Mental illness
Mental illnesses are status effects that are very hard to get rid of and can often effect you for odd reasons, either because you read/wore the wrong thing or because you have a particular mutation. Things that cause mental illnesses commonly are Buckethead's bucket, which will give you a random mental illness when worn, but not if you already have one. Aside from that, Hideous Freaks and Abominations reclone with one, and sometimes two. Players with the vampire mutation get mental illnesses when they get hungry enough. While mental illnesses are inconvenient, they rarely come without at least one upside, making them somewhat a mental form of rad mutations.
(incomplete)List Of Mental Illnesses
Christianity
Cause
Reading a bible
Effect
You may go to heaven rather then limbo when you die. You will also gain a descriptive line about looking like an asshole in an indeterminate way.
Republicanism
Cause
Wearing a bucket on your head (at least thats how I got it)
Effect
-1 to brains
Megalomania
Cause
Unknown
Effect
No documented effect
Claustrophobia
Cause
unknown
Effect
Constant stress gain while indoors. Status screen will say "you feel like the walls are closing in on you"
Nymphomania
Cause
The Goo Fountain in Hellfire
Effect
Randomly doses you with the Rapinex drug, causing you to take off your clothes and prematurely dissipating your endorphins. The benefit to this is it means you can whore more often, if that's your thing. A downside is that you end up getting stressed if you go too long without sexual contact.
How to deal with the screaming purple bears in your head
Mental illness is hard to get rid off, requiring either an experienced medic with costly equipment, an empath or a hot bullet to the brain. If you get a mental illness you can always whine on chatnet for someone to help you, you will be completely ignored though.