…and the japanese are out to cure them.https://www.helprx.info/blog/schizophrenia/schizophrenia-research-cave-fish
>The blind cave fish Mexican tetra exhibits similar characteristics to humans with schizophrenia. The species as a whole is solitary due to a lack of natural predators. They have no need to join protective schools and are instead able to independently navigate underwater using variations in water pressure and vibrations. >Despite their safety in the dark recesses, they remain anxious and restless. The fish repeat behaviors incessantly without sleeping.>The fish show the closest behaviors of any animal researched so far to human schizophrenia. In fact, the fish seem to have about 90 percent of the genes with known risk factors for psychiatric disease.>Yoshizawa has attempted to quell the natural erratic behaviors of the cave fish with fluoxetine, commonly branded as Prozac, and clozapine.
According to wikipedia, they are eyeless and have taste buds all over their head.
They are closely related to surface, social, normie fish. It's quite interesting. Perhaps it's really hard to lose sociability once it's been evolved, and the best natural selection for asociality can do is fucking your shit up.