Just to follow up from [this question](https://buddhism.stackexchange.com/q/5981/157) - is it possible for an individual to meditate too much? Is there a point when it becomes counterproductive and if so what would the signs be that someone should slacken off their meditation routine?

Just to be clear - I am talking about a meditation routine outside of a retreat setting. The question is about someone's daily meditation routine rather than during a retreat when the conditions and level of support one would receive would be very different.