• Time from start of double-blind phase to relapse, using N-CBRF and CGI assessments.
  

• Comparison of ratings for risperidone and placebo on N-CBRF, CGI, and VAS-MS throughout study. Ratings on C-GAS once during each study phase. Comparison of safety profiles of risperidone and placebo (for example, adverse events, clinical and lab tests).
  

This is a randomized, double-blind study to compare an oral formulation of risperidone with placebo when taken daily over 24 weeks by children and adolescents with conduct and other disruptive behavior disorders. Patients who do not respond to treatment after an initial 6-week open-label phase, or do not show continued response after 12 weeks, must leave the trial and will not enter into the 24-week double-blind phase. The principal measure of efficacy is the time to symptom relapse. Relapse is assessed by changes in following measures: the Conduct Problem subscale of the Nisonger Child Behavior Rating Form (N-CBRF), a measure of symptoms of conduct and other disruptive behavior disorders and Clinical Global Impression-Severity of Illness (CGI-Severity), and a measure of overall severity of illness. Efficacy assessment also includes Clinical Global Impression-Change (CGI-C), an assessment of imporvment, and Visual Analogue Scale for the most troublesome symptom (VAS-MS), which is a scale ranging from not troublesome to extremely troublesome, and Children's Global Assessment Scale (C-GAS), which is an assessment of overall functioning. Safety evaluations include incidence of adverse events, physical examinations, laboratory tests (biochemistry, hematology, and urinalysis), and electrocardiograms (ECGs). The study hypothesis is that daily treatment with an oral formulation of risperidone, compared with placebo, will result in a clinically significant difference in time to relapse, and is well tolereated by children and adolescents with conduct and other disruptive behavior disorders.

Oral risperidone solution (1milligram[mg]/milliter [ml]), daily for 36 weeks. Patients weighing at least 50 kilograms start at 0.5 ml/day and may increase up to.1.5 ml/day. Patients under 50kg start at 0.25ml/day and may increase to 0.75ml/day (maximum).