Like many characters in the series, Spike has battled depression at times; however, this was less a tendency towards self-pity or a psychological character trait than a reaction to new limitations. After being 'chipped' by the Initiative, Spike's inability to act out violence put him at odds with his desire to resist control and authority, and he became sullen when the pain inflicted by the chip was simply too powerful to resist. Upon realizing that he could still battle (and kill) demons and other supernatural creatures, his confidence immediately returned. Later, Spike's greatest internal conflict arose due to simultaneously wanting to kill the Slayer (Buffy) due to her authority and position as the "one thing" that vampires fear, until discovering that he was sexually and romantically attracted to Buffy as a person. Recognizing that his affection for her gave her power over him caused him a great deal of self-doubt; seeing no other means to reconcile the dissonance, he chose instead to 'rebel' against his vampire nature itself, and eventually seek to be re-ensouled and purify his passions.