Anhedonia, i.e. the inability to feel pleasure. It's like trying to fill a bucket with water that has a hole in the bottom, letting the water out at the same speed it goes in. Nothing you can do about it. I think this might be where the recklessness comes from; desperation to get any kind of sensation from something. You need to go to extreme lengths to get the proverbial dial to move a millimetre. So you take risks and reach for danger and generally inappropriate behaviour.