency power (LF), High Frequency power (HF), ration between low and high frequency (LF/HF)]. UFP and PM exposures were measured near the care home and school yard for seniors and children, respectively. Mean exposures during the day of examination (9-21 h) as well as 3-h, 12-h, 24-h, one-day, and two-day lags were assessed. Linear mixed-effect models were used to investigate the associations between short-term air pollution and HRV outcomes separately in children and seniors. The models were adjusted for sex, age, weather conditions (temperature, precipitation, and water vapor pressure), BMI, lifestyle and medical information. Two and multipollutant models adjusted for NO2 and O3 were performed.

Results

Among seniors, we observed increases in SDNN, LF, HF and LF/HF ratio after short-term exposure to UFP (hourly and daily lags) in contrast to decreases in SDNN and RMSSD after exposure to PM10. Associations were generally robust to two- and multipollutant adjustment. Among children, we observed increases of the LF/HF ratio after short-term exposures to UFP at lags 12 and 24 h. In contrast, we observed decreases of the ratio after exposure to PM2.5 and PM10. Results were largely unchanged for multipollutant modelling, however we found a more pronounced increase in SDNN and LF/HF (UFP lag 12 and 24 h) after adjusting for NO2.

Conclusions

Overall, among seniors, we observed associations of UFP and PM10 exposure with sympathetic responses of the ANS, which play an important role in sudden heart attacks or arrhythmia. Among children we found more inconsistent associations between UFP and a delayed increase in HRV. Adjusting for co-pollutants including NO2 and O3 yielded robust results.

Superior Vena Cava Flow in Children With Attention Deficit Hyperactivity Disorder

OBJECTIVE

Attention deficit/hyperactivity disorder (ADHD), whose definition, diagnosis and treatment has been the subject of debate in the scientific community for a long time, is the most common neurobehavioral disorder in childhood. There are many studies on the pathophysiology of attention deficit. However, there is no study in the literature based on direct or indirect measurement of cerebral venous circulation in ADHD, and the effect of methylphenidate (MPH) treatment on cerebral venous circulation. Therefore, it was aimed to noninvasively measure superior vena cava (SVC) flow, which is an indirect indicator of cerebral venous flow, by transthoracic echocardiography in patients with ADHD.

METHODS

In the study, 44 healthy children, and 40 ADHD patients who were planned to start on osmotic-release oral system (OROS)- MPH were included. SVC flows were measured in healthy children and before and after drug therapy of ADHD patients.

RESULTS

SVC flow was found to be higher in ADHD patients compared to healthy children. A significant decrease was found in SVC flow of ADHD patients after OROS-MPH treatment. There was no decrease in SVC flow of patients who did not respond adequately to MPH treatment.

CONCLUSION

This first study of SVC flow in children with ADHD showed that ADHD was associated with increased SVC flow and MPH treatment had a reducing effect on this increased SVC flow. We believe that noninvasive, easily measurable, and reproducible SVC flow may be a new focus of interest for future comprehensive studies as a biomarker to support clinical evaluation in the diagnosis and treatment follow-up of ADHD patients.

Effectiveness of yoga on Ewing's battery autonomic function test: cross-sectional study

INTRODUCTION

The cardiovascular autonomic functions can be tested by a Battery of five tests developed by Ewing and Clark in 1981 in Edinburgh. Yogic practices are immensely useful for physical, mental and spiritual development required for better autonomic function.

AIM AND OBJECTIVES

To assess the ANS (Autonomic function system) function with help of Ewing's Battery tests in yoga participants and healthy participants not practicing yoga.

MATERIALS AND METHODS

A cross-sectional study was conducted on 270 participants which were divided into two groups viz: 135 in healthy control (Group I) and 135 in yoga group (Group II). Subjects with informed consent between 40-50 years, were included in control (Group I) and those practicing yoga for past minimum 3 months were included in Group II. Anthropometric measurements were done and parasympathetic tests like Heart rate (HR) response to standing from the supine posture, to Valsalva maneuvers and to slow deep breathing were done. Also, sympathetic tests, Blood Pressure (BP) response to cold in cold pressor test (CPT), to sustained handgrip test and to standing from lying posture were carried out.

RESULTS

P value was found to be statically significant among yoga group as compared with healthy control group in all the sympathetic and parasympathetic tests except in CPT. As per the Ewing's criteria, normal, early, diseased and severe CAN (Cardiac autonomic neuropathy) in healthy controls findings were 11.11%, 58.51%, 37.03%, 17.77% and in yoga participants findings were 37.7%, 34.8%, 6.66% and 8.88% respectively. According to Bellavere's classification, maximum diseased CAN were found in healthy control as compared to yoga group. As per AIIMS (All India Institute of Medical Sciences) criteria, parasympathetic neuropathy was observed in 11.85% of the healthy controls and in 6.66% of the yoga group, and that maximum sympathetic neuropathy was observed in 11.11% of the healthy patients and only 3.7% of the yoga group.

CONCLUSION

More emphasis should be given on implementation of yoga from early ages at the institutional levels, hospital levels. Yoga practices will suffice and lead to improvement of unhealthy ANS condition. Overall, Yoga showed better ANS function than healthy control group.

