The Effects of Yoga on Attention, Impulsivity and Hyperactivity in Pre-school Age Children

Overview

This pilot project will evaluate yoga as an intervention to improve attention and reduce challenging behaviors such as hyperactivity and impulsivity, rated by parent and teachers, in preschool age children with or "at risk" for attention-deficit hyperactivity disorder (ADHD). "At Risk" for ADHD will be defined as four or more hyperactive/impulsive and/or inattentive symptoms on the ADHD Rating Scale IV-Preschool Version as rated by parents or teachers. Using a randomized wait-list controlled experimental design, the investigators will explore the efficacy of practicing yoga for 6 weeks on behavioral symptoms, attentional control using a computer based tasks of attention, and heart rate variability (HRV), which is a measure of self-regulatory capacity. The investigators hypothesize that practicing yoga for six weeks of will improve ADHD and other behavioral symptoms based on parent and teacher rating scales, which will correlate with improvements in scores on the computer based task of attention as well as with improvements in HRV.

Background: Symptoms of attention-deficit hyperactivity disorder (ADHD) are often observable by preschool age and can be associated with similar behavioral, social, and cognitive impairments as seen in older children with ADHD. Seventy to eighty percent of preschoolers with symptoms of ADHD continue to display these symptoms in elementary school. Behavioral therapies are recommended as first line treatments in this age group. There have been some small but promising studies looking at yoga as an intervention for school age children with ADHD, but none have looked specifically at yoga as an intervention for preschool age children with ADHD symptoms (Birdee et al, 2009). Objective: To determine if yoga improves hyperactive/impulsive symptoms and attention in preschool age children with or "at risk" for ADHD. Study design: A randomized wait-list controlled trial exploring whether 6 weeks of children's yoga improves behavioral symptoms, task-related scores of attention, and increases heart rate variability in preschool age children "at risk" for or diagnosed with ADHD. The investigators plan to enroll a total of 30 children ages 3-5 years old. "At risk" for ADHD will be defined as four or more inattentive or hyperactive/impulsive symptoms rated by parents and teachers on the ADHD Rating Scale-IV Preschool Version. Procedures: The investigators will evaluate the efficacy of yoga for improving ADHD and other behavioral symptoms using parent and teacher rating scales (ADHD Rating Scale-IV Preschool Version; Strengths and Difficulties Questionnaire), as well as objective measures including computer based tasks of attention and executive function (KiTAP, Test of Attentional Performance for Children), and heart rate variability (HRV), a physiologic measure of self-regulatory capacity. HRV will be assessed during an active, attention computer task (using the emWave ® desktop device), as well as during a relaxed state, in a breathing exercise paired with verbal affirmations. The protocol includes baseline, post-treatment and 3 month follow-up assessments. The intervention consists of school and home yoga sessions. School sessions will be held twice a week at Triumph Center for Early Childhood Education, which is a local preschool associated with University of California, Davis. The school based yoga classes will be lead by trained child yoga instructors using a manualized yoga protocol that is 30 minute long. Home session will include use of a children's yoga video featuring the same protocol to practice at home on the days that the children do not participate at school. The goal is for daily yoga practice during the 6 week intervention period. Home yoga practice will be documented daily by parents completing a brief online survey that is emailed to them. Generalization of the skills learned during the yoga sessions to behaviorally-challenging situations will be specifically developed by teaching the parents and teachers to "cue" the children to integrate skills learned in the yoga sessions into their daily routine. The goal is for the children to learn to use breathing practices and affirmations to help regain calmness and focus when their behaviors become challenging. A questionnaire will assess parent and teacher perception regarding the use of yoga in the children's daily life, its effect on challenging behaviors, and their satisfaction with the intervention. Optional focus groups will also be done with the parents and teachers of the children who participate in the study in order to gather qualitative data about the yoga intervention. Statistical Methods and Power Analysis: Outcome distributions will be visualized and, if necessary, log-transformed to reduce skewness or stabilize variances. For this wait-list design, the primary assessment of treatment effects will be estimated by comparing treatment and control groups on baseline-adjusted mean outcomes at the first follow-up and reported with 95% Confidence Intervals. Between- and within-group contrasts involving outcomes at the 2nd follow-up time will permit exploration of treatment durability. The primary index of HRV will be the standard deviation of beat-to-beat intervals, but other time- and frequency-domain indices will be evaluated in exploratory analyses. Assuming pre/post correlations of 60%, our target sample size of 30 subjects will permit estimating treatment effects with margins of error of 0.41 standard deviations and provide 80% power (with 2-sided alpha=5%) to detect between-group effects as small as 0.59 standard deviations. Gaps in knowledge: The majority of the studies on yoga for children with ADHD have been conducted in school aged children, and only one was completed in the United States. None have looked specifically at yoga as an intervention for ADHD symptoms in preschoolers. In addition, none of these studies included physiologic measures such as vagal tone, which has been shown to increase in adults who practice yoga. Physiologic measures are valuable because they are an objective measure of treatment response, may give evidence to support the role, and perhaps mechanism by which yoga may affect change in ADHD. The investigators will assess heart rate variability (HRV), a measure of the beat-to-beat changes in heart rate, which reflects the activity of the vagus nerve, a key component of the parasympathetic nervous system, which mediates changes in heart rate. Reduced HRV is associated with increased morbidity and mortality, while increased HRV is associated with physiologic resiliency, the ability to self-regulate and improved performance on tasks of executive function. Compared to healthy controls, children with ADHD have higher mean heart rates, and unmedicated children have significantly decreased HRV. In adults, HRV has been found to increase in response to both exercise and biofeedback. A study in children with ADHD evaluated the use of biofeedback using HRV coherence, synchronization of the heart rhythm pattern, and found that it improved cognitive function and behaviors. HRV has not been evaluated in relation to yoga training in young children with ADHD symptoms. Innovation: This project is novel in its subject population, preschoolers, teaching of yoga at the school, use of manualized treatments, objective measures and wait-list randomized control methodology. While there are many studies in exercise, yoga and meditation for children, many lack sophisticated methodology to guide clinical practice. The proposed methods are not highly innovative, but they are critical to moving the field forward and providing direction to clinicians, parents and teachers in need of research to guide their clinical decision-making.