This multicenter , double-blind , randomized , placebo-controlled , relapse-prevention trial enrolled patients ( 6-17 years ) who met the current Diagnostic and Statistical Manual of Mental Disorders , Fourth Edition , Text Revision ( DMS-IV-TR ) criteria for autistic disorder and who also had serious behavioral problems ( ie , tantrums , aggression , self-injurious behavior , or a combination of these behavioral problems ) between March 2011 and June 2012 .