Prenatal smoking and drinking are associated with altered newborn autonomic functions

BACKGROUND

Prenatal smoking and drinking are associated with sudden infant death syndrome and neurodevelopmental disorders. Infants with these outcomes also have altered autonomic nervous system (ANS) regulation. We examined the effects of prenatal smoking and drinking on newborn ANS function.

METHODS

Pregnant women were enrolled in Northern Plains, USA (NP) and Cape Town (CT), South Africa. Daily drinking and weekly smoking data were collected prenatally. Physiological measures were obtained during sleep 12-96 h post-delivery.

RESULTS

In all, 2913 infants from NP and 4072 from CT were included. In active sleep, newborns of mothers who smoked throughout pregnancy, compared to non-smokers, had higher breathing rates (2.2 breaths/min; 95% CI: 0.95, 3.49). Quit-early smoking was associated with reductions in beat-to-beat heart rate variability (HRV) in active (-0.08 s) and quiet sleep (-0.11 s) in CT. In girls, moderate-high continuous smoking was associated with increased systolic (3.0 mmHg, CI: 0.70, 5.24) and diastolic blood pressure (2.9 mmHg, CI: 0.72, 5.02). In quiet sleep, low-continuous drinking was associated with slower heart rate (-4.5 beat/min). In boys, low-continuous drinking was associated with a reduced ratio of low-to-high frequency HRV (-0.11, CI: -0.21, -0.02).

CONCLUSIONS

These findings highlight potential ANS pathways through which prenatal drinking and smoking may contribute to neurodevelopment outcomes.

IMPACT

In this prospective cohort study of 6985 mother-infant dyads prenatal drinking and smoking were associated with multiple ANS parameters. Smoking was associated with increased neonatal breathing rates among all infants, and heart rate variability (HRV) and blood pressure (BP) among girls. Drinking was associated with reductions in HR and BP among all newborns, and reductions in the ratio of low to-high frequency HRV among boys. These findings suggest that prenatal smoking and drinking alter newborn ANS which may presage future neurodevelopmental disorders.

Early transient dysautonomia predicts the risk of infantile epileptic spasm syndrome onset: A prospective cohort study

Background

Infantile epileptic spasm syndrome (IESS) is an age-dependent epileptic encephalopathy with a significant risk of developmental regression. This study investigates the association between heart rate variability (HRV) in infants at risk of IESS and the clinical onset of IESS.

Methods

Sixty neonates at risk of IESS were prospectively followed from birth to 12 months with simultaneous electroencephalogram (EEG) and electrocardiogram recordings for 60 min at every 2-month interval. HRV metrics were calculated from 5 min time-epoch during sleep including frequency domain measures, Poincare analysis including cardiac vagal index (CVI) and cardiac sympathetic index (CSI), and detrended fluctuation analysis (DFA α1, DFA α2). To assess the effect of each HRV metric at the 2-month baseline on the time until the first occurrence of either hypsarrhythmia on EEG and/or clinical spasm, univariate cox-proportional hazard models were fitted for each HRV metric.

Results

Infantile epileptic spasm syndrome was diagnosed in 20/60 (33%) of the cohort in a 12-month follow-up and 3 (5%) were lost to follow-up. The median age of developing hypsarrhythmia was 25 (7-53) weeks and clinical spasms at 24 (8-40) weeks. Three (5%) patients had clinical spasms without hypsarrhythmia, and 5 (8%) patients had hypsarrhythmia before clinical spasms at the initial presentation. The infants with high CSI (hazard ratio 2.5, 95% CI 1.2-5.2, P = 0.01) and high DFA α1 (hazard ratio 16, 95% CI 1.1-240, P = 0.04) at 2 months were more likely to develop hypsarrhythmia by the first year of age. There was a trend toward decreasing CSI and DFA α1 and increasing CVI in the first 8 months of age.

Conclusion

Our data suggest that relative sympathetic predominance at an early age of 2 months may be a potential predictor for developing IESS. Hence, early HRV patterns may provide valuable prognostic information in children at risk of IESS allowing early detection and optimization of cognitive outcomes. Whether early intervention to restore sympathovagal balance per se would provide clinical benefit must be addressed by future studies.

Higher scores on autonomic symptom scales in pediatric patients with neurodevelopmental disorders of known genetic etiology

INTRODUCTION

Features of underlying autonomic dysfunction, including sleep disturbances, gastrointestinal problems, and atypical heart rate, have been reported in neurodevelopmental conditions, including autism spectrum disorder (ASD). The current cross-sectional, between-groups study aimed to quantify symptoms of autonomic dysfunction in a neurodevelopmental pediatric cohort characterized by clinical diagnoses as well as genetic etiology.

METHOD

The Pediatric Autonomic Symptom Scales (PASS) questionnaire was used to assess autonomic features across a group of patients with clinical neurodevelopmental diagnoses (NPD; N = 90) and genetic etiologies. Patients were subdivided based on either having a clinical ASD diagnosis (NPD-ASD; n = 37) or other non-ASD neurodevelopmental diagnoses, such as intellectual disability without ASD, speech and language disorders, and/or attention deficit hyperactivity disorder (NPD-OTHER; n = 53). Analyses focused on characterizing differences between the NPD group compared to previously published reference samples, as well as differences between the two NPD subgroups (NPD-ASD and NPD-OTHER).

