As an artist the I experience the hyper focus as a trance and loss of time. I can work for hours at a time only stopping when I realise that I can’t see any more because the sun went down an hour ago. I have inattentive type so there are times that I don’t even hear when people are talking to me. I don’t suffer from a drop in productivity but I will start to hurt myself more than normal . For me the downside is that I have trouble relating with other humans after working 16 hours straight. Its almost like I forget how to communicate or even comprehend what is going on around me. I am more like a bear than a person at that stage its best not to approach me and let me go hibernate. I think this is a result of dopamine levels being completely depleted. There have been times that I don’t remember stopping, someone had to come in and take me away. I just wake up the next day with vague recollections of being put in pajamas and put to bed. luckily I don’t have this problem as much when I am on meds.