En mulig forklaring på behandlingssvigtet i dette forsøg er, at carbamazepin inducerer clearance af risperidon og 9- hydroxyrisperidon, hvilket medfører subterapeutiske niveauer af risperidon og 9- hydroxyrisperidon.
A possible explanation for the failure of this study was induction of risperidone and 9-hydroxy-risperidone clearance by carbamazepine, leading to subtherapeutic levels of risperidone and 9-hydroxy-risperidone.