Preliminary Findings of Guanfacine in Comorbid ADHD and Habit Disorder-Open Trial

Kim, Youngshin; Scahill, Lawrence; Leckman, James

Abstract

OBJECTIVE
Attention Deficit/Hyperactivity Disorder(ADHD) and tic disorders are relatively common childhood onset neuropsychiatric disorders, and these two disorders frequently cooccur in some individual. Although the efficacy of psychostimulants is well established in ADHD, as many as 25% of children fail to respond to psychostimulant treatment due either to a lack of efficacy or to intolerable side effects including exacerbations of tics. Guanfacine, a selective alpha2A-adrenergic agonist, was recently introduced for the treatment of children with ADHD. This study is to evaluate the efficacy and safety of guanfacine in children with ADHD and comorbid habit disorders and to identify subgroups of children who may have a more favorable response to guanfacine.
METHODS
Twenty five children who were 6 to 16 years old were enrolled in an open trial of guanfacine for two months. Primary outcome measures were DuPaul Parent and Teacher Rating Scales, Conners Parent and Teacher Rating Scales and Yale Global Tic Severity Scale. Paired t-test and multiple logistic regression were performed to evaluate symptom improvement and to examine predictor variables for positive drug response.
RESULTS
Severity of ADHD symptoms and tics after guanfacine administration was significantly reduced at each follow-up point in the ratings completed by both parents and teachers and in clinical evaluation, compared to their pre-medication status. Children with moderate ADHD symptoms responded more favorably to guanfacine than children with mild or severe symptoms.
CONCLUSION
These findings suggest that guanfacine may be a safe and an effective medication for ADHD children who cannot benefit from psychostimulants, but more definitive research strategies are needed for future investigation.