RESULTS

Our results indicate higher PASS scores in our NPD cohort relative to children with and without ASD from a previously published cohort. However, we did not identify significant group differences between our NPD-ASD and NPD-OTHER subgroups. Furthermore, we find a significant relationship between quantitative ASD traits and symptoms of autonomic function.

CONCLUSION

This work demonstrates the utility of capturing quantitative estimates of autonomic trait dimensions that may be significantly linked with psychosocial impairments and other core clinical features of ASD.

Orexin/Hypocretin System Dysfunction in ESSENCE (Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations)

Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations (ESSENCE) is an umbrella term covering a wide range of neurodevelopmental difficulties and disorders. Thus, ESSENCE includes attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and other neurodevelopmental disorders (NDDs) and difficulties, with a variety of symptoms in cognitive, motor, sensory, social, arousal, regulatory, emotional, and behavioral developmental domains, frequently co-occurring and likely having partly common neurobiological substrates. The ESSENCE concept is a clinical paradigm that promotes organizing NDDs in everyday clinical practice according to their coexistence, symptom dimensions overlapping, and treatment possibilities. Despite increased knowledge regarding NDDs, the neurobiological mechanisms that underlie them and other ESSENCE-related problems, are not well understood. With its wide range of neural circuits and interactions with numerous neurotransmitters, the orexin/hypocretin system (Orx-S) is possibly associated with a variety of neurocognitive, psychobiological, neuroendocrine, and physiological functions and behaviors. Dysfunction of Orx-S has been implicated in various psychiatric and neurological disorders. This article provides an overview of Orx-S dysfunctions' possible involvement in the development, presentation, and maintenance of ESSENCE. We provide a focused review of current research evidence linking orexin neuropeptides with specific clinical NDDs symptoms, mostly in ADHD and ASD, within the Research Domain Criteria (RDoC) framework. We propose that Orx-S dysfunction might have an important role in some of these neurodevelopmental symptom domains, such as arousal, wakefulness, sleep, motor and sensory processing, mood and emotional regulation, fear processing, reward, feeding, attention, executive functions, and sociability. Our perspective is presented from a clinical point of view. Further, more thorough systematic reviews are needed as well as planning of extensive new research into the Orx-S's role in ESSENCE, especially considering RDoC elements.

Evaluation of Sympathetic and Parasympathetic Tone and Reactivity in Adolescents with Specific Learning Disorder (Dyslexia)

OBJECTIVES

To evaluate the autonomic function in specific learning disorder (SLD) and comorbid SLD attention-deficit hyperactivity disorder (SLD-ADHD).

METHODS

A cross-sectional study was conducted in a tertiary care hospital with 20 adolescent subjects each of confirmed SLD, SLD-ADHD, and healthy control (mean age 15.32 y). Heart-rate variability and autonomic-function tests were carried out using standard protocols.

RESULTS

Heart-rate variability parameters, viz., mean RR interval, number of RR intervals which differ by ≥ 50 ms (NN50), percentage NN50, standard deviation of differences between adjacent RR intervals, root square of mean of the sum of the squares of differences between adjacent RR intervals, coefficient of variance and absolute power of high-frequency band (HF) recorded apparently lower levels in SLD and SLD-ADHD as compared to healthy control indicating lower parasympathetic tone. Whereas, higher absolute power of low- frequency band (LF) in SLD and SLD-ADHD than healthy control indicated enhanced sympathetic activity. Higher LF/HF and lower SD1/SD2 ratios in SLD and SLD-ADHD than healthy control indicated higher sympathetic tone over parasympathetic tone. Values of autonomic-function tests such as E:I ratio, change in heart rate during deep-breathing test, 30:15 ratio, and Valsalva ratio showed a decrease in SLD and SLD-ADHD as compared to healthy control implying reduction in parasympathetic reactivity. Increased values for rise in diastolic blood pressure in the isometric handgrip test and cold pressor test recorded in SLD as compared to healthy control, revealed the increased sympathetic reactivity.

CONCLUSION

Overall, results of heart-rate variability and autonomic-function tests imply dysregulation of sympathetic and parasympathetic activities with sympathetic dominance in SLD and SLD-ADHD.

Cardiac Evaluation of Exercise Testing in a Contemporary Population of Preschool Children: A New Approach Providing Reference Values

The objective of this study was to evaluate cardiac autonomic function at rest, during maximal exercise, and in post-exercise recovery, to determine sex-specific and age-specific differences in resting heart rate (RHR), linear and spectral parameters of Heart Rate Variability (HRV), HR_peak, and heart rate recovery (HRR) after one and five minutes, in preschool children. This study involved a cohort of 167 healthy children (79 girls) aged 3 to 6 years that were selected from several schools in southern Spain. A 10 × 20 m test was conducted, and the cardiovascular response was recorded. No significant differences were found in all variables between the sexes. However, a significant reduction in RHR and an increase in HRR were found from age 4 to age 6. HRV parameters at rest were higher in older children. No associations between 10 × 20 m performance, weight status, and cardiac parameters were found. Simple linear regression analysis revealed that heart rate reserve (HRr), HRR_5min, RMSSD, and HF were the variables that showed association with all HR parameters. There was also a significant correlation between HRr and HRR_5min. In conclusion, cardiovascular autonomic function during rest, exercise, and recovery in Spanish preschool children was not influenced by sex, although older children showed greater cardiovascular modulation. Cardiorespiratory fitness status was not associated with HR response.

