Narcolepsy, cataplexy and emotions form an intriguing triad that fascinates sleep researchers. A novel aspect of narcoleptic patients' behaviours now appears depending on the emotional valence of the context: how can we explain the fact that narcoleptic patients may experience pleasant-triggered (e.g. laughing) cataplexy as well as unpleasant-related drawback performance (Tucci, V., Stegagno, L, Vandi, S., Ferrillo, F., Palomba, D., Vignatelli, L, Ferini-Strambi, L, Montagna, P., Plazzi, G., Emotional information processing in patients with narcolepsy: a psychophysiologic investigation, Sleep 26 (2003) 558-564; Khatami, R., Birkmann, S., Bassetti, C.L, Amygdala dysfunction in narcolepsycataplexy, J. Sleep Res. 16 (2007) 226-229)? With this in mind we postulate that narcolepsy with cataplexy is a complex sleep disorder that, among others, affects the modulation of emotions at different levels: structural, cellular and molecular. (C) 2008 Elsevier Ireland Ltd. All rights reserved.