ARTICLES
Stimulant Treatment Over Five Years: Adherence, Effectiveness, and Adverse Effects

https://doi.org/10.1097/00004583-200405000-00009Get rights and content

ABSTRACT

Objective

To evaluate the impact of adherence and medication status on effectiveness and adverse effects of stimulant use in children with attention-deficit/hyperactivity disorder (ADHD) over 5 years.

Method

Seventy-nine of 91 participants in a 12-month randomized controlled trial of methylphenidate and parent groups enrolled in a follow-up study. Adherence to stimulants, treatment response, and adverse effects were evaluated annually for 5 years. Changes in teacher-reported symptoms and parent-reported adverse effects were compared at 2, 3, 4, and 5 years for 3 groups: adherents, nonadherents on medication, or nonadherents off medication. Controlling for age, gender, and baseline severity, adherence status and medication status were evaluated as correlates of teacher-reported ADHD symptom scores at each year using multiple regression analyses.

Results

At 2 years, adherents (n = 41) showed greater improvement in teacher-reported symptoms than those off medication (n = 16) and equivalent response to nonadherents on stimulants (n = 16) (p = .02). At 5 years, adherents (n = 16) showed greater improvement in teacher-reported symptoms than nonadherents on stimulants (n = 15) and those off medication (n = 14) (p = .04). At year 2 medication status (β = 4.67 [0.40–8.95, p = .033]) and at year 5 adherence status (β = 7.23 [3.01–11.44, p = .001]) correlated with higher teacher-reported symptom scores. Clinically significant adverse effects were present for 5 years, most commonly loss of appetite.

Conclusions

Psychostimulants improve ADHD symptoms for up to 5 years, but adverse effects persist.

Section snippets

Subjects

Participants were 79 children who enrolled in a follow-up study after completing a 12-month randomized controlled trial of combined MPH and parent-treatment programs, the first 4 months of which are described by Schachar et al. (1997). The original trial, begun in 1993, included children with a confirmed diagnosis of ADHD drawn from 302 referrals to an assessment and treatment program for ADHD at the Hospital for Sick Children, Toronto. Referrals were approximately one third from physicians,

RESULTS

Of the 91 original participants, 79 (87%) enrolled in the follow-up study, all of whom remained in the study at 2 years. There were 78 (86%) children at 3 years, 73 (80%) at 4 years, and 69 (76%) at 5 years. In general, a similar pattern of baseline measurement was seen among participants at each annual evaluation. The participants who remained in the study did not differ significantly from those who dropped out of the study in terms of sex, age, baseline ADHD scores as measured by the parent

DISCUSSION

The current report documents that use of stimulant medications improves symptoms of ADHD, as reported by teachers, after 2 years and beyond. Children who were using stimulant medication at consecutive annual evaluations showed ongoing benefit. Adherents tended to be children who had more severe symptoms at baseline, and, while still symptomatic, they showed greater treatment response at 5 years than nonadherents. Among those who were nonadherents at 5 years, children on stimulants had fewer

REFERENCES (33)

  • PA Ahmann et al.

    Placebo-controlled evaluation of Ritalin side effects

    Pediatrics

    (1993)
  • American Psychiatric Association

    Diagnostic and Statistical Manual of Mental Disorders, 3rd edition-revised (DSM-III-R)

    (1987)
  • RA Barkley et al.

    The adolescent outcome of hyperactive children diagnosed by research criteria, I: an 8-year prospective follow-up study

    J Am Acad Child Adolesc Psychiatry

    (1990)
  • RA Barkley et al.

    Side effects of methylphenidate in children with attention deficit hyperactivity disorder: a systemic, placebo-controlled evaluation

    Pediatrics

    (1990)
  • J Biederman et al.

    A prospective 4-year follow-up study of attention-deficit hyperactivity and related disorders

    Arch Gen Psychiatry

    (1996)
  • J Biederman et al.

    Pharmacotherapy of attention-deficit/hyperactivity disorder reduces risk for substance use disorder (electronic abstract e20)

    Pediatrics

    (1999)
  • MH Boyle et al.

    Ontario Child Health Study, I: methodology

    Arch Gen Psychiatry

    (1987)
  • MH Boyle et al.

    Evaluation of the revised Ontario Child Health Study scales

    J Child Psychol Psychiatry Allied Disciplines

    (1993)
  • RT Brown et al.

    Methylphenidate and cognitive therapy with ADD children: a methodological reconsideration

    J Abnorm Child Psychol

    (1986)
  • RT Brown et al.

    Compliance with pharmacological and cognitive treatments for attention deficit disorder

    J Am Acad Child Adolesc Psychiatry

    (1987)
  • P Corkum et al.

    Parental knowledge of attention-deficit hyperactivity disorder and opinions of treatment options: impact on enrollment and adherence to a 12-month treatment trial

    Can J Psychiatry

    (1999)
  • P Corkum et al.

    Sleep disturbances in children with attention-deficit/hyperactivity disorder

    J Am Acad Child Adolesc Psychiatry

    (1998)
  • P Firestone

    Factors associated with children's adherence to stimulant medication

    Am J Orthopsychiatry

    (1982)
  • C Gillberg et al.

    Long-term stimulant treatment of children with attention-deficit hyperactivity disorder symptoms. A randomized, double-blind, placebo-controlled trial

    Arch Gen Psychiatry

    (1997)
  • R Gittelman et al.

    Hyperactive boys almost grown up, I: psychiatric status

    Arch Gen Psychiatry

    (1985)
  • S Harter

    The Perceived Competence Scale for Children

    Child Dev

    (1982)

    • Cited by (0)

    This research was funded by the National Health Research Development Program of Canada and the Department of Psychiatry, The Hospital for Sick Children, Toronto. The authors thank S. Bockus, S. Chen, P. Corkum, C. Cunningham, P. Rimer, R. Tannock, and D. Thirulchelvam for their contribution to this research. This paper was prepared with the assistance of Editorial Services, The Hospital for Sick Children, Toronto.

    Financial Disclosure: Dr. Ickowicz has participated in industry-sponsored research grants and has been on the advisory board and/or has acted as a consultant for Eli Lilly Canada Inc., Janssen-Ortho Inc., and Purdue Pharma. Dr. Schachar is supported by Canadian Institutes for Health Research and has acted as a consultant for Eli Lilly Canada Inc. and Purdue Pharma.

    View full text
    Copyright © 2004 The American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.