EPSPatNet86: eight-pointed star pattern learning network for detection ADHD disorder using EEG signals

Objective.The main objective of this work is to present a hand-modelled one-dimensional signal classification system to detect Attention-Deficit Hyperactivity Disorder (ADHD) disorder using electroencephalography (EEG) signals.Approach.A novel handcrafted feature extraction method is presented in this research. Our proposed method uses a directed graph and an eight-pointed star pattern (EPSPat). Also, tunable q wavelet transforms (TQWT), wavelet packet decomposition (WPD), statistical extractor, iterative Chi2 (IChi2) selector, and the k-nearest neighbors (kNN) classifier have been utilized to develop the EPSPat based learning model. This network uses two wavelet decomposition methods (TQWT and WPD), and 85 wavelet coefficient bands are extracted. The proposed EPSPat and statistical feature creator generate features from the 85 wavelet coefficient bands and the original EEG signal. The learning network is termed EPSPatNet86. The main purpose of the presented EPSPatNet86 is to detect abnormalities of the EEG signals. Therefore, 85 wavelet subbands have been generated to extract features. The created 86 feature vectors have been evaluated using the Chi2 selector and the kNN classifier in the loss value calculation phase. The final features vector is created by employing a minimum loss-valued eight feature vectors. The IChi2 selector selects the best feature vector, which is fed to the kNN classifier. An EEG signal dataset has been used to demonstrate the presented model's EEG signal classification ability. We have used an ADHD EEG dataset since ADHD is a commonly seen brain-related ailment.Main results.Our developed EPSPatNet86 model can detect the ADHD EEG signals with 97.19% and 87.60% accuracy using 10-fold cross and subject-wise validations, respectively.Significance.The calculated results demonstrate that the presented EPSPatNet86 attained satisfactory EEG classification ability. Results show that we can apply our developed EPSPatNet86 model to other EEG signal datasets to detect abnormalities.

Automated classification of attention deficit hyperactivity disorder and conduct disorder using entropy features with ECG signals

BACKGROUND

The most prevalent neuropsychiatric disorder among children is attention deficit hyperactivity disorder (ADHD). ADHD presents with a high prevalence of comorbid disorders such as conduct disorder (CD). The lack of definitive confirmatory diagnostic tests for ADHD and CD make diagnosis challenging. The distinction between ADHD, ADHD + CD and CD is important as the course and treatment are different. Electrocardiography (ECG) signals may become altered in behavioral disorders due to brain-heart autonomic interactions. We have developed a software tool to categorize ADHD, ADHD + CD and CD automatically on ECG signals.

METHOD

ECG signals from participants were decomposed using empirical wavelet transform into various modes, from which entropy features were extracted. Robust ten-fold cross-validation with adaptive synthetic sampling (ADASYN) and z-score normalization were performed at each fold. Analysis of variance (ANOVA) technique was employed to determine the variability within the three classes, and obtained the most discriminatory features. Highly significant entropy features were then fed to classifiers.

RESULTS

Our model yielded the best classification results with the bagged tree classifier: 87.19%, 87.71% and 86.29% for accuracy, sensitivity and specificity, respectively.

CONCLUSION

The proposed expert system can potentially assist mental health professionals in the stratification of the three classes, for appropriate intervention using accessible ECG signals.

Evaluation of Mindfulness State for the Students Using a Wearable Measurement System

Purpose

This study aimed to develop and evaluate the feasibility and preliminary efficiency of a methodology to measure the mindfulness state using a wearable device ("Cap") capable of monitoring students' levels of full attention by means of real-time measured heart rate variability (HRV).

Methods

The device was developed to export the data to the user's smartphone via Bluetooth, which in turn stores the securely accessible data in the cloud. The autonomous wearable device consists of electronic boards of the Arduino platform that detect the period in milliseconds between two subsequent referential R peaks of the QRS complex wave through infrared oxygenation sensor.

Results

In a population of 13 subjects (8 female, 5 male, age 16.1 years ± 0.58 ), the Z-test ( p < 0.05 ) using rMSSD (root mean squared successive differences) and the Toronto Mindfulness (Curiosity) Scale within two 50 min windows, shows that increased HRV values converge to high values for the mindfulness state when the time difference between R n and R n + 1 samples is greater than 88 ms.

Conclusion

The device proved to be viable and potentially effective for measuring the state of mindfulness. Thus, further studies should be conducted to test it on a large scale as well as in real classroom situations.

