It seems that a Pokémon afflicted with both the confusion status and curse (used by a ghost-type pkm) will not take damage damage from the curse tick if it took damage from the confusion that turn.

Unsure if this is specific to either the Confusion or Curse effect or if this could be replicated with other forms of indirect damage such as entry hazard, weather hazard, status effect, etc.

 

Example: Gastly uses curse on Quagsire. Quagsire takes curse damage that turn. Next turn, Gastly uses confuse ray on Quagsire. Quagsire hits itself in confusion, takes damage from it but the curse tick doesn't apply.

 

EDIT: I had done a search before posting and it didn't return anything, but when I browsed manually through the forums I found this topic

I'll leave this thread up since the other one is locked, the devs seemingly thinking the issue was resolved. However it would seem that it really isn't. Again, this issue will need to be tested with various forms of indirect damage.

Bump with new information: sleep status stops the curse ticks. Ticks resume upon removal of the status.