Koro
Koro is a psychological disorder where the person believes their penis is shrinking or retracting into their body. This syndrome mainly affects Chinese men, often accompanied by panic and a fear of death. It may stem from the belief in Chinese culture that unhealthy or abnormal sexual acts disrupt the balance of yin and yang.
These so-called "abnormal" acts include masturbation or sex with prostitutes, as only intercourse between husband and wife is considered normal. The largest Koro outbreak occurred in Singapore in 1967.
Gururumba
Gururumba affects married men in Papua New Guinea. Also called the "wild man syndrome," it’s unique because it leads to very specific and unexplained behaviors.
Under Gururumba’s influence, husbands become hyperactive, clumsy, and nearly unintelligible. They raid neighbors’ homes, stealing items they believe valuable—though these are usually worthless. Then they disappear into the forest for days and return with no memory of their actions.
Wendigo
You might have heard of this psychosis from movies—those suffering from Wendigo syndrome become cannibals. It was mainly observed among Native Americans, where people suddenly developed cravings for human flesh. Both Native healers and Western doctors tried treating this condition in their own ways.
Records show that when treatment failed and the Wendigo sufferer became violent and threatening, they were sometimes executed to protect others.
Shenkui
Another mental disorder rooted in Chinese culture, Shenkui causes insomnia, nightmares, panic, and constant anxiety. Other symptoms include dizziness, back pain, general fatigue, and weakness without any physical cause.
Some doctors believe Shenkui develops when a person has too much sex or masturbates frequently, leading to sperm loss. In Chinese culture, sperm symbolizes life and vitality, so Shenkui likely reflects a fear of losing one’s life force.
Berzerker
The Berzerker syndrome affected northern peoples. This rage didn’t just strike in battle but also during physical labor, driving men to perform superhuman feats.
Symptoms started with trembling and teeth chattering, followed by a flushed face. Then the person became hot-headed and began rampaging, often roaring like wild animals. During these episodes, men bit the edges of their shields and attacked anyone in their path. Afterward, they became dull and weak—a state that could last for days.
