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Early television exposure and subsequent attentional problems in children
CURRENT BEST EVIDENCE
CLINICAL RESEARCH ABSTRACTS FOR PEDIATRICIANS EDITOR’S NOTE: Journals reviewed for this issue: Archives of Disease in Childhood, Archives of Pediatrics and Adolescent Medicine, British Medical Journal, Journal of the American Medical Association, Journal of Pediatrics, The Lancet, New England Journal of Medicine, Pediatric Infectious Diseases Journal, and Pediatrics. Gurpreet K. Rana, BSc, MLIS, Taubman Medical Library, University of Michigan, contributed to the review and selection of this month’s abstracts. —John G. Frohna, MD, MPH
Early television exposure and subsequent attentional problems in children
potential mechanisms underlying this relationship, and the effects of various types of programming content.
Christakis DA, Zimmerman FJ, DiGiuseppe DL, McCarty CA. Pediatrics 2004;113:708-13
Neuroscience confirms the power of environmental experiences in shaping the developing brain. Repeated exposure to any stimulus in a child’s environment may forcibly impact mental and emotional growth, either by activity-induced growth (‘‘wiring by firing’’) or by neural pruning of neglected potential (‘‘use it or lose it.’’).1 These shaping processes, affecting structure and function, involve both cellular development and neurotransmitter regulation. Although little developmental research has specifically targeted attention systems, which include interlocking feed-forward and feedback loops and associated catecholamine neurotransmitters in prefrontal and subcortical areas,2 there is every reason to believe that their gradual maturation implies a degree of malleability. Interesting unanswered questions are to what degree catecholamine mechanisms, implicated in stimulusseeking and addictive behaviors as well as in attention disorders, can be ‘‘set’’ by childhood experiences such as exposure to arousing types of electronic media, or whether insistent noise of television in the home may interfere with the development of ‘‘inner speech,’’ by which a child learns to think through problems and plans and restrain impulsive responding.
Context Cross-sectional research has suggested that television viewing may be associated with decreased attention spans in children. However, longitudinal data of early television exposure and subsequent attentional problems have been lacking. Objective To test the hypothesis that early television exposure (at ages 1 and 3) is associated with attentional problems at age 7. Design Longitudinal population survey, using data from the National Longitudinal Survey of Youth. Participants More than 11,000 children of a nationally representative sample. Main outcome measure The hyperactivity subscale of the Behavioral Problems Index determined on all participants at age 7. Children who were $1.2 SD above the mean were classified as having attentional problems. The main predictor was hours of television watched daily at ages 1 and 3 years.
Conclusions Early television exposure is associated with attentional problems at age 7. Efforts to limit television viewing in early childhood may be warranted, and additional research is needed.
Research has clearly demonstrated a genetic component in attention deficit-hyperactivity disorder (ADHD)3; current treatments emphasize well-advertised drugs that purport to normalize catecholamine (dopamine, norepinephrine) function.4 Often dramatic improvement is seen on a drug regimen, so writing a prescription is an obvious choice for overscheduled physicians. Yet the contribution of environmental factors to attention disorder has barely been touched by systematic research. This study’s indication that an omnipresent environmental agent is associated with ADHD suggests that early preventive efforts should also be emphasized.
Comment The provocative findings by Christakis et al are long overdue. The researchers’ systematic approach, wide variety of variables, and group size all lend credibility and create a new imperative for follow-up investigations quantifying more specifically the diagnosis of ‘‘attentional problem,’’
A recent survey found that 43% of children aged 2 and younger watch television everyday, and 26% have a television in their bedrooms. The study also showed 68% of children under the age of 2 spend slightly more than 2 hours per day using screen media.5
Results Data were available for 1278 children at age 1, and 1345 children at age 3; 10% of children had attentional problems at age 7. In a logistic regression model, hours of television viewed per day at both ages 1 and 3 was associated with attentional problems at age 7 (1.09 [1.03–1.15] and 1.09 [1.02–1.16]), respectively.
Clinical Research Abstracts for Pediatricians
679
Now that we have an ‘‘epidemic’’ of ADHD, it is indeed time to ask the research questions so ably initiated by Christakis et al and to consider pediatricians’ responsibility in educating parents about placing limits on ‘‘screen time.’’
