Bloodthistle Withdrawal is a debuff which reduces Spirit by 5 for 20 minutes, received when the buff from eating or runs out. The debuff is removed if more bloothistle is consumed (either kind), renewing the buff and delaying the withdrawal. This game mechanism simulates a symptom of drug addiction.
Since only Blood elves can use either Bloodthistle item, only Blood elves can experience Bloodthistle Withdrawal.
has additional lore and more options for removing the debuff.