December 4, 2007 – Methylphenidate (Ritalin®, Concerta®, Metadate®) effective and safe for treating children with Attention Deficit Hyperactivity Disorder (ADHD)? The issue has resurfaced periodically since the 1990s.
The debate has picked up in recent months, following the publication of four American studies from the Multimodal Treatment Study of Children with ADHD1 (MTA). During this second phase of the study, the same researchers wanted to know what happened to the children after two years of treatment.
According to the results, published recently in the journal of theAmerican Academy of Child and Adolescent Psychiatry, ADHD medications may not be as effective as they thought in the long term2.4. They could also cause stunted growth in children5.
ADHD drugs would no longer provide measurable benefits to children after two years of treatment, that is, those who still have significant symptoms, conclude the researchers who participated in the second phase of the study.
For half of the subjects in the cohort, however, the drugs were shown to be effective during the first or second year. The improvements observed were also maintained even after a year without medication.
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Ritalin: a drug with paradoxical effects Patented for the first time in 1954 under the name Ritalin®, methylphenidate is a psychotropic drug that acts like cocaine: it stimulates the central nervous system by inhibiting dopamine reuptake, which increases the concentration of this neurotransmitter in the brain. Although it is a stimulant, it has paradoxical effects in hyperactive people: it lowers restlessness and increases attention span. Methylphenidate has been used since 1960 to treat children with ADHD, but the drug’s use has grown significantly since the 1990s. The American authorities then launched the Multimodal Treatment Study of Children with ADHD to assess the efficacy and safety of the drug in a cohort of nearly 600 children treated for two years for ADHD. In 1999, researchers concluded that methylphenidate was effective and safe over a two-year period. |
Divided opinions
According to psychology professor William Pelham of the University of Buffalo, a member of the team that conducted the first phase of the MTA study, the effectiveness of methylphenidate was initially overestimated. “There is no indication that the medication is more effective than any other intervention,” he said. He would have liked the study protocol to place more emphasis on non-drug psychotherapeutic interventions.
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Reinforcement of psychotherapy? |
For her part, psychiatrist Lily Hechtman, head of the ADHD clinic at the Montreal Children’s Hospital and member of the team of researchers who conducted the MTA study, interprets the results of the second phase of the study differently. . “The studies do not question the effectiveness of the medication, but they highlight the fact that the starting dosage is too often poorly determined and that the monitoring of children on medication is unfortunately inadequate. “
The results collected for the second part of the study concern children who were treated in the community and who no longer benefited from the close follow-up to which they were entitled during the first phase of the study, she explains. The dosage of the drug was then carefully established at the outset for each child, and the treatment was adjusted, if necessary, once a month. In the community, moreover, follow-up comes down most of the time to one or two medical visits per year, and it is often unclear whether the medication is adequately prescribed and whether the child is adhering to it correctly and diligently, specifies the psychiatrist.
Same story with the Dr Philippe Lageix, psychiatrist attached to the Douglas Mental Health University Institute and the Rivière-des-Prairies Hospital, who has been dealing with ADHD subjects for nearly 20 years. “You need a minimum of two years of continuous medication at the start, with dose adjustment every three months,” he notes. After that, it depends on the progress of the child, he continues. “Symptoms vary from one individual to another and it is necessary to constantly reassess the functional capacities of the patient and his degree of adaptation to what society expects of him. “
According to the two psychiatrists, children who are still on medication after three years, and who derive little benefit from treatment, are heavier cases or have benefited from inadequate follow-up. This explains, according to them, that we observe more delinquent behavior in children taking medication for more than three years than in those who are no longer on medication.4.
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As much for boys as for girls |
Stunted growth
Children on medication for three years are believed to be stunted in the order of 2 cm in size and 2.7 kg in body weight compared to children without medication, other study results show.5. It is known that methylphenidate can have an appetite suppressant effect.
Some researchers believe that periodic medication holidays should be planned in order to allow the child to resume a normal rate of growth. Others believe that such medication discontinuation should be evaluated by the child by his or her attending psychiatrist, the only one who can determine whether the medication discharge is likely to result in a resurgence of ADHD symptoms. .
In light of the results of this second part of the MTA study, it is to be expected that the debate surrounding ADHD treatment will continue to cast much ink in the years to come.
Pierre Lefrançois – PasseportSanté.net
According to BBC News.
1. This research program is funded by the National Institute of Mental Health, the United States’ authority for the evaluation of drugs and therapies in use for the treatment of mental ailments and behavioral disorders.
2. Jensen PS, Arnold LE, et al. 3-year follow-up of the NIMH MTA study. J Am Acad Child Adolesc Psychiatry. 2007 Aug; 46 (8): 989-1002.
3. Swanson JM, Hinshaw SP, et al. Secondary evaluations of MTA 36-month outcomes: propensity score and growth mixture model analyzes. J Am Acad Child Adolesc Psychiatry. 2007 Aug; 46 (8): 1003-14.
4. Molina BS, Flory K, et al. Delinquent behavior and emerging substance use in the MTA at 36 months: prevalence, course, and treatment effects. J Am Acad Child Adolesc Psychiatry. 2007 Aug; 46 (8): 1028-40.
5. Swanson JM, Elliott GR, et al. Effects of stimulant medication on growth rates across 3 years in the MTA follow-up. J Am Acad Child Adolesc Psychiatry. 2007 Aug; 46 (8): 1015-27.
6. Hechtman L, Abikoff H, et al. Children with ADHD treated with long-term methylphenidate and multimodal psychosocial treatment: impact on parental practices. J Am Acad Child Adolesc Psychiatry. 2004 Jul; 43 (7): 830-8.
