The stat decrease from Abhorrent Spectres lasts until it naturally recovers, which happens at about 1 level per minute for drained stats.

In practice, that means the effect is temporary rather than a fixed-duration debuff. If you want it removed immediately, a restore potion or similar stat- restoring effect will clear it faster.

Quick note

  • The source result I found describes the recovery rate for spectre-drained stats as 1 level per minute.
  • I didn’t find a separate, specific timer for Abhorrent Spectres distinct from the normal spectre drain in the available result.