Dementia I is hitting for a large amount initially, around 100 less than max of the range specified in the spell tooltip. It then his for an additional 3 ticks each tick ranging from approx. 130 to 180. Tooltip states this is suppposed to be a dot.
Additionally, Dementia II hits for the full amount stated in the description instead of acting as a dot over 8sec It is hitting within the specified damage range indicated in the spell description.
As it is now it is not unusual to do more damage iwth Dementia 1 vs Dementia II. Of course, Dementia I is hitting too hard currently.