Omega-3 Rich Oils Attenuate ADHD-Like Behaviour Induced by Dietary Monosodium Glutamate in Rats

&lt;b&gt;Background and Objective:&lt;/b&gt; Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, hyperactivity and cognitive dysfunction. The present study was designed to examine the possible modulatory effect of Fish, Walnuts or Fenugreek Oils against Attention Deficit Hyperactivity Disorder (ADHD)-like Behavior induced by Monosodium Glutamate (MSG) in Rats. &lt;b&gt;Materials and Methods:&lt;/b&gt; Fifty weaning rats were divided into five groups, (each group contain 10 rats) as follows: Group 1: Normal control rats were fed on a balanced diet. Groups from 2-5 rats were fed on a balanced diet+MSG (0.4 g kg&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt; diet), Group 2 served as a positive control group whereas group 3, 4 and 5 treated with Fish, Walnuts and Fenugreek oil, respectively, (200 mg kg&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt; b.wt.) by intra-gastric tube. Biochemical and behavioural parameters were tested as well as microscopic examination of brain tissue was done. &lt;b&gt;Results:&lt;/b&gt; MSG ingestion caused marked disruption in locomotors activity, memory function and brain tissue structure along with significant abnormalities in some bio-markers and reduction in the gene expression level of Bcl-2 in brain tissue. However, treatment with the tested oils showed remarkable effect by reversing the condition. &lt;b&gt;Conclusion:&lt;/b&gt; Dietary supplementation with walnut; fenugreek or fish oils at the tested dose could modulate the condition of ADHD in rats.

Is Low Heart Rate Variability Associated with Emotional Dysregulation, Psychopathological Dimensions, and Prefrontal Dysfunctions? An Integrative View

Several studies have suggested a correlation between heart rate variability (HRV), emotion regulation (ER), psychopathological conditions, and cognitive functions in the past two decades. Specifically, recent data seem to support the hypothesis that low-frequency heart rate variability (LF-HRV), an index of sympathetic cardiac control, correlates with worse executive performances, worse ER, and specific psychopathological dimensions. The present work aims to review the previous findings on these topics and integrate them from two main cornerstones of this perspective: Porges' Polyvagal Theory and Thayer and Lane's Neurovisceral Integration Model, which are necessary to understand these associations better. For this reason, based on these two approaches, we point out that low HRV is associated with emotional dysregulation, worse cognitive performance, and transversal psychopathological conditions. We report studies that underline the importance of considering the heart-brain relation in order to shed light on the necessity to implement psychophysiology into a broader perspective on emotions, mental health, and good cognitive functioning. This integration is beneficial not only as a theoretical ground from which to start for further research studies but as a starting point for new theoretical perspectives useful in clinical practice.

Animal models of attention-deficit hyperactivity disorder (ADHD)

Attention-deficit hyperactivity disorder (ADHD) is a heterogeneous neuropsychiatric disorder characterized by three primary symptoms hyperactivity, attention deficit, and impulsiveness, observed in both children and adults. In childhood, this disorder is more common in boys than in girls, and at least 75% will continue to suffer from the disorder until adulthood. Individuals with ADHD generally have poor academic, occupational, and social functioning resulting from developmentally inappropriate levels of hyperactivity and impulsivity, as well as impaired ability to maintain attention on motivationally relevant tasks. Very few drugs available in clinical practice altogether abolish the symptoms of ADHD, therefore, to find new drugs and target it is essential to understand the neuropathological, neurochemical, and genetic alterations that lead to the progression of ADHD. With this contrast, an animal study is the best approach because animal models provide relatively fast invasive manipulation, rigorous hypothesis testing, as well as it provides a better angle to understand the pathological mechanisms involved in disease progression. Moreover, animal models, especially for ADHD, serve with good predictive validity would allow the assessment and development of new therapeutic interventions, with this aim, the present review collect the various animal models on a single platform so that the research can select an appropriate model to pursue his study.

Child-parent cardiac transference is decreased following disrupted/absent early care

Parental input shapes youth self-regulation development, and a lack of sensitive caregiving is a risk factor for youth mental health problems. Parents may shape youth regulation through their influence over biological (including neural) and behavioral development during childhood at both micro (moment-to-moment) and macro (global) levels. Prior studies have shown that micro-level parent-child interactions shape youth's biology contributing to youth mental health. However, it remains unclear whether prior disrupted/absent care affects those moment-to-moment parent-youth interactions in ways that increase risk for youth psychopathology. In the current study, we calculated transfer entropy on cardiac data from parent-youth dyads where the youth had either been exposed to disrupted care prior to adoption or not. Transfer Entropy (TE) tracks information flow between two signals, enhancing quantification of directional coupling, allowing for the examination of parent-child and child-parent influences. Using this novel approach, we identified lower cardiac information transfer from youth-to-parents in dyads where the youth had been exposed to disrupted/absent early care. Moreover we showed that the degree to which the parent's physiology changed in response to youth's physiology was negatively related to the youth's mental health, representing a potential pathway for elevated mental health risk in populations exposed to disrupted/absent early care.

