agitation apparently. often people want to take the SSRI's 'this will cure me!' so they take 'em and find that they get all jittery and restless. moving moving moving. not a 'gee i must be getting better i'm starting to want to do things now' but i leg jiggling incessant moving kind of an anxiety response.

moving moving jumping off of a building. restless thoughts round and round. some people say that while they might have contemplated suicide before the quality of the thoughts on SSRI'S is different. more incessant. faster. round and round.

of course the drug companies have said that SSRI's might result in an increase in suicide because it gives people energy (a part of getting better) that they then have to use and they decide to act on suicidal thoughts they already had.

sceptics / critics say that the nature and quality of the agitation is different from 'getting better' and the nature and quality of the suicidal thinking changes too.

so... i think it is to do with the physiological effects of the medication. most people start to feel a little agitated when their body adjusts to an SSRI. some people just have a more intense reaction than others.