Jane M. Healy, PhD Vail, CO 81657
REFERENCES 1. LeDoux J. Synaptic self. New York: Viking/Penguin; 2002. 2. Solitano MV, Arnsten AFT, Castellanos FX, eds. Stimulant drugs and ADHD: basic and clinical neuroscience. Oxford (UK): Oxford University Press; 2001. 3. Barkley RA. Attention-deficit hyperactivity disorder: a handbook for diagnosis and treatment. 2nd ed. New York (NY): Guilford; 1998. 4. ADHD and executive functions: impact of age, gender, and new treatment options. Seminar sponsored by Eli Lilly and Co. Presented at the 111th Annual Convention of the American Psychological Association, August 9, 2003, Toronto, Ontario, Canada. 5. Rideout VJ, Vandewater EA, Wartella EA. Zero to six: electronic media in the lives of infants, toddlers, and preschoolers. Publication no. 3378. Menlo Park (CA): Kaiser Family Foundation; 2003.
Preventing childhood obesity by reducing consumption of carbonated drinks: Cluster randomised controlled trial
and its effect on obesity. Although the results of this intervention showed modest changes in soda consumption, there did appear to be a notable reduction in the number of obese and overweight children. There were several limitations to this study. Although the classes within a school were randomized, there was a risk of cross-contamination between classes. There may be some response bias, as only a small percentage of diaries were completed (36%). The authors addressed this, noting that the rates of obesity were the same in responders and nonresponders. They also state the baseline consumption of soda was the same in the two groups. The fact the diaries were only collected for a three-day period further limits the results, as this may not be a true indicator of the child’s average soda consumption. Despite these limitations, this study provides hope that interventions targeting single variables may be successful in limiting obesity, and it draws our attention to the significant contribution soda consumption has on childhood obesity. Parents and schools may be overwhelmed with messages regarding diet, nutrition, and exercise. This intervention gives parents and children a specific goal, to decrease soda consumption, with the benefit of weight reduction. The fact that this intervention requires little teacher or school training and can be provided with relative ease makes it even more appealing.
James J, Thomas P, Cavan D, Kerr D. BMJ 2004;328:1237-42 Context Obesity in children seems to be related to the consumption of sugar-sweetened carbonated drinks. Objective To determine if a school-based educational program aimed at reducing consumption of carbonated drinks can prevent excessive weight gain in children. Design Cluster randomized controlled trial. Setting
Six primary schools in southwest England.
Participants
644 children aged 7-11 years.
Interventions Focused educational program on nutrition throughout one school year. Main outcome measures Drink consumption and number of overweight and obese children. Results Consumption of carbonated drinks over 3 days decreased by 0.6 glasses (average glass size 250 ml) in the intervention group but increased by 0.2 glasses in the control group (mean difference 0.7; 95% CI, 0.1-1.3). At 12 months the percentage of overweight and obese children increased in the control group by 7.5% compared with a decrease in the intervention group of 0.2% (mean difference 7.7%, 2.2-13.1). Conclusions A targeted, school based education program produced a modest reduction in the number of carbonated drinks consumed, which was associated with a reduction in the number of overweight and obese children. Comment While multivariable intervention programs have shown minimal effects on rates of obesity,1,2 this study focused on a single variable, the consumption of carbonated beverages,
680
Clinical Research Abstracts for Pediatricians
Heather Van Mater, MD Department of Pediatrics, University of Michigan Ann Arbor, MI 48109
REFERENCES 1. Atkinson RL, Nitzke SA. School based programmes on obesity. BMJ 2001;323:1018-9. 2. Sahota P, Rudolf MCJ, Dixey R, Hill AJ, Barth JH, Cade J. Evaluation of implementation and effect of primary school based intervention to reduce risk factors of obesity. BMJ 2001;323:1027-9.
A comparison of high-dose and standard-dose epinephrine in children with cardiac arrest Perondi MB, Reis AG, Paiva EF, Nadkarni VM, Berg RA. N Engl J Med 2004;350:1722-30 Context When efforts to resuscitate a child after cardiac arrest are unsuccessful despite the administration of an initial dose of epinephrine, American Heart Association guidelines recommend that the next dose of epinephrine (ie, the rescue dose) should be the same (standard) dose or a higher dose. Objectives To evaluate whether rescue therapy with highdose epinephrine compared with continued use of the standard dose, would improve the rate of survival at 24 hours for children who had an in-hospital cardiac arrest. Design Prospective, randomized, double-blind trial. Setting Children’s Institute of the University of S~ ao Paulo School of Medicine, a tertiary-care children’s hospital that admits more than 6000 patients each year.