Paternal antisociality and growth in child delinquent behaviors: Moderating effects of child sex and respiratory sinus arrhythmia

Children of fathers with antisocial personality disorder (ASPD) are at risk for developing delinquency, and both biological and environmental mechanisms contribute. In this study, we test parasympathetic nervous system (PNS) function as a vulnerability/sensitivity attribute in predicting intergenerational associations between fathers' antisociality and children's delinquency scores. We followed 207 children (ages 8-12 years at intake; 139 boys) across three annual assessments. Fathers' antisociality was measured via maternal reports on the Family Interview for Genetic Studies (FIGS). At Year 1, children's resting respiratory sinus arrhythmia (RSA) was measured. At Years 1, 2, and 3, child delinquent behaviors were assessed using the delinquency subscale of the Youth Self-Report. At age 8, boys' delinquency scores were associated weakly with paternal antisocial behaviors. However, boys' delinquency scores increased steeply thereafter specifically for those who had fathers with higher antisocial symptoms. In addition, associations between delinquency and paternal antisociality were largest for boys with higher resting RSA. For girls, growth in delinquency was unrelated to both father antisociality and resting RSA. These findings (a) suggest moderating effects of children's age, sex, and PNS function on associations between father antisocial behavior and offspring delinquency; and (b) provide insights into differential vulnerability among children of fathers with ASPD.

Measuring Heart Rate Variability Using Commercially Available Devices in Healthy Children: A Validity and Reliability Study

Heart rate variability (HRV) is an accepted method for determining autonomic nervous system activity and cardiovascular risk in various populations. This study assessed the validity and reliability of a commercially available finger photoplethysmography (PPG) system for measuring pediatric HRV in a real-world setting. Sixteen healthy children (4.06 ± 0.58 years) were recruited. The PPG system was compared to the Polar H10 heart rate (HR) sensor validated against ECG (gold standard) for HRV measurement. Seated short-term resting R-R intervals were recorded simultaneously using both systems. Recordings were performed on 3 days at the participants’ school. Paired t-tests, effect sizes and Bland–Altman analyses determined the validity of the PPG system. The relative and absolute reliability of both systems were calculated. No HRV parameters were valid for the PPG system. Polar H10 yielded moderate (0.50–0.75) to good (0.75–0.90) relative reliability with R-R intervals and the standard deviation of instantaneous and continuous R-R variability ratio showing the best results (ICCs = 0.84). Polar H10 displayed better absolute reliability with the root mean square of successive differences, R-R intervals and HR showing the lowest values (TEM% < 12%). The use of the Polar H10 and not the PPG system is encouraged for HRV measurement of young children in an educational real-world setting.

Z-Score Neurofeedback and Heart Rate Variability Training for Adults and Children with Symptoms of Attention-Deficit/Hyperactivity Disorder: A Retrospective Study

ADHD is a common condition that causes suffering for those affected and economic loss for society at large. The current standard treatment for ADHD includes stimulant medications, which are not effective for all patients, may include side effects, and can be non-medically misused. Z-score neurofeedback (NFB) and heart rate variability (HRV) biofeedback are alternative treatment strategies that have been associated with Attention-Deficit/Hyperactivity Disorder (ADHD) symptom improvement. We utilized a retrospective pre-post study design to quantify the change in clients' ADHD symptoms after combined NFB + HRV treatment (which included simultaneous z-score training at four sites). We also assessed whether relevant physiological measures changed in accordance with the protocol, which would be consistent with effective NFB + HRV training. Adults (n = 39) and children (n = 100) with Borderline or Clinical ADHD classifications by the Achenbach System of Empirically Based Assessment (ASEBA) received 30 sessions of NFB + HRV training. Measures were compared before and after treatment for the ASEBA, the Integrated Visual and Auditory Continuous Performance Test (IVA), ADHD medication use, HRV and breathing parameters, and quantitative electroencephalogram (QEEG) parameters. Average ASEBA Attention-Deficit/Hyperactive Problems score improved after treatment for adults and children (p < 0.0001), with Cohen effect sizes (dz) of -1.21 and -1.17, respectively. 87.2% of adults and 80.0% of children experienced improvements of a magnitude greater than or equal to the Minimal Clinically Important Difference. After treatment, 70.8% of adults and 52.8% of children who began in the ASEBA Clinical range, and 80.0% of adults and 63.8% of children who began in the ASEBA Borderline range, were classified in the Normal range. IVA scores also improved after treatment. Changes in HRV and breathing pattern after treatment were consistent with the protocol. QEEG parameters after treatment were closer to the age-based normative mean, which is consistent with effective z-score NFB training.

Effects of manual cranial therapy on heart rate variability in children without associated disorders: Translation to clinical practice

BACKGROUND

and purpose: Heart rate variability (HRV) represents a marker of autonomic activity, self-regulation and psychiatric illness. Few studies of manual therapy have investigated the neurophysiological effects of manual cranial therapy (MC-t). This study assessed the neurophysiological short/medium-term effects of two manual therapy interventions: massage therapy (Mss-t) and MC-t.

MATERIALS AND METHODS

A double-blind clinical trial was conducted with 50 healthy children, randomized into two groups who received a Mss-t intervention or MC-t. The variables analysed included vital signs (temperature, respiratory rate, heart rate, blood pressure) and HRV components, including the root mean square of successive differences (RMSSD), high frequency (HF), low frequency (LF) and LF/HF ratio.

