An investigation of prepulse inhibition in pediatric bipolar disorder

Objectives: Deficits in prepulse inhibition (PPI), a measure of sensorimotor gating, have been noted in psychopathologies including schizophrenia and adult bipolar disorder (BPD). Sensorimotor gating deficits may contribute to the emotional and behavioral dysregulation characteristic of pediatric BPD. The current study investigated possible PPI deficits in children with BPD. Methods: Sixteen children with BPD (medicated, euthymic and non-psychotic) were compared with 13 control subjects on the magnitude of startle habituation, startle-alone response, and inhibition of startle following a 60 or 120-ms prepulse. Results: Both groups displayed startle inhibition by a prepulse, with no significant between-group differences on the magnitude of inhibition after the 60- or 120-ms prepulse. In addition, there were no between-group differences on habituation or baseline startle response. PPI level was not significantly correlated with mood symptoms and did not differ based on comorbid attention deficit hyperactivity disorder. Conclusions: A lack of PPI deficits in our pediatric bipolar sample contrasts with previous results in adult bipolar and schizophrenic samples. These negative results may reflect the fact that our sample was medicated and was neither acutely manic nor psychotic. Deficits in sensorimotor gating may not be implicated in the emotional and behavioral dysregulation in pediatric BPD.