Despite four decades of research, the physics responsible for the negative-bias temperature instability (NBTI) in p-channel metal-oxide-silicon field-effect transistors is still unresolved. The current NBTI debate focuses on the dominance of either a hole trapping/detrapping mechanism or a hydrogen depassivation mechanism. In this study, we present NBTI-induced changes in the peak transconductance which indicate the presence of a third mechanism involving electron trapping/detrapping. The presence of this electron trapping/detrapping component adds further complexity to the very complicated NBTI phenomenon.