RESULTS

Both interventions produced short-term parasympathetic effects, although the effects of MC-t were more persistent.

CONCLUSION

The persistence of the MC-t intervention suggested a prominent vagal control and better self-regulation. Autonomic imbalances in mental pathologies may benefit from the neurophysiological effects of MC-t.

Resting heart rate variability, attention and attention maintenance in young adults

Heart rate variability (HRV) is a widely used measure that reflects autonomic (parasympathetic) control of the heart. HRV has been linked with attentional performance, but it is unclear to what extent resting HRV is associated with both attention and attentional maintenance. In order to address this, we calculated HRV in seventy-four young and healthy volunteers (43 men, age: 21.6 ± 2.4), who completed the D2 Test of Attention (D2), which was used to calculate an index of Concentration Performance (CP) and a measure of attention maintenance, the coefficient of variation (CV). After accounting for the effects of sex and age on HRV, there was no significant association between HRV and CP (p = .2), but a significant relationship between HRV and CV (p = .03). Overall, our study demonstrates that attention maintenance, but not attentional performance, is associated with higher resting state HRV which suggests that attentional performance from D2 subtest-to-subtest may reflect HRV's facilitation of behaviour flexibility.

Pupillary Light Reflex in Children with ADHD

Attention deficit/hyperactivity disorder (ADHD) is one of the most frequently seen mental disorders in children with an increasing risk for other mental disorders. ADHD represents a primary biological dysfunction of the central nervous system, such as dysregulation of frontal-subcortical-cerebellar catecholaminergic circuits and imbalances in the dopaminergic system. However, autonomic nervous system, comprised of two primary branches - sympathetic and parasympathetic nervous systems that are normally in dynamic balance, plays an essential role in the regulation of body functions. Although it is generally assumed that the autonomic regulation is impaired during ADHD the information related to this dysregulation is limited. One of the options to observe changes of autonomic balance in ADHD is pupillary light reflex (PLR). Pupillometric evaluation can be used for the assessment of functioning of both autonomic nervous system branches and certain parameters of pupil responsivity can be helpful as a tool for medical diagnostic and treatment. In conclusion, these findings suggest the pupillometry as a non-invasive method that can indicate abnormalities in the complex central autonomic network regulating PLR.

Child's buccal cell mitochondrial DNA content modifies the association between heart rate variability and recent air pollution exposure at school

BACKGROUND

Studies investigating short-term exposure to ambient air pollution and heart rate variability (HRV) suggest that particulate matter (PM) exposure is associated with reductions in measures of HRV. Mitochondria are sensitive to PM exposure and may represent a biologically relevant underlying mechanism. However, evidence in children is lacking.

OBJECTIVES

Here we examine whether PM has an influence on children's HRV and evaluate whether mitochondrial DNA content (mtDNAc) reflects individual susceptibility.

METHODS

Within a panel study in primary school children (aged 9-12 years), we measured HRV in a subset of 60 children on three different days during school-time using four indicators: normal-to-normal intervals (SDNN), square root of mean squared difference of normal-to-normal intervals (rMSSD), high frequency (HF), and low frequency (LF). This resulted in a total number of 150 visits (median number of visits per child: 2.5/child). MtDNAc was measured using qPCR in buccal cells. We measured recent PM exposure at the school. Residential 24-hour mean exposure to PM was modelled with a high resolution spatial temporal model. Mixed-effects models were used to estimate the association between HRV and recent PM exposure and potential effect-modification by mtDNAc.

RESULTS

Children were on average [SD] 9.9 [1.2] years and comprised 39 girls. Median [25th-75th] recent outdoor PM_2.5 and PM₁₀ exposure at school was 6.20 [2.8-12.8] μg/m³ and 29.3 [24.7-42.0] μg/m³, respectively. In children with low mtDNAc (25th percentile), we observed for each 10 μg/m³ increment in recent PM_2.5 exposure a lowering in the LF parameter with 9.76% (95% CI: -16.9 to -1.99%, p = 0.02; p_int = 0.007). Children with high mtDNAc did not show this association. For PM₁₀ exposure, we observed an inverse association with three HRV indicators in children with low mtDNAc: -2.24% (95% CI: -4.27 to -0.16%; p = 0.04; p_int = 0.02) for SDNN, -5.67% (95% CI: -10.5 to -0.59%; p = 0.03; p_int = 0.04) for HF and -6.64% (95% CI: -10.7 to -2.38%; p = 0.003; p_int = 0.005) for LF.

CONCLUSIONS

HRV is inversely associated with recent PM air pollution, especially in children with low mtDNAc. Our data revealed that mtDNAc determines susceptibility to adverse autonomic effects of recent PM exposure in children.

Correlation between Heart Rate Variability and Bladder Sensations During Filling and Voiding Phase of Urodynamic Study in Patients with Myelopathy

Objective:

The objective of this study was to correlation between heart rate variability (HRV) and bladder sensations during filling and voiding phase of urodynamic study (UDS) in patients with myelopathy.

