Plague Inc. Wiki

Insanity is a symptom in the Standard Plagues & Neurax Worm.

Standard Plagues

This symptom causes severe emotional and behavioral abnormalities in infected patients, making it significantly harder to cure.

Neurax Worm

In the Neurax Worm DLC, unlike normal insanity, this variation of the symptom is slightly lethal, possibly because of dangerous things people may do. Countries affected by insanity will open insane asylums, which will decrease public order.

Cure Mode (Prion)

In Cure Mode, this symptom is on the Prion disease type, which means that infected won't work on the cure as effectively. The Neural Enhancers operation can counter the effects of Insanity and cause infected to work on the cure much more.


  • If evolved in conjunction with Hyper Sensitivity in the Artificial Organs scenario during organ production and distribution, the infected will begin to tear out their artificial organs, causing a jump in the death rate and possibly interrupting the process of unlocking I never asked for this.
  • Interestingly, when combined with Paranoia, it can cause nuclear explosions, which are said to be sabotaged power plants. Likely, however, it is possibly due to a breakout of nuclear war. Such an outcome is implied by the achievements Chinese Nuclear Retaliation and Russian Nuclear Retaliation, both of which involve evolving Insanity as part of obtaining the achievement.
  • This is the only tier 4 symptom that does not increase lethality at all. As such, its main usage is to reduce cure progress.


InsanityCard.png Insanity Symptom Card from Plague Inc.: The Board Game