Gabapentin and methylphenidate treatment of a preadolescent with attention deficit hyperactivity disorder and bipolar disorder.

Gabapentin is an anticonvulsant drug released in the United States in 1993 for use as adjunctive therapy in refractory partial epilepsy. The mechanism of action of gabapentin is unknown, but the drug has very favorable pharmacokinetics and a good safety profile, which allows its use in high-risk patients. Several reports have described the successful use of gabapentin for bipolar disorders in adults, but there are no controlled studies in the use of gabapentin in children and adolescents. We describe a 12-year-old boy with a history of attention deficient hyperactivity disorder (ADHD), reading disorder, mixed receptive and expressive language disorder, encopresis, and bipolar disorder II who was treated with gabapentin 200 mg/day added to methylphenidate 30 mg/day. Within 3 weeks the improvement and stabilization of mood symptoms was remarkable, as noted by mother, teacher, and clinician, and remained so for 6 months of follow-up. Comorbid bipolar disorder and ADHD is a hotly debated topic in the child and adolescent psychiatric literature, with rates of comorbid ADHD and bipolar disorder ranging from 22% to 90%. Controlled studies are needed to evaluate the possible antimanic mood stabilizing and/or antidepressant properties or gabapentin in youths.