The Journal of Pediatrics November 2004
CLINICAL RESEARCH ABSTRACTS FOR PEDIATRICIANS EDITOR’S NOTE: Journals reviewed for this issue: Archives of Disease in Childhood, Archives of Pediatrics and Adolescent Medicine, British Medical Journal, Journal of the American Medical Association, Journal of Pediatrics, The Lancet, New England Journal of Medicine, Pediatric Infectious Diseases Journal, and Pediatrics. Gurpreet K. Rana, BSc, MLIS, Taubman Medical Library, University of Michigan, contributed to the review and selection of this month’s abstracts. —John G. Frohna, MD, MPH
Early television exposure and subsequent attentional problems in children
potential mechanisms underlying this relationship, and the effects of various types of programming content.
Christakis DA, Zimmerman FJ, DiGiuseppe DL, McCarty CA. Pediatrics 2004;113:708-13
Neuroscience confirms the power of environmental experiences in shaping the developing brain. Repeated exposure to any stimulus in a child’s environment may forcibly impact mental and emotional growth, either by activity-induced growth (‘‘wiring by firing’’) or by neural pruning of neglected potential (‘‘use it or lose it.’’).1 These shaping processes, affecting structure and function, involve both cellular development and neurotransmitter regulation. Although little developmental research has specifically targeted attention systems, which include interlocking feed-forward and feedback loops and associated catecholamine neurotransmitters in prefrontal and subcortical areas,2 there is every reason to believe that their gradual maturation implies a degree of malleability. Interesting unanswered questions are to what degree catecholamine mechanisms, implicated in stimulusseeking and addictive behaviors as well as in attention disorders, can be ‘‘set’’ by childhood experiences such as exposure to arousing types of electronic media, or whether insistent noise of television in the home may interfere with the development of ‘‘inner speech,’’ by which a child learns to think through problems and plans and restrain impulsive responding.
Context Cross-sectional research has suggested that television viewing may be associated with decreased attention spans in children. However, longitudinal data of early television exposure and subsequent attentional problems have been lacking. Objective To test the hypothesis that early television exposure (at ages 1 and 3) is associated with attentional problems at age 7. Design Longitudinal population survey, using data from the National Longitudinal Survey of Youth. Participants More than 11,000 children of a nationally representative sample. Main outcome measure The hyperactivity subscale of the Behavioral Problems Index determined on all participants at age 7. Children who were $1.2 SD above the mean were classified as having attentional problems. The main predictor was hours of television watched daily at ages 1 and 3 years.
Conclusions Early television exposure is associated with attentional problems at age 7. Efforts to limit television viewing in early childhood may be warranted, and additional research is needed.
Research has clearly demonstrated a genetic component in attention deficit-hyperactivity disorder (ADHD)3; current treatments emphasize well-advertised drugs that purport to normalize catecholamine (dopamine, norepinephrine) function.4 Often dramatic improvement is seen on a drug regimen, so writing a prescription is an obvious choice for overscheduled physicians. Yet the contribution of environmental factors to attention disorder has barely been touched by systematic research. This study’s indication that an omnipresent environmental agent is associated with ADHD suggests that early preventive efforts should also be emphasized.
Comment The provocative findings by Christakis et al are long overdue. The researchers’ systematic approach, wide variety of variables, and group size all lend credibility and create a new imperative for follow-up investigations quantifying more specifically the diagnosis of ‘‘attentional problem,’’
A recent survey found that 43% of children aged 2 and younger watch television everyday, and 26% have a television in their bedrooms. The study also showed 68% of children under the age of 2 spend slightly more than 2 hours per day using screen media.5
Results Data were available for 1278 children at age 1, and 1345 children at age 3; 10% of children had attentional problems at age 7. In a logistic regression model, hours of television viewed per day at both ages 1 and 3 was associated with attentional problems at age 7 (1.09 [1.03–1.15] and 1.09 [1.02–1.16]), respectively.
Clinical Research Abstracts for Pediatricians
679
Now that we have an ‘‘epidemic’’ of ADHD, it is indeed time to ask the research questions so ably initiated by Christakis et al and to consider pediatricians’ responsibility in educating parents about placing limits on ‘‘screen time.’’
