Methylphenidate and comorbid anxiety disorder in children with both chronic multiple tic disorder and ADHD

To determine if comorbid anxiety disorder is associated with differential response to immediate release methylphenidate (MPH-IR) in children with both ADHD and chronic multiple tic disorder (CMTD).

Children with (n = 17) and without (n = 37) diagnosed anxiety disorder (ANX) were evaluated in an 8-week, placebo-controlled trial with rating scales and laboratory measures.

The +ANX group obtained more severe parent, teacher, and child ratings of anxiety and more severe parent ratings of depression, tics, oppositional defiant disorder (ODD), and peer aggression than the -ANX group. Treatment with short-term MPH-IR was associated with improvement in ADHD, ODD, and peer aggression in the +ANX group. When controlling for ODD severity, there were no apparent group differences in therapeutic response to MPH-IR in children ±ANX. There was little evidence that MPH-IR contributed to improvement in anxiety or depression symptoms in the +ANX group. There was some indication that children with comorbid anxiety may differentially experience greater increase in systolic blood pressure (0.5 mg/kg of MPH-IR > placebo).

Findings suggest that the co-occurrence of diagnosed CMTD+ADHD+ANX represents a particularly troublesome clinical phenotype, at least in the home setting. Comorbid anxiety disorder was not associated with a less favorable response to MPH-IR in children with ADHD+CMTD, but replication with larger samples is warranted before firm conclusions can be drawn about potential group differences.