|Description||Increased serotonin production causes hosts to laze around all day without achieving anything. Reduces happiness|
|Previous symptom||Festive Tendrils|
Sloth is a tier 3 symptom exclusive to the Christmas-themed Neurax Worm scenario Santa's Little Helper. It makes hosts lazy and unproductive, making them less happy overall. Evolving this alongside the symptoms Gluttony and Intoxication unlocks the On The Naughty List achievement.