Jane M. Healy, PhD Vail, CO 81657
REFERENCES 1. LeDoux J. Synaptic self. New York: Viking/Penguin; 2002. 2. Solitano MV, Arnsten AFT, Castellanos FX, eds. Stimulant drugs and ADHD: basic and clinical neuroscience. Oxford (UK): Oxford University Press; 2001. 3. Barkley RA. Attention-deficit hyperactivity disorder: a handbook for diagnosis and treatment. 2nd ed. New York (NY): Guilford; 1998. 4. ADHD and executive functions: impact of age, gender, and new treatment options. Seminar sponsored by Eli Lilly and Co. Presented at the 111th Annual Convention of the American Psychological Association, August 9, 2003, Toronto, Ontario, Canada. 5. Rideout VJ, Vandewater EA, Wartella EA. Zero to six: electronic media in the lives of infants, toddlers, and preschoolers. Publication no. 3378. Menlo Park (CA): Kaiser Family Foundation; 2003.
Preventing childhood obesity by reducing consumption of carbonated drinks: Cluster randomised controlled trial
and its effect on obesity. Although the results of this intervention showed modest changes in soda consumption, there did appear to be a notable reduction in the number of obese and overweight children. There were several limitations to this study. Although the classes within a school were randomized, there was a risk of cross-contamination between classes. There may be some response bias, as only a small percentage of diaries were completed (36%). The authors addressed this, noting that the rates of obesity were the same in responders and nonresponders. They also state the baseline consumption of soda was the same in the two groups. The fact the diaries were only collected for a three-day period further limits the results, as this may not be a true indicator of the child’s average soda consumption. Despite these limitations, this study provides hope that interventions targeting single variables may be successful in limiting obesity, and it draws our attention to the significant contribution soda consumption has on childhood obesity. Parents and schools may be overwhelmed with messages regarding diet, nutrition, and exercise. This intervention gives parents and children a specific goal, to decrease soda consumption, with the benefit of weight reduction. The fact that this intervention requires little teacher or school training and can be provided with relative ease makes it even more appealing.
James J, Thomas P, Cavan D, Kerr D. BMJ 2004;328:1237-42 Context Obesity in children seems to be related to the consumption of sugar-sweetened carbonated drinks. Objective To determine if a school-based educational program aimed at reducing consumption of carbonated drinks can prevent excessive weight gain in children. Design Cluster randomized controlled trial. Setting
Six primary schools in southwest England.
Participants
644 children aged 7-11 years.
Interventions Focused educational program on nutrition throughout one school year. Main outcome measures Drink consumption and number of overweight and obese children. Results Consumption of carbonated drinks over 3 days decreased by 0.6 glasses (average glass size 250 ml) in the intervention group but increased by 0.2 glasses in the control group (mean difference 0.7; 95% CI, 0.1-1.3). At 12 months the percentage of overweight and obese children increased in the control group by 7.5% compared with a decrease in the intervention group of 0.2% (mean difference 7.7%, 2.2-13.1). Conclusions A targeted, school based education program produced a modest reduction in the number of carbonated drinks consumed, which was associated with a reduction in the number of overweight and obese children. Comment While multivariable intervention programs have shown minimal effects on rates of obesity,1,2 this study focused on a single variable, the consumption of carbonated beverages,
680
Clinical Research Abstracts for Pediatricians
Heather Van Mater, MD Department of Pediatrics, University of Michigan Ann Arbor, MI 48109
REFERENCES 1. Atkinson RL, Nitzke SA. School based programmes on obesity. BMJ 2001;323:1018-9. 2. Sahota P, Rudolf MCJ, Dixey R, Hill AJ, Barth JH, Cade J. Evaluation of implementation and effect of primary school based intervention to reduce risk factors of obesity. BMJ 2001;323:1027-9.
A comparison of high-dose and standard-dose epinephrine in children with cardiac arrest Perondi MB, Reis AG, Paiva EF, Nadkarni VM, Berg RA. N Engl J Med 2004;350:1722-30 Context When efforts to resuscitate a child after cardiac arrest are unsuccessful despite the administration of an initial dose of epinephrine, American Heart Association guidelines recommend that the next dose of epinephrine (ie, the rescue dose) should be the same (standard) dose or a higher dose. Objectives To evaluate whether rescue therapy with highdose epinephrine compared with continued use of the standard dose, would improve the rate of survival at 24 hours for children who had an in-hospital cardiac arrest. Design Prospective, randomized, double-blind trial. Setting Children’s Institute of the University of S~ ao Paulo School of Medicine, a tertiary-care children’s hospital that admits more than 6000 patients each year.
The Journal of Pediatrics November 2004