Myoclonus during prolonged treatment with sertraline in an adolescent patient

A 15-year-old female adolescent with depression developed myoclonus after u ninterrupted treatment with sertraline over 6 years. She was also receiving methylphenidate, Withdrawal of sertraline and continuation of methylphenid ate did not result in any improvement. Treatment with valproic acid resulte d in improvement of the movement disorder. This report suggests that myoclo nus may be a side effect of sertraline in some adolescents. Further, we hyp othesized that extended treatment over several years, young age, and a comp romised central nervous system due to underlying disorders may be risk fact ors for the development of this side effect.