Conversely, if you ever find yourself in a situation (in solo content) that you need to use Drain, you're being a bad player.
As it was, it was a rubbish skill that either needed changing, or removing. Even a triplecast Drain yielded about 20% of your health back and you still had to cast it over 5-6 seconds and by that point, your healer should have you covered or in the case of solo content, the server healclick.