Materials and Methods:

Myelopathy patients (traumatic and nontraumatic) within 6 months of illness were included in the study. Demographic data, etiopathological diagnosis, and urinary complaints were noted. UDS was performed and simultaneous HRV calculated at each event of filling and voiding phase by recording and calculating standard deviation of normal-to-normal (NN) interval (SDNN), root mean square of successive differences, total power (TP), average heart rate, high frequency (HF), low-frequency (LF) ratio, and data analyzed.

Results:

The study included 30 patients (23 males) with a mean age of 31.2 years (range 18–60 years, standard deviation 11.6). The mean of LF in normalized units showed an increase from 43.6 ± 14.1 at baseline to 48.9 ± 17.4 at strong desire to void (SDV) and at urgency to 44.1 ± 14.5. HF at baseline 40.4 ± 14.1 reduced to 36.4 ± 12.8 at SDV and rose at urgency to 41.2 ± 13.2. LF/HF at baseline was 1.3 ± 0.8, which increased to 1.6 ± 1.1 at SDV and reduced at urgency to 1.2 ± 0.6. Significant change in mean value was seen in TP (P = 0.01) and SDNN (P = 0.009) at first desire to void. Significant positive trend was seen in TP (P = 0.048) and SDNN (P = 0.042) during filling.

Conclusion:

Comparison of HRV measures failed to show significant rise in sympathetic or parasympathetic component in myelopathy patients during UDS and requires more critical evaluation.

Brain-heart interaction in perseverative cognition

The move from the concept of homeostasis to that of allostasis has led reactivity stress research to widen the object of its investigation: from the brief physiological response that occurs when one is facing a stressor to what happens when one is anticipating or recovering from a stressor. A paradigmatic example is represented by perseverative cognition, during which human beings react "as if" they were constantly facing a concrete stressor. The core idea behind this review is that the cognitive inflexibility that characterizes perseverative cognition is reflected in both our body (by increased autonomic nervous system rigidity assessed by heart rate variability; HRV) and our brain (by reduced prefrontal-amygdala functional connectivity). This is a review of studies conducted in different settings (laboratory, daily life), populations (healthy, major depression, generalized anxiety), location (United States, Europe), and age groups (children, adults) that consistently replicated the association between autonomic, subjective, and behavioral measures of cognitive inflexibility during perseverative cognition. Moreover, compelling neuroimaging data suggest that HRV reduction from pre- to post-induction of perseverative cognition is associated with both structural and functional brain abnormalities reflecting impaired prefrontal inhibitory control over subcortical structures (e.g., diminished prefrontal-amygdala functional connectivity). The integration of neuroscience techniques with clinical autonomic research has advanced our understanding of the neurobiology of brain-heart interaction during perseverative cognition, potentially yielding to more effective treatment packages. This is clinically relevant if one considers that perseverative cognition is a pervasive transdiagnostic factor that carries prognostic risk for both psychological and somatic health.

Mind-Body Therapy for Children with Attention-Deficit/Hyperactivity Disorder

Attention-deficit/hyperactivity disorder (ADHD) is pervasive among the pediatric population and new treatments with minimal adverse effects are necessary to be studied. The purpose of this article is to review current research studying mind–body therapies for treatment of children diagnosed with ADHD. Literature was reviewed pertaining to the effectiveness of movement-based therapies and mindfulness/meditation-based therapies for ADHD. Many positive effects of yoga, Tai Chi, physical activity, and meditation may significantly improve symptoms of ADHD among children.

Blood pressure and anthropometry in children treated with stimulants: a longitudinal cohort study with an individual approach

BACKGROUND

Knowledge about the long-term effects on blood pressure (BP) and body mass index (BMI) when treating young patients for attention-deficit/hyperactivity disorder (AD/HD) with stimulants is limited. Most of the studies have reported mean and not individual values for anthropometrics and BP in treatment with stimulants. This seems to be the first study of changes based on the analyses of individual data measured over time.

PATIENTS AND METHODS

Seventy young patients (aged 8-18 years) diagnosed with AD/HD and responding well to treatment with stimulants were followed for a mean period of 3 years and 3 months. BP, heart rate, height, weight, and BMI were transformed to standard deviations or z-scores from before treatment to the last registered visit.

RESULTS

The mean dose of methylphenidate was 0.95 mg/kg. The mean increase of systolic and diastolic BP was 0.4 z-score and 0.1 z-score, respectively. The systolic BP was associated with BMI; a higher BMI at baseline increased the risk for an increase in systolic BP. Ten percent of the total group had a weight at follow-up of <-1.5 standard deviation (SD) and 12% had a height of <-1.5 SD. Mean height at follow-up was -0.2 SD, but 40% had a reduced height of at least 0.5 SD during the treatment period. BMI on a group level was reduced from +0.8 SD to +0.3 SD. Of the 19 patients with a BMI >+1.5 SD at baseline, 50% had a significantly reduced BMI.

CONCLUSION

Consequences of stimulant treatment must be evaluated individually. Besides significant effects on core AD/HD symptoms, some patients have lower BMI and BP and some increase/maintain their BMI and/or increase their systolic BP. The risk of reduced height trajectory needs further research.